| Package | flash.filesystem |
| Class | public class FileStream |
| Inheritance | FileStream  EventDispatcher Object |
| Implements | IDataInput, IDataOutput |
| Runtime Versions: | AIR 1.0 |
open() method or asynchronously by calling the openAsync() method.
The advantage of opening files asynchronously is that other code can execute while Adobe AIR
runs read and write processes in the background. When opened asynchronously, progress events
are dispatched as operations proceed.
A File object that is opened synchronously behaves much like a ByteArray object; a file opened asynchronously behaves much like a Socket or URLStream object. When a File object is opened synchronously, the caller pauses while the requested data is read from or written to the underlying file. When opened asynchronously, any data written to the stream is immediately buffered and later written to the file.
Whether reading from a file synchronously or asynchronously, the actual read methods are synchronous.
In both cases they read from data that is currently "available." The difference is that when reading
synchronously all of the data is available at all times, and when reading asynchronously data becomes
available gradually as the data streams into a read buffer. Either way, the data that can be synchronously
read at the current moment is represented by the bytesAvailable property.
An application that is processing asynchronous input typically registers for progress events
and consumes the data as it becomes available by calling read methods. Alternatively, an application can
simply wait until all of the data is available by registering for the complete event and
processing the entire data set when the complete event is dispatched.
More examples
Hide Inherited Public Properties
Show Inherited Public Properties| Property | Defined By | ||
|---|---|---|---|
| bytesAvailable : uint [read-only]
Returns the number of bytes of data available for reading
in the input buffer. | FileStream | ||
 | constructor : Object
A reference to the class object or constructor function for a given object instance. | Object | |
| endian : String
The byte order for the data, either the BIG_ENDIAN or LITTLE_ENDIAN constant
from the Endian class. | FileStream | ||
| objectEncoding : uint
Specifies whether the AMF3 or AMF0 format is used when writing or reading binary data by using the
readObject() or writeObject() method. | FileStream | ||
| position : Number
The current position in the file. | FileStream | ||
| readAhead : Number
The minimum amount of data to read from disk when reading files asynchronously. | FileStream | ||
| Method | Defined By | ||
|---|---|---|---|
Creates a FileStream object. | FileStream | ||
| addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void
Registers an event listener object with an EventDispatcher object so that the listener
receives notification of an event. | EventDispatcher | |
Closes the FileStream object. | FileStream | ||
|
Dispatches an event into the event flow. | EventDispatcher | |
|
Checks whether the EventDispatcher object has any listeners registered for a specific type
of event. | EventDispatcher | |
|
Indicates whether an object has a specified property defined. | Object | |
|
Indicates whether an instance of the Object class is in the prototype chain of the object specified
as the parameter. | Object | |
Opens the FileStream object synchronously, pointing to the file specified by the file parameter. | FileStream | ||
Opens the FileStream object asynchronously, pointing to the file specified by the file parameter. | FileStream | ||
|
Indicates whether the specified property exists and is enumerable. | Object | |
Reads a Boolean value from the file stream, byte stream, or byte array. | FileStream | ||
Reads a signed byte from the file stream, byte stream, or byte array. | FileStream | ||
Reads the number of data bytes, specified by the length parameter,
from the file stream, byte stream, or byte array. | FileStream | ||
Reads an IEEE 754 double-precision floating point number from the file stream, byte stream, or byte array. | FileStream | ||
Reads an IEEE 754 single-precision floating point number from the file stream, byte stream, or byte array. | FileStream | ||
Reads a signed 32-bit integer from the file stream, byte stream, or byte array. | FileStream | ||
Reads a multibyte string of specified length from the file stream, byte stream, or byte array using the
specified character set. | FileStream | ||
Reads an object from the file stream, byte stream, or byte array, encoded in AMF
serialized format. | FileStream | ||
Reads a signed 16-bit integer from the file stream, byte stream, or byte array. | FileStream | ||
Reads an unsigned byte from the file stream, byte stream, or byte array. | FileStream | ||
Reads an unsigned 32-bit integer from the file stream, byte stream, or byte array. | FileStream | ||
Reads an unsigned 16-bit integer from the file stream, byte stream, or byte array. | FileStream | ||
Reads a UTF-8 string from the file stream, byte stream, or byte array. | FileStream | ||
Reads a sequence of UTF-8 bytes from the byte stream or byte array and returns a string. | FileStream | ||
|
Removes a listener from the EventDispatcher object. | EventDispatcher | |
