ionic使用AlertController报错

提示：

Error: Uncaught (in promise): removeView was not found

Error: Uncaught (in promise): inserted view was already destroyed

  showToast(code) {
    let toast = this.toastCtrl.create(this.mess[code]);
    toast.onDidDismiss(() => {
      console.log('Dismissed toast');
    });
    toast.present();
  }

还没找到原因。。。