安卓Modal的statusBarTranslucent属性

这个属性开启后可以保持Modal一直在状态栏下，键盘弹出时不会将Modal整体向上推，对于Modal顶部有输入键盘的比较有用。

源码:

/**
   * Returns the view that will be the root view of the dialog. We are wrapping this in a
   * FrameLayout because this is the system's way of notifying us that the dialog size has changed.
   * This has the pleasant side-effect of us not having to preface all Modals with "top:
   * statusBarHeight", since that margin will be included in the FrameLayout.
   */
  private View getContentView() {
    FrameLayout frameLayout = new FrameLayout(getContext());
    frameLayout.addView(mHostView);
    if (mStatusBarTranslucent) {
      frameLayout.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
    } else {
      frameLayout.setFitsSystemWindows(true);
    }
    return frameLayout;
  }

关键代码frameLayout.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN)它能保持Activity在状态栏下全屏显示。