|
Sets the availability of a dynamic property for loop operations. | Object | |
|
Returns the string representation of this object, formatted according to locale-specific conventions. | Object | |
|
Returns the string representation of the specified object. | Object | |
Truncates the file at the position specified by the position property of the FileStream
object. | FileStream | ||
|
Returns the primitive value of the specified object. | Object | |
|
Checks whether an event listener is registered with this EventDispatcher object or any of
its ancestors for the specified event type. | EventDispatcher | |
Writes a Boolean value. | FileStream | ||
Writes a byte. | FileStream | ||
Writes a sequence of bytes from the
specified byte array, bytes,
starting at the byte specified by offset
(using a zero-based index)
with a length specified by length,
into the file stream, byte stream, or byte array. | FileStream | ||
Writes an IEEE 754 double-precision (64-bit) floating point number. | FileStream | ||
Writes an IEEE 754 single-precision (32-bit) floating point number. | FileStream | ||
Writes a 32-bit signed integer. | FileStream | ||
Writes a multibyte string to the file stream, byte stream, or byte array, using the specified character set. | FileStream | ||
Writes an object to the file stream, byte stream, or byte array, in AMF serialized
format. | FileStream | ||
Writes a 16-bit integer. | FileStream | ||
Writes a 32-bit unsigned integer. | FileStream | ||
Writes a UTF-8 string to the file stream, byte stream, or byte array. | FileStream | ||
Writes a UTF-8 string. | FileStream | ||
| Event | Summary | Defined By | ||
|---|---|---|---|---|
| [broadcast event] Dispatched when the Flash Player or AIR application gains operating system focus and becomes active. | EventDispatcher | ||
| Indicates that the stream has been closed by an explicit call to the close() method. | FileStream | |||
| Signals that the end of the stream has been reached. | FileStream | |||
| [broadcast event] Dispatched when the Flash Player or AIR application operating loses system focus and is becoming inactive. | EventDispatcher | ||
| Indicates that an error occurred during an asynchronous file I/O operation. | FileStream | |||
| Signals that buffered data has been written to the file. | FileStream | |||
| Signals the availability of new data on the stream. | FileStream | |||
bytesAvailable | property |
bytesAvailable:uint [read-only] | Runtime Versions: | AIR 1.0 |
Returns the number of bytes of data available for reading
in the input buffer.
User code must call bytesAvailable to ensure
that sufficient data is available before trying to read
it with one of the read methods.
Implementation
public function get bytesAvailable():uint endian | property |
objectEncoding | property |
objectEncoding:uint| Runtime Versions: | AIR 1.0 |
Specifies whether the AMF3 or AMF0 format is used when writing or reading binary data by using the
readObject() or writeObject() method.
The value is a constant from the ObjectEncoding class. By default, the AMF3 format is used.
Implementation
public function get objectEncoding():uint public function set objectEncoding(value:uint):voidRelated API Elements
position | property |
position:Number| Runtime Versions: | AIR 1.0 |
The current position in the file.
This value is modified in any of the following ways:
- When you set the property explicitly
- When reading from the FileStream object (by using one of the read methods)
- When writing to the FileStream object
The position is defined as a Number (instead of uint) in order to support files larger than 232 bytes in length. The value of this property is always a whole number less than 253. If you set this value to a number with a fractional component, the value is rounded down to the nearest integer.
When reading a file asyncronously, if you set the position property,
the application begins filling the read buffer with the data starting at the specified
position, and the bytesAvailable property may be set to 0. Wait for a complete
event before using a read method to read data; or wait for a progress event
and check the bytesAvailable property before using a read method.
Implementation
public function get position():Number public function set position(value:Number):voidMore examples
The read buffer and the bytesAvailable property of a FileStream object
Example ( How to use this example )
position property of the FileStream object
is updated as the application reads data from a file.
import flash.fileSystem.*;
import flash.utils.ByteArray;
import flash.events.Event;
var sourceFile:File = File.documentsDirectory.resolvePath("Apollo Test/test.txt");
var stream:FileStream = new FileStream();
stream.addEventListener(Event.COMPLETE, readBytes);
stream.openAsync(sourceFile, FileMode.READ);
function readBytes(e:Event):void {
var bytes:ByteArray = new ByteArray();
trace("position 0:", stream.position); // 0
bytes[0] = stream.readByte();
trace("position 1:", stream.position); // 1
fileStream.readBytes(bytes, stream.position, 4);
trace("position 2:", stream.position); // 5
stream.close();
}
readAhead | property |
readAhead:Number| Runtime Versions: | AIR 1.0 |
The minimum amount of data to read from disk when reading files asynchronously.
This property specifies how much data an asynchronous stream attempts to read
beyond the current position. Data is read in blocks based on the file system page size.
Thus if you set readAhead to 9,000 on a computer system with an 8KB (8192 byte)
page size, the runtime reads ahead 2 blocks, or 16384 bytes at a time.
The default value of this property is infinity: by default
a file that is opened to read asynchronously reads as far as the end of the file.
Reading data from the read buffer does not change the value of the readAhead
property. When you read data from the buffer, new data is read in to refill the read buffer.
The readAhead property has no effect on a file that is opened synchronously.
As data is read in asynchronously, the FileStream object dispatches progress events. In the
event handler method for the progress event, check to see that the required number of bytes
is available (by checking the bytesAvailable property), and then read the data from the
read buffer by using a read method.
Implementation
public function get readAhead():Number public function set readAhead(value:Number):voidExample ( How to use this example )
readAhead property to limit
the amount of data read into a file to 100 bytes:
import flash.filesystem.*;
var file:File = File.desktopDirectory.resolvePath("test.txt");
var fileStream:FileStream = new FileStream();
fileStream.readAhead = 100;
fileStream.addEventListener(ProgressEvent.PROGRESS, readProgressHandler)
fileStream.openAsync(file, FileMode.READ);
var results:ByteArray;
function readProgressHandler(event:ProgressEvent):void {
if (fileStream.bytesAvailable >= 100) {
fileStream.readBytes(results, 0, 100);
}
}
FileStream | () | Constructor |
public function FileStream()| Runtime Versions: | AIR 1.0 |
Creates a FileStream object.
Use the open()
or openAsync() method to open a file.
Related API Elements
close | () | method |
public function close():void| Runtime Versions: | AIR 1.0 |
Closes the FileStream object.
You cannot read or write any data after you call the close() method. If the file
was opened asynchronously (the FileStream object used the openAsync() method to open the file),
calling the close() method causes the object to dispatch the close event.
Closing the application automatically closes all files associated with FileStream objects in the application.
However, it is best to register for a closed event on all FileStream objects opened asynchronously
that have pending data to write, before closing the application (to ensure that data is written).
You can reuse the FileStream object by calling the open() or the openAsync()
method. This closes any file associated with the FileStream object, but the object does not dispatch the
close event.
For a FileStream object opened asynchronously (by using the openAsync() method),
even if you call the close() event for a FileStream object and delete properties and variables that
reference the object, the FileStream object is not garbage collected as long as there are pending operations and
event handlers are registered for their completion. In particular, an otherwise unreferenced FileStream object
persists as long as any of the following are still possible:
- For file reading operations, the end of the file has not been reached (and the
completeevent has not been dispatched). - Output data is still available to written, and output-related events (such as the
outputProgressevent or theioErrorevent) have registered event listeners.
Events
close: — The file, which was opened asynchronously, is closed.
|
Related API Elements
Example ( How to use this example )
close()
method of the FileStream object closes the file when the data is written.
import flash.filesystem.*;
import flash.events.Event;
var file:File = File.documentsDirectory;
file = file.resolvePath("Apollo Test/test.txt");
var fileStream:FileStream = new FileStream();
fileStream.openAsync(file, FileMode.WRITE);
fileStream.writeUTFBytes("Hello");
fileStream.addEventListener(Event.CLOSE, fileClosed);
fileStream.close();
function fileClosed(event:Event):void {
trace("closed");
}
close()
method of the FileStream object closes the file when the data is written.
import flash.filesystem.*;
var file:File = File.documentsDirectory;
file = file.resolvePath("Apollo Test/test.txt");
var fileStream:FileStream = new FileStream();
fileStream.open(file, FileMode.WRITE);
fileStream.writeUTF("Hello");
fileStream.close();
open | () | method |
public function open(file:File, fileMode:String):void| Runtime Versions: | AIR 1.0 |
Opens the FileStream object synchronously, pointing to the file specified by the file parameter.
