有时候需要在显示UI的时候不中断原来的Activity
比如在播放视频时或者玩游戏时，需要显示某个菜单(可以是系统提示，或类似于TV菜单)
显然用Activity来做是不行的，因为新Activity启动的时候会把原来的Activity pause掉
怎么做呢，可以参考系统电量提示窗口或statusbar那样在service中启动窗口
新窗口将会出现在UI最上层，但不会中断原来的Activity
效果图，一个是播视频中，一个是玩游戏中:
看一下WindowManager.LayoutParams的两个属性:
intTYPE_SYSTEM_ALERT
Window type: system window, such as low power alert.
intTYPE_SYSTEM_OVERLAYWindow
type: system overlay windows, which need to be displayed on top of everything else.
这两个不错，正是我们想要的，上代码~
Seivece中代码
- private void showSystemDialog() {
- /* create ui */
- View v = View.inflate(mContext, R.layout.main, null);
- AlertDialog.Builder b = new AlertDialog.Builder(mContext);
- b.setView(v);
- d = b.create();
- d.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
- //d.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY);
- d.show();
- /* set size & pos */
- WindowManager.LayoutParams lp = d.getWindow().getAttributes();
- WindowManager wm = (WindowManager) getSystemService(WINDOW_SERVICE);
- Display display = wm.getDefaultDisplay();
- if (display.getHeight() > display.getWidth()) {
- //lp.height = (int) (display.getHeight() * 0.5);
- lp.width = (int) (display.getWidth() * 1.0);
- } else {
- //lp.height = (int) (display.getHeight() * 0.75);
- lp.width = (int) (display.getWidth() * 0.5);
- }
- d.getWindow().setAttributes(lp);
- /* update ui data */
- lv = (ListView) d.getWindow().findViewById(R.id.listview);
- SimpleAdapter