android 退出时弹出对话框

AlertOnBack

public boolean onKeyDown(int keyCode, KeyEvent event) {
	if(keyCode == KeyEvent.KEYCODE_BACK){
		AlertDialog.Builder builder = new AlertDialog.Builder(this);
		builder.setTitle("程序名称")
			.setCancelable(true)
			.setMessage("确定退出?")
			.setPositiveButton("是的", new DialogInterface.OnClickListener() {
				@Override
				public void onClick(DialogInterface dialog, int which) {
//						System.exit(0);
					getParent().finish();
				}
			})
			.setNegativeButton("取消", new DialogInterface.OnClickListener() {
				@Override
				public void onClick(DialogInterface dialog, int which) {
				}
			})
			.show();
		
	}
	return super.onKeyDown(keyCode, event);
}