If the FileStream object is already open, calling the method closes the file before opening
and no further events (including close) are delivered for the previously opened file.
On systems that support file locking, a file opened in "write" or "update" mode (FileMode.WRITE
or FileMode.UPDATE) is not readable until it is closed.
Once you are done performing operations on the file, call the close() method of the FileStream
object. Some operating systems limit the number of concurrently open files.
Parameters
file:File — The File object specifying the file to open.
| |
fileMode:String — A string from the FileMode class that defines the capabilities of the FileStream, such as
the ability to read from or write to the file.
|
Throws
IOError — The file does not exist; you do not have adequate permissions to
open the file; you are opening a file for read access, and you do not have read permissions;
or you are opening a file for write access, and you do not have write permissions.
| |
SecurityError — The file location is in the application directory, and the fileMode
parameter is set to "append", "update", or "write" mode.
|
More examples
Example: Reading an XML file into an XML object
Example: Reading and writing data with random access
Related API Elements
Example ( How to use this example )
import flash.filesystem.*;
var file:File = File.documentsDirectory;
file = file.resolvePath("Apollo Test/test.txt");
var fileStream:FileStream = new FileStream();
fileStream.open(file, FileMode.READ);
var str:String = fileStream.readMultiByte(file.size, File.systemCharset);
trace(str);
fileStream.close();
openAsync | () | method |
public function openAsync(file:File, fileMode:String):void| Runtime Versions: | AIR 1.0 |
Opens the FileStream object asynchronously, pointing to the file specified by the file parameter.
If the FileStream object is already open, calling the method closes the file before opening
and no further events (including close) are delivered for the previously opened file.
If the fileMode parameter is set to FileMode.READ or
FileMode.UPDATE, AIR reads data into the input buffer as soon as the file is opened,
and progress and open events are dispatched as the data is read to
the input buffer.
On systems that support file locking, a file opened in "write" or "update" mode (FileMode.WRITE
or FileMode.UPDATE) is not readable until it is closed.
Once you are done performing operations on the file, call the close() method of the FileStream
object. Some operating systems limit the number of concurrently open files.
Parameters
file:File — The File object specifying the file to open.
| |
fileMode:String — A string from the FileMode class that defines the capabilities of the FileStream, such as
the ability to read from or write to the file.
|
Events
ioError: — The file does not exist; you do not have adequate permissions to
open the file; you are opening a file for read access, and you do not have read permissions;
or you are opening a file for write access, and you do not have write permissions.
| |
progress: — Dispatched as data is read to the input buffer. (The file must be opened
with the fileMode parameter set to FileMode.READ or
FileMode.UPDATE.)
| |
complete: — The file data has been read to the input buffer. (The file must be opened with
the fileMode parameter set to FileMode.READ or
FileMode.UPDATE.)
|
Throws
SecurityError — The file location is in the application directory, and the fileMode parameter
is set to "append", "update", or "write" mode.
|
More examples
Related API Elements
Example ( How to use this example )
import flash.filesystem.*;
import flash.events.Event;
var file:File = File.documentsDirectory;
file = file.resolvePath("Apollo Test/test.txt");
var fileStream:FileStream = new FileStream();
fileStream.addEventListener(Event.COMPLETE, fileCompleteHandler)
fileStream.openAsync(file, FileMode.READ);
function fileCompleteHandler(event:Event):void {
var str:String = fileStream.readMultiByte(fileStream.bytesAvailable, File.systemCharset);
trace(str);
fileStream.close();
}
readBoolean | () | method |
public function readBoolean():Boolean| Runtime Versions: | AIR 1.0 |
Reads a Boolean value from the file stream, byte stream, or byte array. A single byte is read
and true is returned if the byte is nonzero,
false otherwise.
Boolean — A Boolean value, true if the byte is nonzero,
false otherwise.
|
Events
ioError: — The file cannot be read or the file is not open. This event is dispatched
only for files opened for asynchronous operations (by using the openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
read capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be read (for example, because the file is missing).
| |
EOFError — The position specfied for reading data exceeds the number of bytes available
(specified by the bytesAvailable property).
|
readByte | () | method |
public function readByte():int| Runtime Versions: | AIR 1.0 |
Reads a signed byte from the file stream, byte stream, or byte array.
Returnsint — The returned value is in the range -128 to 127.
|
Events
ioError: — The file cannot be read or the file is not open. This event is dispatched
only for files opened for asynchronous operations (by using the openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
read capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be read (for example, because the file is missing).
| |
EOFError — The position specfied for reading data exceeds the number of bytes available
(specified by the bytesAvailable property).
|
readBytes | () | method |
public function readBytes(bytes:ByteArray, offset:uint = 0, length:uint = 0):void| Runtime Versions: | AIR 1.0 |
Reads the number of data bytes, specified by the length parameter,
from the file stream, byte stream, or byte array. The bytes are read into the
ByteArray objected specified by the bytes parameter, starting at
the position specified by offset.
Parameters
bytes:ByteArray — The ByteArray object to read
data into.
| |
offset:uint (default = 0)bytes parameter at which data
read should begin.
| |
length:uint (default = 0) |
Events
ioError: — The file cannot be read or the file is not open. This event is dispatched
only for files opened for asynchronous operations (by using the openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
read capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be read (for example, because the file is missing).
| |
EOFError — The position specfied for reading data exceeds the number of bytes available
(specified by the bytesAvailable property).
|
More examples
readDouble | () | method |
public function readDouble():Number| Runtime Versions: | AIR 1.0 |
Reads an IEEE 754 double-precision floating point number from the file stream, byte stream, or byte array.
ReturnsNumber — An IEEE 754 double-precision floating point number.
|
Events
ioError: — The file cannot be read or the file is not open. This event is dispatched
only for files opened for asynchronous operations (by using the openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
read capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be read (for example, because the file is missing).
| |
EOFError — The position specfied for reading data exceeds the number of bytes available
(specified by the bytesAvailable property).
|
readFloat | () | method |
public function readFloat():Number| Runtime Versions: | AIR 1.0 |
Reads an IEEE 754 single-precision floating point number from the file stream, byte stream, or byte array.
ReturnsNumber — An IEEE 754 single-precision floating point number.
|
Events
ioError: — The file cannot be read or the file is not open. This event is dispatched
only for files opened for asynchronous operations (by using the openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
read capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be read (for example, because the file is missing).
| |
EOFError — The position specfied for reading data exceeds the number of bytes available
(specified by the bytesAvailable property).
|
readInt | () | method |
public function readInt():int| Runtime Versions: | AIR 1.0 |
Reads a signed 32-bit integer from the file stream, byte stream, or byte array.
Returnsint — The returned value is in the range -2147483648 to 2147483647.
|
Events
ioError: — The file cannot be read or the file is not open. This event is dispatched
only for files opened for asynchronous operations (by using the openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
read capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be read (for example, because the file is missing).
| |
EOFError — The position specfied for reading data exceeds the number of bytes available
(specified by the bytesAvailable property).
|
readMultiByte | () | method |
public function readMultiByte(length:uint, charSet:String):String| Runtime Versions: | AIR 1.0 |
Reads a multibyte string of specified length from the file stream, byte stream, or byte array using the specified character set.
Parameters
length:uint — The number of bytes from the byte stream to read.
| |
charSet:String — The string denoting the character set to use to interpret the bytes.
Possible character set strings include "shift-jis", "cn-gb",
"iso-8859-1", and others.
For a complete list, see Supported Character Sets.
Note: If the value for the |
String — UTF-8 encoded string.
|
Events
ioError: — The file cannot be read or the file is not open. This event is dispatched
only for files opened for asynchronous operations (by using the openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
read capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be read (for example, because the file is missing).
| |
EOFError — The position specfied for reading data exceeds the number of bytes available
(specified by the bytesAvailable property).
|
Related API Elements
readObject | () | method |
public function readObject():*| Runtime Versions: | AIR 1.0 |
Reads an object from the file stream, byte stream, or byte array, encoded in AMF serialized format.
Returns* — The deserialized object
|
Events
ioError: — The file cannot be read or the file is not open. This event is dispatched
only for files opened for asynchronous operations (by using the openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
read capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be read (for example, because the file is missing).
| |
EOFError — The position specfied for reading data exceeds the number of bytes available
(specified by the bytesAvailable property).
|
Related API Elements
readShort | () | method |
public function readShort():int| Runtime Versions: | AIR 1.0 |
Reads a signed 16-bit integer from the file stream, byte stream, or byte array.
Returnsint — The returned value is in the range -32768 to 32767.
|
Events
ioError: — The file cannot be read or the file is not open. This event is dispatched
only for files opened for asynchronous operations (by using the openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
read capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be read (for example, because the file is missing).
| |
EOFError — The position specfied for reading data exceeds the number of bytes available
(specified by the bytesAvailable property).
|
readUnsignedByte | () | method |
public function readUnsignedByte():uint| Runtime Versions: | AIR 1.0 |
Reads an unsigned byte from the file stream, byte stream, or byte array.
Returnsuint — The returned value is in the range 0 to 255.
|
Events
ioError: — The file cannot be read or the file is not open. This event is dispatched
only for files opened for asynchronous operations (by using the openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
read capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be read (for example, because the file is missing).
| |
EOFError — The position specfied for reading data exceeds the number of bytes available
(specified by the bytesAvailable property).
|
readUnsignedInt | () | method |
public function readUnsignedInt():uint| Runtime Versions: | AIR 1.0 |
Reads an unsigned 32-bit integer from the file stream, byte stream, or byte array.
Returnsuint — The returned value is in the range 0 to 4294967295.
|
Events
ioError: — The file cannot be read or the file is not open. This event is dispatched
only for files opened for asynchronous operations (by using the openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
read capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be read (for example, because the file is missing).
| |
EOFError — The position specfied for reading data exceeds the number of bytes available
(specified by the bytesAvailable property).
|
readUnsignedShort | () | method |
public function readUnsignedShort():uint| Runtime Versions: | AIR 1.0 |
Reads an unsigned 16-bit integer from the file stream, byte stream, or byte array.
Returnsuint — The returned value is in the range 0 to 65535.
|
Events
ioError: — The file cannot be read or the file is not open. This event is dispatched
only for files opened for asynchronous operations (by using the openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
read capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be read (for example, because the file is missing).
| |
EOFError — The position specfied for reading data exceeds the number of bytes available
(specified by the bytesAvailable property).
|
readUTF | () | method |
public function readUTF():String| Runtime Versions: | AIR 1.0 |
Reads a UTF-8 string from the file stream, byte stream, or byte array. The string is assumed to be prefixed with an unsigned short indicating the length in bytes.
This method is similar to the readUTF()
method in the Java® IDataInput interface.
String — A UTF-8 string produced by the byte representation of characters.
|
Events
ioError: — The file cannot be read or the file is not open. This event is dispatched
only for files opened for asynchronous operations (by using the openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
read capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be read (for example, because the file is missing).
| |
EOFError — The position specfied for reading data exceeds the number of bytes available
(specified by the bytesAvailable property).
|
readUTFBytes | () | method |
public function readUTFBytes(length:uint):String| Runtime Versions: | AIR 1.0 |
Reads a sequence of UTF-8 bytes from the byte stream or byte array and returns a string.
Parameters
length:uint — The number of bytes to read.
|
String — A UTF-8 string produced by the byte representation of characters of the specified length.
|
Events
ioError: — The file cannot be read or the file is not open. This event is dispatched
only for files opened for asynchronous operations (by using the openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
read capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be read (for example, because the file is missing).
| |
EOFError — The position specfied for reading data exceeds the number of bytes available
(specified by the bytesAvailable property).
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truncate | () | method |
public function truncate():void| Runtime Versions: | AIR 1.0 |
Truncates the file at the position specified by the position property of the FileStream
object.
Bytes from the position specified by the position property to the end of the file
are deleted. The file must be open for writing.
Throws
IllegalOperationError — The file is not open for writing.
|
Related API Elements
Example ( How to use this example )
import flash.filesystem.*;
var file:File = File.documentsDirectory;
file = file.resolvePath("Apollo Test/test.txt");
var fileStream:FileStream = new FileStream();
fileStream.open(file, FileMode.UPDATE);
if (file.size > 100) {
fileStream.position = 100;
fileStream.truncate();
}
fileStream.close();
var file:File = File.documentsDirectory;
file = file.resolvePath("Apollo Test/test.txt");
var fileStream:FileStream = new FileStream();
fileStream.openAsync(file, FileMode.UPDATE);
trace("start", file.size)
if (file.size > 100) {
fileStream.position = 100;
fileStream.truncate();
}
fileStream.addEventListener(Event.CLOSE, fileClosed);
fileStream.close();
function fileClosed(event:Event):void {
trace("closed", file.size);
}
writeBoolean | () | method |
public function writeBoolean(value:Boolean):void| Runtime Versions: | AIR 1.0 |
Writes a Boolean value. A single byte is written according to the value parameter,
either 1 if true or 0 if false.
