我从 https://www.weheartswift.com/firebase-101/ 中获取了原始代码并根据我的需要进行编辑。
在这个 View Controller 中,我更新了一个图像,然后使用一个按钮执行展开转场,另一个 View Controller 调用函数 updateValues 并将数据存储在 firebase 中。
不起作用的是 updateValues 函数,但仅适用于 taskImg 值,其他函数(taskTitle 和 taskLat 和 taskLon 完美运行)
我认为它不会更新,因为它在这个代码块内
#self.storageRef.child(filePath).put(data as Data, metadata: metaData).observe(.success) { (snapshot) in
self.downloadURL = snapshot.metadata!.downloadURL()!.absoluteString
completion()
}
#
因为如果我尝试从内部更改任何 var 的值,它什么也不会发生,在该 block 之外它可以工作,但显然我不能,因为我必须动态生成它...
有人可以帮帮我吗?
func editImage(completion: @escaping callback){
let resizedImage = resizeImage(image: imagePicked.image!, newWidth: 200)
var data = NSData()
// data = UIImageJPEGRepresentation(imagePicked.image!, 0.1)! as NSData
data = UIImageJPEGRepresentation(resizedImage!, 0.1)! as NSData
let filePath = "\(FIRAuth.auth()!.currentUser!.uid)/Pictures/\(NSUUID().uuidString)"
let metaData = FIRStorageMetadata()
//store downloadURL
metaData.contentType = "image/jpg"
self.storageRef.child(filePath).put(data as Data, metadata: metaData).observe(.success) { (snapshot) in
//progress upload
self.storageRef.child(filePath).put(data as Data, metadata: metaData).observe(.progress) { snapshot in
// Upload reported progress
if let progress = snapshot.progress {
let percentComplete = 100.0 * Double(progress.completedUnitCount) / Double(progress.totalUnitCount)
print("percent \(percentComplete)")
}
}
self.storageRef.child(filePath).put(data as Data, metadata: metaData).observe(.success) { snapshot in
// Upload completed successfully
print("success")
}
self.storageRef.child(filePath).put(data as Data, metadata: metaData).observe(.failure) { snapshot in
print(snapshot.error?.localizedDescription ?? "" )
}
self.downloadURL = snapshot.metadata!.downloadURL()!.absoluteString
completion()
print(self.taskImg,"\"inside editImage function, right value")
}
}
func updateValues() {
self.taskTitle = self.titleField.text
if tapped == true {
self.taskLat = latitude
self.taskLon = longitude
}else{
//doesn't update location
}
self.taskCompleted = self.completedSwitch.isOn
if tappedpicture == true {
editImage { self.taskImg = self.downloadURL
print (self.downloadURL,"\"inside updateValues function, right value")
}
print (self.taskImg,"\"this is where i need it and it's wrong value")
}else{
//doesn't update location
}
}
最佳答案
我的猜测是,unwind segue 发生在放置数据操作完成之前,并且 self.downloadURL
未在其他 View Controller 读取时设置。
要检查这一点,您可以在 put 完成 block 中设置一个断点,并在目标 segue 中设置一个断点。
关于swift var 不会在 block 外更新,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/42863584/