警告对话框

public class MainActivity extends Activity {    private Button button;    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        button = (Button) findViewById(R.id.button1);    }    public void myClick(View view) {        // 创建一个对话框对象        AlertDialog.Builder builder = new Builder(MainActivity.this);        builder.setTitle("约吗？");        // builder.setCancelable(false);//对话框弹出之后不让取消        builder.setIcon(R.drawable.yue);        builder.setMessage("今天是个好日子");        builder.setNegativeButton("不约", new DialogInterface.OnClickListener() {            public void onClick(DialogInterface dialog, int which) {                Toast.makeText(MainActivity.this, "不好意思，我是正经人，不约", 0).show();            }        });        builder.setPositiveButton("约", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialog, int which) {                Toast.makeText(MainActivity.this, "那就一起约吧", 0).show();            }        });        // View view2 = getLayoutInflater().inflate(R.layout.activity_main2,        // null);        // builder.setView(view2);        builder.show();    }    public boolean onCreateOptionsMenu(Menu menu) {        getMenuInflater().inflate(R.menu.main, menu);        return true;    }}