AlertDialog

import android.app.AlertDialog;
import android.content.DialogInterface;

        new AlertDialog.Builder (this)
        .setTitle ("Alerting Message")
        .setMessage ("你好！")
        .setPositiveButton("确定",new DialogInterface.OnClickListener() {  
            @Override
            public void onClick(DialogInterface dialog, int which) {
                //do nothing - it will close on its own
            }
         })