安卓屏蔽返回键

       安卓屏蔽返回键，弹出提示框，确认或取消

//屏蔽返回键
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if(keyCode == KeyEvent.KEYCODE_BACK){
        //TODO
        //return false;
        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
        builder.setTitle("提示");
        builder.setIcon(android.R.drawable.ic_dialog_info);
        builder.setMessage("确定退出？");
        builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                Intent intent = new Intent(Intent.ACTION_MAIN);
                intent.addCategory(Intent.CATEGORY_HOME);
                intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(intent);
                android.os.Process.killProcess(android.os.Process.myPid());
            }
        });
        builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
            }
        });
        builder.create().show();
    }
    return false;
}

待续。。。