Dialog不响应，一直在转

dialog上面一直保持不响应，图片如下：代码如下：
public void testOnStart_stateRunning() throws Exception {
setState(FileTransferService.STATE_RUNNING);

    setIntent(Intent.ACTION_SEND);
    mActivity = getActivity();
    mInstrumentation.waitForIdleSync();

    final Field field
        = SdcardTransferActivity.class.getDeclaredField(FIELD_NAME_PROGRESS_DIALOG);
    field.setAccessible(true);

    mActivity.runOnUiThread(new Runnable() {
        @Override
        public void  run() {
            try {
               // ProgressDialog dialog=new ProgressDialog(this.getActivity);
               ProgressDialog dialog = (ProgressDialog) field.get(mActivity);
                if (dialog != null) {
                    // Tap positive button.
                    Button positive = dialog.getButton(DialogInterface.BUTTON_POSITIVE);
                    positive.performClick();


                }

貌似木有看到你调用关闭dialog的dismiss()方法

后来我加了 dialog.dismiss()了，还是不行啊？问题不知在那？

为什么不用builder