protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);//先给Activity注册界面进度条功能     setContentView(R.layout.main);     setProgressBarIndeterminateVisibility(true);//在需要显示进度条的时候调用这个方法     setProgressBarIndeterminateVisibility(false);//在不需要显示进度条的时候调用这个方法 }