Android 警告对话框 AlertDialog

    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);         button = (Button) findViewById(R.id.button);         button.setOnClickListener(new View.OnClickListener() {             @Override            public void onClick(View v) {                // TODO Auto-generated method stub                 AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);                 builder.setTitle("提示");                 builder.setIcon(R.drawable.a1);                 builder.setMessage("确定要删除吗？");                 builder.setPositiveButton("确定", new OnClickListener() {                     @Override                    public void onClick(DialogInterface dialog, int which) {                        // TODO Auto-generated method stub                     }                 });                 builder.setNegativeButton("取消", new OnClickListener() {                     @Override                    public void onClick(DialogInterface dialog, int which) {                        // TODO Auto-generated method stub                         dialog.dismiss(); // 取消对话框                    }                 });                 AlertDialog dialog = builder.create();                 dialog.show(); // 显示对话框            }         });     }