Parameters
value:Boolean — A Boolean value determining which byte is written. If the parameter is true,
1 is written; if false, 0 is written.
|
Events
ioError: — You cannot write to the file (for example, because the file is missing).
This event is dispatched only for files that have been opened for asynchronous operations (by using the
openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
write capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be written (for example, because the file is missing).
|
writeByte | () | method |
public function writeByte(value:int):void| Runtime Versions: | AIR 1.0 |
Writes a byte. The low 8 bits of the parameter are used; the high 24 bits are ignored.
Parameters
value:int — A byte value as an integer.
|
Events
ioError: — You cannot write to the file (for example, because the file is missing).
This event is dispatched only for files that have been opened for asynchronous operations (by using the
openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
write capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be written (for example, because the file is missing).
|
writeBytes | () | method |
public function writeBytes(bytes:ByteArray, offset:uint = 0, length:uint = 0):void| Runtime Versions: | AIR 1.0 |
Writes a sequence of bytes from the
specified byte array, bytes,
starting at the byte specified by offset
(using a zero-based index)
with a length specified by length,
into the file stream, byte stream, or byte array.
If the length parameter is omitted, the default
length of 0 is used and the entire buffer starting at
offset is written.
If the offset parameter is also omitted, the entire buffer is
written.
If the offset or length parameter
is out of range, they are clamped to the beginning and end
of the bytes array.
Parameters
bytes:ByteArray — The byte array to write.
| |
offset:uint (default = 0) | |
length:uint (default = 0) |
Events
ioError: — You cannot write to the file (for example, because the file is missing).
This event is dispatched only for files that have been opened for asynchronous operations (by using the
openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
write capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be written (for example, because the file is missing).
|
writeDouble | () | method |
public function writeDouble(value:Number):void| Runtime Versions: | AIR 1.0 |
Writes an IEEE 754 double-precision (64-bit) floating point number.
Parameters
value:Number — A double-precision (64-bit) floating point number.
|
Events
ioError: — You cannot write to the file (for example, because the file is missing).
This event is dispatched only for files that have been opened for asynchronous operations (by using the
openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
write capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be written (for example, because the file is missing).
|
writeFloat | () | method |
public function writeFloat(value:Number):void| Runtime Versions: | AIR 1.0 |
Writes an IEEE 754 single-precision (32-bit) floating point number.
Parameters
value:Number — A single-precision (32-bit) floating point number.
|
Events
ioError: — You cannot write to the file (for example, because the file is missing).
This event is dispatched only for files that have been opened for asynchronous operations (by using the
openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
write capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be written (for example, because the file is missing).
|
writeInt | () | method |
public function writeInt(value:int):void| Runtime Versions: | AIR 1.0 |
Writes a 32-bit signed integer.
Parameters
value:int — A byte value as a signed integer.
|
Events
ioError: — You cannot write to the file (for example, because the file is missing).
This event is dispatched only for files that have been opened for asynchronous operations (by using the
openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
write capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be written (for example, because the file is missing).
|
writeMultiByte | () | method |
public function writeMultiByte(value:String, charSet:String):void| Runtime Versions: | AIR 1.0 |
Writes a multibyte string to the file stream, byte stream, or byte array, using the specified character set.
Parameters
value:String — The string value to be written.
| |
charSet:String — The string denoting the character set to use. Possible character set strings
include "shift-jis", "cn-gb", "iso-8859-1", and others.
For a complete list, see Supported Character Sets.
|
Events
ioError: — You cannot write to the file (for example, because the file is missing).
This event is dispatched only for files that have been opened for asynchronous operations (by using the
openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
write capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be written (for example, because the file is missing).
|
Related API Elements
writeObject | () | method |
public function writeObject(object:*):void| Runtime Versions: | AIR 1.0 |
Writes an object to the file stream, byte stream, or byte array, in AMF serialized format.
Parameters
object:* — The object to be serialized.
|
Events
ioError: — You cannot write to the file (for example, because the file is missing).
