Question

我想寻找我的GPS信号，而它正在寻找它我有一个ProgressDialog，但它显示任务完成时：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    requestWindowFeature(Window.FEATURE_NO_TITLE);

    DialogInterface.OnCancelListener dialogCancel = new DialogInterface.OnCancelListener() {

        public void onCancel(DialogInterface dialog) {
            Toast.makeText(getBaseContext(), 
                    "no encotnrada", 
                    Toast.LENGTH_LONG).show();
           // handler.sendEmptyMessage(0);
        }

    };

    pd = ProgressDialog.show(this, "buscando", "gps", true, true, dialogCancel);

    while(currentLocation == null){

    }

    Thread thread = new Thread(this);
thread.start();
}

在run（）中我查找currentLocation值。

我如何等待此信号才能显示对话框？

提前谢谢

Answer 1

最后显示，因为你在主线程中循环。相反，你应该在asynctask或另一个线程中进行等待 - 然后将显示对话框。在asynctask的onPostExecute中，您可以启动另一个线程。

尝试这样的事情：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    requestWindowFeature(Window.FEATURE_NO_TITLE);

    final WaitForIt waiter = new WaitForIt();

    DialogInterface.OnCancelListener dialogCancel = new DialogInterface.OnCancelListener() {

        public void onCancel(DialogInterface dialog) {
            Toast.makeText(getBaseContext(), 
                    "no encotnrada", 
                    Toast.LENGTH_LONG).show();
            waiter.cancelWait();
        }

    };

    pd = ProgressDialog.show(this, "buscando", "gps", true, true, dialogCancel);

    waiter.execute();
}

private class WaitForIt extends AsyncTask<Void, Void, Void> {
     private synchronized boolean cancelled = false;
     public void cancelWait() { cancelled = true; }

     protected Void doInBackground() {
         while(!cancelled) {
             if (gps signal available)
                 break;
         }
     }

     protected void onPostExecute() {
         pd.dismiss();
         Thread thread = new Thread(MyActivity.this);
         thread.start();
     }
}

Answer 2

我已经使用了GPS，并且GPS进程没有运行与运行应用程序相同的进程。所以代码一定有问题，如果找到信号，GPS listener会触发location个对象，因此您可dismiss ProgressDialog。

progressDialog并等待信号

2 个答案: