Question

   final ProgressDialog Pdialog = ProgressDialog.show(SpinnerClass.this, "", 
                        "Loading. Please wait...", true);
                Thread ProgressThread = new Thread() {
                    @Override
                    public void run() {
                        try {
                                     sleep(3000);   
                                     Pdialog.dismiss();

                        } catch(InterruptedException e) {
                            // do nothing
                        } finally {

                        }
                    }
                };
                ProgressThread.start();
                TabHost1 TabHost1Object2 = new TabHost1();
                TabHost1Object2.tabHost.setCurrentTab(2);

我对此主题的问题是它在进度对话框启动之前设置了当前选项卡。我做错了什么？我希望对话框运行和解除，并在线程完成后设置选项卡。

Answer 1

使用AsyncTask来实现此目标

一些提示：

public class BackgroundAsyncTask extends  AsyncTask<Void, Integer, Void> {  
    int myProgress;
    @Override
    protected void onPostExecute(Void result) {
    TabHost1 tab = new TabHost1();
    tab.tabHost.setCurrentTab(2);
    progressBar.dismiss();

    }
    @Override
    protected Void doInBackground(Void... params) {   
        while(myProgress<100){
            myProgress++;
            publishProgress(myProgress);
            SystemClock.sleep(100);
        }
        return null;
    }

    @Override
    protected void onProgressUpdate(Integer p) {   
        progressBar.setProgress(p);
    }

}

Answer 2

问题是，您正在启动一个不会影响主UI的线程。所以最终会发生的是，你的线程将单独运行，现在允许执行代码的下一行。所以在你的情况下，

            TabHost1 TabHost1Object2 = new TabHost1();
            TabHost1Object2.tabHost.setCurrentTab(2);

这些行将被执行，而不管您的线程是否同时执行。所以你可以在这里做的是你可以去AsyncTask或创建处理程序来处理这部分代码。你必须像这样更改你的代码。

在 onCreate（）

中执行此操作

           Handler handler;
    handler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            if (msg.what == 0) {
         Pdialog.dismiss();     
             TabHost1 TabHost1Object2 = new TabHost1();
            TabHost1Object2.tabHost.setCurrentTab(2);

         }
       };

现在在你的线程中，像这样调用处理程序，

  final ProgressDialog Pdialog = ProgressDialog.show(SpinnerClass.this, "", 
                    "Loading. Please wait...", true);
            Thread ProgressThread = new Thread() {
                @Override
                public void run() {
                    try {
                                 sleep(3000);   


                    } catch(InterruptedException e) {
                        // do nothing
                    } finally {

                             handler.sendEmptyMessage(0);
                    }
                }
            };
this will allow your tabhost to wait until the thread gets executed and will come into view after thread finishes execution.

Android：带有progressBar和setcurrentTab的线程

2 个答案: