Dialog alertDialog = new AlertDialog.Builder(this)

        .setTitle("标题")

        .setMessage("内容")

        .setIcon(R.drawable.ic_launcher).create();

        alertDialog.show();

public class MainActivity extends Activity {

    okListener oklistener=new okListener();

    noListener nolistener =new noListener();

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.demo);

        Dialog alertDialog = new AlertDialog.Builder(this).setTitle("标题")

                .setMessage("内容").setIcon(R.drawable.ic_launcher)

                .setPositiveButton("确定", oklistener)

                .setNegativeButton("取消", nolistener)

                .create();

        alertDialog.show();

    }

    public class okListener implements DialogInterface.OnClickListener{

        @Override

        public void onClick(DialogInterface dialog, int which) {

            // TODO Auto-generated method stub

        }

    }

    public class noListener implements DialogInterface.OnClickListener{

        @Override

        public void onClick(DialogInterface dialog, int which) {

            // TODO Auto-generated method stub

        }

    }

}