安卓：ProgressDialog不显示 [英] Android: ProgressDialog doesn't show

问题描述

我试图创建一个ProgressDialog为Android的应用程序（只需一个简单的显示出的东西正在发生的事情，没有任何按键或任何用户），但我无法得到它的权利。我已经通过论坛和教程，以及对样品 - code自带的SDK，但无济于事。

I'm trying to create a ProgressDialog for an Android-App (just a simple one showing the user that stuff is happening, no buttons or anything) but I can't get it right. I've been through forums and tutorials as well as the Sample-Code that comes with the SDK, but to no avail.

这是我得到了什么：

    btnSubmit.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        (...)
          ProgressDialog pd = new ProgressDialog(MyApp.this);
          pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
          pd.setMessage("Working...");
          pd.setIndeterminate(true);
          pd.setCancelable(false);

          // now fetch the results
          (...long time calculations here...)

          // remove progress dialog
          pd.dismiss();

我也尝试添加 pd.show（）; 和混乱与周围的参数新ProgressDialog 导致什么都没有（除了选择的参数将无法正常工作的错误），这意味着：在ProgressDialog永远不会出现。该应用程序只是继续运行，就好像我从来没有加入该对话框。

I've also tried adding pd.show(); and messed around with the parameter in new ProgressDialog resulting in nothing at all (except errors that the chosen parameter won't work), meaning: the ProgressDialog won't ever show up. The app just keeps running as if I never added the dialog.

我不知道如果我在正确的地方创建对话框，我把它绕了一下但也didnt't帮助。也许我在错误的环境？上述code是在私人的ViewGroup _createInputForm（）在的MyApp 。

I don't know if I'm creating the dialog at the right place, I moved it around a bit but that, too, didnt't help. Maybe I'm in the wrong context? The above code is inside private ViewGroup _createInputForm() in MyApp.

任何暗示是AP preciated，

Any hint is appreciated,

推荐答案

您必须调用pd.show长计算开始前，然后计算必须在一个单独的线程中运行。一个一旦该线程完成，你必须调用pd.dismiss（）关闭prgoress对话框。

you have to call pd.show before the long calculation starts and then the calculation has to run in a separate thread. A soon as this thread is finished, you have to call pd.dismiss() to close the prgoress dialog.

在这里你可以看到一个例子：

here you can see an example:

在progressdialog创建并显示与一个线程调用运行一个沉重的计算：

the progressdialog is created and displayed and a thread is called to run a heavy calculation:

@Override
    public void onClick(View v) {
       pd = ProgressDialog.show(lexs, "Search", "Searching...", true, false);
       Search search = new Search(   ...   );
       SearchThread searchThread = new SearchThread(search);
       searchThread.start();
    }

和这里的主题：

private class SearchThread extends Thread {

        private Search search;

        public SearchThread(Search search) {
            this.search = search;
        }

        @Override
        public void run() {         
            search.search();
            handler.sendEmptyMessage(0);
        }

        private Handler handler = new Handler() {

            @Override
            public void handleMessage(Message msg) {
                displaySearchResults(search);
                pd.dismiss();
            }
        };
    }

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