Question

我正在尝试在Firebase完成其下载/上传（例如segue或刷新）后运行一些代码

例如

我具有x3保存功能，所有功能均具有用于更新某些数据（例如文本和图像）的存储和数据库的代码

save1()
save2()
save3()

当执行IBAction时，我希望这些功能运行，如果它们没有错误，则在运行完成时（segue或刷新）执行这些功能，

这3个保存功能当前在IBAction中起作用

@IBAction func saveTap(_ sender: Any) {

save1()
save2()
save3()

}

保存功能如下：

（我检查图像是否已更改，然后开始上传过程）

 func save1(){

    if image1.image == nil {
        let gender = userGender.text
        self.databaseRef.child("users").child(gender!).child(Auth.auth().currentUser!.uid).child("images").child("imageOne").removeValue { (error, ref) in
            if error != nil {
                print(error!)}
        }
        let imageRef = self.storage.child(Auth.auth().currentUser!.uid).child("image1")
        imageRef.delete { error in
            if let error = error {
                print(error)
            } else {
                print("Photo 1 image deleted")}
        }

    } else {

        //Firebase child references
        let profileImageRef = storage.child(Auth.auth().currentUser!.uid).child("image1")
        let metaData = StorageMetadata()
        metaData.contentType = "image1/jpeg"
        //Firebase child references

        //change uiimageview to uiimage for upload
        guard let image = image1.image else
        {return}
        //change uiimageview to uiimage for upload

        //Send to firebase storage
        profileImageRef.putData(image.jpegData(compressionQuality: 0.1)!, metadata: metaData) { (data, error) in
            if error == nil
            {print("Photo 1 uploaded to storage")}
            else
            {print(error?.localizedDescription as Any)}}
        //Send to firebase storage


        //Update firebase database
        profileImageRef.downloadURL(completion: { (url, error) in
            if error != nil{
                print(error!)
                return}

            if let profilePhotoUrl = url?.absoluteString{
                let newValuesForProfile = profilePhotoUrl
                let gender = self.userGender.text
                self.databaseRef.child("users").child(gender!).child(Auth.auth().currentUser!.uid).child("images").child("imageOne").setValue(newValuesForProfile, withCompletionBlock: { (error, ref) in
                    if error != nil{
                        print(error!)
                        return}
                    print("Photo 1 updated in database")})}})
        //Update firebase database
    }

我需要先完成上传，然后再执行segues，因为下一个视图将刷新到我要上传的已保存数据。

任何帮助都会很棒，已经在这里工作了几个星期：（ iv尝试了完成处理程序，但到目前为止还没有运气。

提前谢谢

Answer 1

我认为dispatchGroup适合您的情况

let dispatchGroup = DispatchGroup()

dispatchGroup.enter()
save1 { dispatchGroup.leave() }

dispatchGroup.enter()
save2 { dispatchGroup.leave() }



dispatchGroup.notify(queue: .main) {
  self.perFormSegue//////
}

//

// e.x结构

func save1(completion:@escaping()->()) {

  firesCallBack {       
   if success {
      completion()
   }
  }
}

Answer 2

您可以像这样检查更改是否用.childChanged保存：

    save1()
    save2()
    save3()

let ref: DatabaseReference!
ref = /YourDirectDatabaseReferenceForTheChangedNode/
ref.observe(.childChanged, with: {(snaphost) -> Void in

    }
})

也许您也应该使用UIActivityIndicatorView来显示背景中正在发生的事情。

@IBAction func saveTap(_ sender: Any) {

           save1()
           save2()
           save3()

        let activity: UIActivityIndicatorView = UIActivityIndicatorView()
            activity.center = self.view.center
            activity.hidesWhenStopped = true
            activity.activityIndicatorViewStyle = .whiteLarge
            self.view.addSubview(activity)

         let ref: DatabaseReference!
         ref = /YourDirectDatabaseReferenceForTheChangedNode/
         ref.observe(.childChanged, with: {(snaphost) -> Void in

           activity.stopAnimating()
           if UIApplication.shared.isIgnoringInteractionEvents {
              UIApplication.shared.endIgnoringInteractionEvents()
           }
        self.performSegue(withIdentifier: "backhome", sender: self)
        }
    })
 }

将/ YourDirectDatabaseReferenceForTheChangedNode /替换为正确的子项（保存后应更改的内容）。

Firebase下载/上传完成后进行Segue

2 个答案: