AIR中的文件系统控件

　写AIR的过程中，可能会用到文件系统的相关控件。比如选择某一目录，浏览文件列表等。

AIR中有三种比较常用的列表类组件 --- List、Tree、DataGrid，它们的效果分别如下图所示：

分别对应：FileSystemList、FileSystemTree、FileSystemDataGrid

<?xml version="1.0" encoding="utf-8"?>
<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical"
                        title="....x"
                        windowComplete="inited()">

    <mx:Script>
        <![CDATA[
            import mx.events.FileEvent;

            private function inited():void
            {
                fileCB.directory = File.documentsDirectory;
            }

            private function changeHandler(evt:FileEvent):void
            {
                trace(evt.file.nativePath);
            }

        ]]>
    </mx:Script>

    <mx:HBox width="100%">

        <mx:FileSystemComboBox id="fileCB" directory="{fileList.directory}" directoryChange="changeHandler(event)" />

        <mx:FileSystemList id="fileList" directory="{fileCB.directory}" />

    </mx:HBox>

    <mx:HBox width="100%" height="100%">

        <mx:FileSystemTree id="fileTree" width="300" height="400" directory="{FileSystemTree.COMPUTER}" />

        <mx:FileSystemDataGrid id="fileGrid" width="100%" height="100%" directory="{File.desktopDirectory}" />

    </mx:HBox>



</mx:WindowedApplication>

还有一个对文件操作的常用操作：

1）、浏览文件，打开一个对话框，选择一个或多个文件；

private var file:File = new File();
private var fileFilter:FileFilter = new FileFilter("Text", "*.txt; *.html; *.xml");
private var imgFilter:FileFilter = new FileFilter("图片", "*.jpg; *.png; *.jpeg");

private function inited():void
{
      file.addEventListener(Event.SELECT, onSelectHandler);
    file.addEventListener(Event.CANCEL, onCancelHandler);
    file.addEventListener(FileListEvent.SELECT_MULTIPLE, onSelectMultipleHandler);

      file.browseForOpen("Open File", [fileFilter, imgFilter]);
    file.browseForOpenMultiple("Open File", [fileFilter, imgFilter]);
}

private function onSelectHandler(evt:Event):void
{

}

private function onCancelHandler(evt:Event):void
{

}

private function onSelectMultipleHandler(evt:FileEvent):void
{

}

2）、保存文件

 

private function inited():void
{
    file = File.desktopDirectory;
    file.browseForSave("另存为");

    file.addEventListener(Event.SELECT, onSelectHandler);
}

private function onSelectHandler(evt:Event):void
{
    var file:File = evt.target as File;
    var stream:FileStream = new FileStream();

    stream.open(file, FileMode.WRITE);
    stream.writeUTFBytes("Hello AIR");
    stream.close();
}

3）、其它应用程序的技巧，例如：让应用程序始终“保持在其它窗口的顶部”(alwaysInFront=true)、应用程序在任务栏中，它的右击菜单、顶部的状态栏操作等