public function actionIndex($mid = -1)
 {
     $model = new MembershipForm();
     $model->paiddate = date("Y-m-d ", time());
     $model->mid = $mid;
     $message = "";
     $errormsg = "";
     if ($model->load(Yii::$app->request->post()) && $model->validate()) {
         $message = "保存成功";
         $model->save();
     } else {
         $errormsg = $model->getErrors();
     }
     return $this->render("index", ['model' => $model, 'message' => $message, 'errormsg' => $errormsg]);
 }