//第一種方法（彈出對話框）@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {// TODO Auto-generated method stubswitch (keyCode) {case KeyEvent.KEYCODE_BACK:AlertDialog.Builder build = new AlertDialog.Builder(this);build.setTitle("系統提示").setMessage("確定要退出嗎？");build.setPositiveButton("確定",new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {finish();}});build.setNegativeButton("取消",new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {}}).show();break;}return super.onKeyDown(keyCode, event);}

//第二種方法（再按一次退出程序）private long exitTime = 0;@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {if (keyCode == KeyEvent.KEYCODE_BACK&& event.getAction() == KeyEvent.ACTION_DOWN) {if ((System.currentTimeMillis() - exitTime) > 2000) {Toast.makeText(getApplicationContext(), "再按一次退出程序",Toast.LENGTH_SHORT).show();exitTime = System.currentTimeMillis();} else {finish();System.exit(0);}return true;}return super.onKeyDown(keyCode, event);}

轉載于:https://www.cnblogs.com/oversea201405/p/3749576.html

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