Android开发解决popupWindow重叠报错问题

ERROR/AndroidRuntime(888): android.view.WindowManager$BadTokenException: Unable to add window -- token android.view.ViewRoot$W@44ef1b68 is not valid; is your activity running? 

public class VerifySuccessDialog extends Toast {
  public VerifySuccessDialog(Context context) {
    super(context);
    //设置toast的View
    setView(LayoutInflater.from(context).inflate(R.layout.include_popwindow_verify, null));
    //弹出位置
    setGravity(Gravity.CENTER, 0, 0);
    //时长
    setDuration(Toast.LENGTH_SHORT);
  }
}

new VerifySuccessDialog(mActivity).show();

<style name="VerifyDialog" parent="@android:style/Theme.Holo.Dialog.NoActionBar">
    <item name="android:windowBackground">@drawable/trans</item>
    <item name="android:windowFrame">@null</item>
    <item name="android:windowIsFloating">true</item>
    <item name="android:backgroundDimEnabled">true</item>
    <item name="android:windowSoftInputMode">adjustPan</item>
  </style>

public class VerifySuccessDialog extends Dialog {
  //用来设置时间自动关闭
  private int showTime;
  public VerifySuccessDialog(Context context) {
    super(context, R.style.VerifyDialog);
    setContentView(R.layout.include_popwindow_verify);
  }
  public int getShowTime() {
    return showTime;
  }
  public void setShowTime(int showTime) {
    this.showTime = showTime;
  }
}

VerifySuccessDialog dialog = new VerifySuccessDialog(mActivity);