air读写文件

试验了好多遍，好伤心
<?xml version="1.0" encoding="utf-8"?>
<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" xmlns:filesystem="flash.filesystem.*">
	<mx:Script>
		<![CDATA[
			import mx.controls.Alert;
			import flash.filesystem.File;
			
			public function test():void{
				
				ta.text="fileApplicationDirectory:"+File.applicationDirectory.url+"\n";
				ta.text+="fileApplicationDirectory"+File.applicationStorageDirectory.url+"\n";
				ta.text+="filedesktop"+File.desktopDirectory.url+"\n"
				ta.text+="fileDocumentsDirectorys"+File.documentsDirectory.url+"\n";
				
				
				var fileStream:FileStream=new FileStream;
//				var file:File=File.desktopDirectory.resolvePath("txt1.txt");
				mx.controls.Alert.show(File.applicationDirectory.nativePath);
				var file:File=new File(File.applicationDirectory.nativePath+"\\hello3.txt");
				
				//file.resolvePath("/hello.txt");
//				file=File.applicationDirectory;
				//file.resolvePath("hello.txt");
				//file.resolvePath("str.txt");
//				file.create\\\\
//				mx.controls.Alert.show(file.getRelativePath(file,false)+"当前目录");
//				mx.controls.Alert.show(file.nativePath+"nativepaht");
				//file:///C:/Documents%20and%20Settings/Administrator/%e6%a1%8c%e9%9d%a2/txt1.txt
				
					//C:\Documents and Settings\Administrator\桌面\txt1.txt
				//var file:File=FileresolvePath("./testFile.txt");
				//ta.text+=file.url;
				
				
				fileStream.open(file,FileMode.WRITE);
			
				fileStream.writeInt(232323);
				
				fileStream.close();
				mx.controls.Alert.show("write"+file.nativePath);
				
//				mx.controls.Alert.show(file.nativePath);
//				mx.controls.Alert.show(file.url);
			}
		]]>
	</mx:Script>
	<mx:TextArea width="100%" height="100%" wordWrap="true" id="ta">
		
	</mx:TextArea>
	<mx:Button>
		<mx:click>
			<![CDATA[
				test();
			]]>
		</mx:click>
	</mx:Button>
	<filesystem:File>
		
	</filesystem:File>
</mx:WindowedApplication>