mainactivity返回桌面代码：

activity下添加如下代码即可:

@Override
public void onBackPressed() {Intent home = new Intent(Intent.ACTION_MAIN);home.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);home.addCategory(Intent.CATEGORY_HOME);startActivity(home);}

取消返回键返回事件：

activity下添加如下代码即可:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {if (keyCode == KeyEvent.KEYCODE_BACK&& event.getAction() == KeyEvent.ACTION_DOWN) {return true;}return super.onKeyDown(keyCode, event);}

 

再按一次退出程序

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {if (keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN) {if ((System.currentTimeMillis() - exitTime) > 2000) {Toast.makeText(getApplicationContext(), "再按一次返回桌面", Toast.LENGTH_SHORT).show();exitTime = System.currentTimeMillis();} else {Intent home = new Intent(Intent.ACTION_MAIN);home.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);home.addCategory(Intent.CATEGORY_HOME);startActivity(home);}return true;}return super.onKeyDown(keyCode, event);
}private long exitTime = 0;

 

双击事件：

 

    @Override//双击public boolean onTouchEvent(MotionEvent event) {switch (event.getAction()) {case MotionEvent.ACTION_DOWN:long current_time = System.currentTimeMillis();long d_time = current_time - last_time;
//                System.out.println(d_time);if (d_time < 300) {last_time = current_time;Log.i("lgq","双击了----"+last_time);return true;} else {last_time = current_time;}break;}return super.onTouchEvent(event);}