Initializing a FileStream object, and opening and closing files

When you open a FileStream object, you make it available to read and write data to a file. You open a FileStream object by passing a File object to the open() or openAsync() method of the FileStream object:

var myFile:File = File.documentsDirectory.resolvePath("AIR Test/test.txt");
var myFileStream:FileStream = new FileStream();
myFileStream.open(myFile, FileMode.READ);

The fileMode parameter (the second parameter of the open() and openAsync() methods), specifies the mode in which to open the file: for read, write, append, or update. For details, see the previous section, FileStream open modes.

If you use the openAsync() method to open the file for asynchronous file operations, set up event listeners to handle the asynchronous events:

var myFile:File = File.documentsDirectory.resolvePath("AIR Test/test.txt");
var myFileStream:FileStream = new FileStream();
myFileStream.addEventListener(Event.COMPLETE, completeHandler);
myFileStream.addEventListener(ProgressEvent.PROGRESS, progressHandler);
myFileStream.addEventListener(IOErrorEvent.IO_Error, errorHandler);
myFileStream.openAsync(myFile, FileMode.READ);

function completeHandler(event:Event):void {
    // ...
}

function progressHandler(event:ProgressEvent):void {
    // ...
}

function errorHandler(event:IOErrorEvent):void {
    // ...
}

The file is opened for synchronous or asynchronous operations, depending upon whether you use the open() or openAsync() method. For details, see AIR file basics.

If you set the fileMode parameter to FileMode.READ or FileMode.UPDATE in the open method of the FileStream object, data is read into the read buffer as soon as you open the FileStream object. For details, see The read buffer and the bytesAvailable property of a FileStream object.

You can call the close() method of a FileStream object to close the associated file, making it available for use by other applications.