Android在按一次退出

private long exitTime = 0; @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(), "再按一次退出应用", Toast.LENGTH_SHORT).show(); exitTime = System.currentTimeMillis(); } else { finish(); System.exit(0); } return true; } return super.onKeyDown(keyCode, event); }

//直接使用，日常工作的使用。

/** * 退出 */

private long mExitTime = 0; private void _exit() { if (System.currentTimeMillis() - mExitTime > 2000) { Toast.makeText(this, "再按一次退出程序", Toast.LENGTH_SHORT).show(); mExitTime = System.currentTimeMillis(); } else { finish(); } }