android - 未显示主要 Activity 的 onCreate 中的进度对话框

Question

启动画面后，大约需要 6 秒才能在 Main Activity 中加载 onCreate 内容。所以我想在加载时显示一个进度对话框，这就是我所做的:

import ...

private ProgressDialog mainProgress;

public void onCreate(Bundle davedInstanceState){
    super.onCreate(savedInstanceState);

    setContentView(R.layout.main);

    mProgress = new ProgressDialog (Main.this);
    mProgress.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
    mProgress.setMessage("Loading... please wait");
    mProgress.setIndeterminate(false);
    mProgress.setMax(100);
    mProgress.setProgress(0);
    mProgress.show();

    ---some code---

    mProgress.setProgress(50);

    ---some code---

    mProgress.setProgress(100);
    mProgress.dismiss();
}

它不起作用...屏幕保持黑色 5-6 秒，然后加载主布局。我不知道我哪里做错了:*(

Answer 1

您需要在其他线程(而不是 UI 线程)中启动您繁忙的代码。
在您的 Activity 中创建 ProgressDialog 并在线程中关闭它

mProgress = new ProgressDialog (Main.this);

Runnable runnable = new Runnable() {
    @Override
    public void run() {
        // code that needs 6 seconds for execution

        // after finishing, close the progress bar
        mProgress.dismiss();
    }
};

new Thread(runnable).start();