Android 弹出对话框

new AlertDialog.Builder(com.example.tianhe.MainActivity.this).setTitle(rxTextString)
.setMessage("Niewei You are Great!")
.setPositiveButton("Niewei", new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub

Toast.makeText(com.example.tianhe.MainActivity.this,
"你的愿望 "+" Niewei "+"已送达耶诞老人信箱", Toast.LENGTH_LONG).show();
}
}).show();