Flash/Flex学习笔记(4)：如何打开网页及Get/Post数据

flash终究只是客户端技术，所以很多时候还是需要与服务端技术(比如asp,asp.net,jsp,php之类)进行数据交互的，下面的代码演示了如何在flash中打开网页，以及用GET/POST二种方式向服务端发送数据

//按下按钮，打开网页
btnOpen.addEventListener(MouseEvent.CLICK,function(){navigateToURL(new URLRequest("http://www.g.cn/search?hl=zh-CN&q=" + encodeURIComponent(txtId.text)),"_blank");
});//以Get方式发送数据(发送就完事，不会理会服务端是否响应)
btnSend.addEventListener(MouseEvent.CLICK,function(){sendToURL(new URLRequest("/default.aspx?q=" + encodeURIComponent(txtId.text)));
});
btnPost.addEventListener(MouseEvent.CLICK,fnPostData);//以Post方式发送数据(同样：发送就完事，不会理会服务端是否响应)
function fnPostData(e:MouseEvent) {var _urlReq:URLRequest = new URLRequest();_urlReq.url = "/default.aspx";_urlReq.method = URLRequestMethod.POST;var _data:URLVariables = new URLVariables();_data.q = "菩提树下的杨过"; //即传递 q = 菩提树下的杨过,注：经测试，Flash会自动对传递的数据做encodeURIComponent处理，所以此外不能再加encodeURIComponent，否则就是二次编码了_urlReq.data = _data;sendToURL(_urlReq);
}

服务端可以这样处理：

protected void Page_Load(object sender, EventArgs e)
{string q = Request["q"];if (!string.IsNullOrEmpty(q)) {string _file = Server.MapPath("~/log.txt");File.AppendAllText(_file,q + "\t" + Request.HttpMethod + "\t" + DateTime.Now + Environment.NewLine);}
}

如果发送了数据后，还要响应服务端的结果（比如取得服务端的返回值，再继续到Flash中处理），Flash中可这样写:

var loader:URLLoader = new URLLoader();
configureListeners(loader);
var request:URLRequest=new URLRequest("/FlashHander.ashx?q=" + encodeURIComponent("菩提树下的杨过"));
try {loader.load(request);
} catch (error:Error) {trace("Unable to load requested document.");
}//定义各种情况的回调函数
function configureListeners(dispatcher:IEventDispatcher):void {dispatcher.addEventListener(Event.COMPLETE, completeHandler);dispatcher.addEventListener(Event.OPEN, openHandler);dispatcher.addEventListener(ProgressEvent.PROGRESS, progressHandler);dispatcher.addEventListener(SecurityErrorEvent.SECURITY_ERROR, securityErrorHandler);dispatcher.addEventListener(HTTPStatusEvent.HTTP_STATUS, httpStatusHandler);dispatcher.addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler);
}//加载完成时，将触发
function completeHandler(event:Event):void {var loader:URLLoader=URLLoader(event.target);trace("completeHandler: " + loader.data);lblReceive.text = loader.data; //本例中，服务端返回： msg=Hello World&Method=GET&q=菩提树下的杨过var vars:URLVariables=new URLVariables(loader.data);trace("The Method is " + vars.Method); //服务端返回的字符串中如果有 Method=xxx 这样的字符，则Flash中可以直接用vars.Method进行访问
}//刚开始请求时，将触发
function openHandler(event:Event):void {trace("openHandler: " + event);
}//下载进度发生变化时，将触发(可利用这个做加载进度条)
function progressHandler(event:ProgressEvent):void {trace("progressHandler loaded:" + event.bytesLoaded + " total: " + event.bytesTotal);
}//因安全原因出现错误时，将触发
function securityErrorHandler(event:SecurityErrorEvent):void {trace("securityErrorHandler: " + event);
}//http请求状态变化时，将触发
function httpStatusHandler(event:HTTPStatusEvent):void {trace("httpStatusHandler: " + event);
}//io错误时，将触发
function ioErrorHandler(event:IOErrorEvent):void {trace("ioErrorHandler: " + event);
}

服务端FlashHander.ashx可以这样处理：
注意：返回的字符串格式为 name1=value1&name2=value2&name3=value3... 如果name和value中本身包含"="与"&"，请注意用其它字符替换掉

/// 
/// Summary description for FlashHander
/// 
public class FlashHander : IHttpHandler
{public void ProcessRequest(HttpContext context){context.Response.ContentType = "text/plain";context.Response.Write("msg=Hello World&Method=" + context.Request.HttpMethod + "&q=" + context.Request["q"]);}public bool IsReusable{get{return false;}}
}