下面是几种重写返回键 的方法
//第一种public boolean onKeyDown(int keyCode, KeyEvent event) {// 按下键盘上返回按钮 if (keyCode == KeyEvent.KEYCODE_BACK) { new AlertDialog.Builder(this) .setMessage("确定退出系统吗？") .setNegativeButton("取消", new DialogInterface.OnClickListener() {public void onClick(DialogInterface dialog,int which) { } }) .setPositiveButton("确定", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog,int whichButton) {finish(); } }).show(); return true; } else { return super.onKeyDown(keyCode, event);} } //直接退出程序@Override protected void onDestroy() { super.onDestroy(); // 或者下面这种方式 //System.exit(0); //建议用这种 android.os.Process.killProcess(android.os.Process.myPid());}//第二种@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {//TODO somethingreturn true;}return super.onKeyDown(keyCode, event);}//第三种@Overridepublic void onBackPressed() {//TODO somethingsuper.onBackPressed();}