This event is dispatched only for files that have been opened for asynchronous operations (by using the
openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
write capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be written (for example, because the file is missing).
|
Related API Elements
writeShort | () | method |
public function writeShort(value:int):void| Runtime Versions: | AIR 1.0 |
Writes a 16-bit integer. The low 16 bits of the parameter are used; the high 16 bits are ignored.
Parameters
value:int — A byte value as an integer.
|
Events
ioError: — You cannot write to the file (for example, because the file is missing).
This event is dispatched only for files that have been opened for asynchronous operations (by using the
openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
write capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be written (for example, because the file is missing).
|
writeUnsignedInt | () | method |
public function writeUnsignedInt(value:uint):void| Runtime Versions: | AIR 1.0 |
Writes a 32-bit unsigned integer.
Parameters
value:uint — A byte value as an unsigned integer.
|
Events
ioError: — You cannot write to the file (for example, because the file is missing).
This event is dispatched only for files that have been opened for asynchronous operations (by using the
openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
write capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be written (for example, because the file is missing).
|
writeUTF | () | method |
public function writeUTF(value:String):void| Runtime Versions: | AIR 1.0 |
Writes a UTF-8 string to the file stream, byte stream, or byte array. The length of the UTF-8 string in bytes is written first, as a 16-bit integer, followed by the bytes representing the characters of the string.
Parameters
value:String — The string value to be written.
|
Events
ioError: — You cannot write to the file (for example, because the file is missing).
This event is dispatched only for files that have been opened for asynchronous operations (by using the
openAsync() method).
|
Throws
RangeError — If the length of the string is larger than
65535.
| |
IOError — The file has not been opened; the file has been opened, but it was not opened with
write capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be written (for example, because the file is missing).
|
writeUTFBytes | () | method |
public function writeUTFBytes(value:String):void| Runtime Versions: | AIR 1.0 |
Writes a UTF-8 string. Similar to writeUTF(),
but does not prefix the string with a 16-bit length word.
Parameters
value:String — The string value to be written.
|
Events
ioError: — You cannot write to the file (for example, because the file is missing).
This event is dispatched only for files that have been opened for asynchronous operations (by using the
openAsync() method).
|
Throws
IOError — The file has not been opened; the file has been opened, but it was not opened with
write capabilities; or for a file that has been opened for synchronous operations (by using the
open() method), the file cannot be written (for example, because the file is missing).
|
close | Event |
flash.events.Eventproperty Event.type =
flash.events.Event.CLOSE| Runtime Versions: | AIR 1.0 |
Indicates that the stream has been
closed by an explicit call to the close() method.
Event.CLOSE constant defines the value of the type property of a close event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The object whose connection has been closed. |
Related API Elements
complete | Event |
flash.events.Eventproperty Event.type =
flash.events.Event.COMPLETE| Runtime Versions: | AIR 1.0 |
Signals that the end of the stream has been reached.
TheEvent.COMPLETE constant defines the value of the type property of a complete event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The network object that has completed loading. |
Related API Elements
ioError | Event |
flash.events.IOErrorEventproperty IOErrorEvent.type =
flash.events.IOErrorEvent.IO_ERROR| Runtime Versions: | AIR 1.0 |
Indicates that an error occurred during an asynchronous file I/O operation.
Defines the value of thetype property of an ioError event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
errorID | A reference number associated with the specific error (AIR only). |
target | The network object experiencing the input/output error. |
text | Text to be displayed as an error message. |
outputProgress | Event |
flash.events.OutputProgressEventproperty OutputProgressEvent.type =
flash.events.OutputProgressEvent.OUTPUT_PROGRESS| Runtime Versions: | AIR 1.0 |
Signals that buffered data has been written to the file.
Defines the value of thetype property of an outputProgress event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
bytesPending | The number of bytes remaining to be written at the time the listener processes the event. |
bytesTotal | The total number of bytes that ultimately will be written if the write process succeeds. |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The FileStream object reporting progress. |
progress | Event |
flash.events.ProgressEventproperty ProgressEvent.type =
flash.events.ProgressEvent.PROGRESS| Runtime Versions: | AIR 1.0 |
Signals the availability of new data on the stream.
Defines the value of thetype property of a progress event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
bytesLoaded | The number of items or bytes loaded at the time the listener processes the event. |
bytesTotal | The total number of items or bytes that ultimately will be loaded if the loading process succeeds. |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The object reporting progress. |
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