Android:使用 "progress"GUI 在后台线程中从 Web 加载数据？

Question

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Answer 1

流程的基本思路是创建一个Thread来处理web请求，然后使用Handler和Runnable来管理UI 交互。

我在我的应用程序中管理它的方式是使用一个包含所有智能和业务规则的自定义类来管理我的通信。它还在构造函数中包含变量以允许调用 UI 线程。

这是一个例子:

public class ThreadedRequest
{
    private String url;
    private Handler mHandler;
    private Runnable pRunnable;
    private String data;
    private int stausCode;

    public ThreadedRequest(String newUrl, String newData)
    {
        url = newUrl;
        data = newData;
        mHandler = new Handler();
    }

    public void start(Runnable newRun)
    {
        pRunnable = newRun;
        processRequest.start();
    }

    private Thread processRequest = new Thread()
    {
        public void run()
        {
            //Do you request here...
            if (pRunnable == null || mHandler == null) return;
            mHandler.post(pRunnable);
        }
    }
}

这将从您的 UI 线程调用，如下所示:

final ThreadedRequest tReq = new ThreadedRequest(url, maybeData);
//This method would start the animation/notification that a request is happening
StartLoading();
tReq.start(new Runnable() 
    {
        public void run() 
        {
           //This would stop whatever the other method started and let the user know
           StopLoading();
        }
    });