blocks|key|2141348|text|我假设你的上传图像功能看起来像提斯|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2141349|func+uploadImage(image:+UIImage)+async+->+URL+{+
+++//+some+logic
}|code-block|syntax|javascript|2141350|您希望使许多上传图像任务并行运行，并等待所有上传任务完成。所以我觉得你可以|2141351|Task+{
++++submitButton.isEnable+=+false
++++async+let+firstImage+=+uploadImage(image:+image1)
++++async+let+secondImage+=+uploadImage(image:+image2)
++++async+let+thirdImage+=+uploadImage(image:+image3)
++++let+images+=+await+[firstImage,+secondImage,+thirdImage]
++++submitButton.isEnable+=+true
}|2141352|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I assuming your upload image function look like thís
<pre><code>func uploadImage(image: UIImage) async -&gt; URL { 
 // some logic
}
</code></pre>
And you want to make many upload image task running in parallel and wait to all upload task to be done. So i think you can do something like
<pre><code>Task {
 submitButton.isEnable = false
 async let firstImage = uploadImage(image: image1)
 async let secondImage = uploadImage(image: image2)
 async let thirdImage = uploadImage(image: image3)
 let images = await [firstImage, secondImage, thirdImage]
 submitButton.isEnable = true
}
</code></pre>

blocks|key|2141395|text|如何在您的类中创建一个字典[URL:+UIImage]来保持上传的状态(因此，在启动/完成每个上传时添加/删除)，并且只有当提交按钮为空时才启用提交按钮？不过，请考虑将其封装到一个具有线程安全实现的类中。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2141396|编辑:如果不能禁用按钮，您可以执行如下操作：|2141397|import+SwiftUI
import+Combine

struct+ContentView:+View+{
++++let+viewModel+=+ViewModel()
++++
++++var+body:+some+View+{
++++++++VStack+{
++++++++++++Button+{
++++++++++++++++self.viewModel.upload(url:+URL(string:+"https://google.com?id=\(UUID().uuidString)")!,+image:+UIImage())
++++++++++++++++self.viewModel.upload(url:+URL(string:+"https://google.com?id=\(UUID().uuidString)")!,+image:+UIImage())
++++++++++++}
++++++++++++label:+{
++++++++++++++++Rectangle()
++++++++++++++++++++.fill(Color.red)
++++++++++++}
++++++++++++
++++++++++++Button+{
++++++++++++++++self.viewModel.submit()
++++++++++++}
++++++++++++label:+{
++++++++++++++++Rectangle()
++++++++++++++++++++.fill(Color.blue)
++++++++++++}
++++++++}
++++++++.padding()
++++}
}

class+ViewModel:+ObservableObject+{
++++var+uploadRequests+=+[URL:+UIImage]()
++++var+submitting+=+false
++++
++++let+requestPublisher+=+PassthroughSubject<Bool,+Never>()
++++var+cancellable:+AnyCancellable?
++++
++++init()+{
++++++++self.cancellable+=+requestPublisher.filter+{+[weak+self]+_+in
++++++++++++self?.submitting+??+false
++++++++}.sink+{+[weak+self]+_+in
++++++++++++self?.uploadToServer()
++++++++}
++++}
++++
++++func+upload(url:+URL,+image:+UIImage)+{
++++++++Task+{
++++++++++++print("Uploading+image")
++++++++++++
++++++++++++self.uploadRequests[url]+=+image
++++++++++++
++++++++++++try+await+Task.sleep(nanoseconds:+1_000_000_000)
++++++++++++
++++++++++++self.uploadRequests[url]+=+nil
++++++++++++
++++++++++++print("Image+uploaded")
++++++++++++
++++++++++++//+If+submit+button+was+pressed+meanwhile...
++++++++++++if+self.uploadRequests.count+==+0+{
++++++++++++++++self.requestPublisher.send(true)
++++++++++++}
++++++++}
++++}
++++
++++func+submit()+{
++++++++self.submitting+=+true
++++++++
++++++++guard+self.uploadRequests.count+==+0+else+{
++++++++++++print("Still+ongoing+requests")
++++++++++++return
++++++++}
++++++++
++++++++self.uploadToServer()
++++}
++++
++++func+uploadToServer()+{
++++++++Task+{+[weak+self]+in
++++++++++++guard+let+self+=+self+else+{+return+}
++++++++++++
++++++++++++print("Uploading+to+server")
++++++++++++
++++++++++++self.submitting+=+false
++++++++}
++++}
}|code-block|syntax|javascript|2141398|entityMap^0|D|E|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|R|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|S|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|N|$]]

What about creating a dictionary <code>[URL: UIImage]</code> in your class to keep the state of the uploads (so add/remove when starting/finishing each) and enable your submit button only when that is empty? Do mind wrapping it into a class with a thread-safe implementation though.
EDIT: If the button can't be disabled, you could do something like below:
<pre class="lang-swift prettyprint-override"><code>import SwiftUI
import Combine

struct ContentView: View {
 let viewModel = ViewModel()
 
 var body: some View {
 VStack {
 Button {
 self.viewModel.upload(url: URL(string: &quot;https://google.com?id=\(UUID().uuidString)&quot;)!, image: UIImage())
 self.viewModel.upload(url: URL(string: &quot;https://google.com?id=\(UUID().uuidString)&quot;)!, image: UIImage())
 }
 label: {
 Rectangle()
 .fill(Color.red)
 }
 
 Button {
 self.viewModel.submit()
 }
 label: {
 Rectangle()
 .fill(Color.blue)
 }
 }
 .padding()
 }
}

class ViewModel: ObservableObject {
 var uploadRequests = [URL: UIImage]()
 var submitting = false
 
 let requestPublisher = PassthroughSubject&lt;Bool, Never&gt;()
 var cancellable: AnyCancellable?
 
 init() {
 self.cancellable = requestPublisher.filter { [weak self] _ in
 self?.submitting ?? false
 }.sink { [weak self] _ in
 self?.uploadToServer()
 }
 }
 
 func upload(url: URL, image: UIImage) {
 Task {
 print(&quot;Uploading image&quot;)
 
 self.uploadRequests[url] = image
 
 try await Task.sleep(nanoseconds: 1_000_000_000)
 
 self.uploadRequests[url] = nil
 
 print(&quot;Image uploaded&quot;)
 
 // If submit button was pressed meanwhile...
 if self.uploadRequests.count == 0 {
 self.requestPublisher.send(true)
 }
 }
 }
 
 func submit() {
 self.submitting = true
 
 guard self.uploadRequests.count == 0 else {
 print(&quot;Still ongoing requests&quot;)
 return
 }
 
 self.uploadToServer()
 }
 
 func uploadToServer() {
 Task { [weak self] in
 guard let self = self else { return }
 
 print(&quot;Uploading to server&quot;)
 
 self.submitting = false
 }
 }
}
</code></pre>

In view controller, user can select images, then app will upload to server.
User can select multiples images at one, and can select multiple times.
Each image uploaded will returns an URL to download later.
There is a Submit button to save other info and URLs of uploaded images to server.
I want when user press Submit button, app will wait for all images uploaded (returns URL or throws an error).
I'm using await Taskgroup to upload images in parallel each time user select images.
Is there any way to wait for uploading tasks finish other than using sleep()?
Update:
My code to upload images:
<pre><code>let urls = try await upload(images: images, urls: urls)

func upload(images: [UIImage], urls: [String]) async throws -&gt; [String] {
 try await withThrowingTaskGroup(of: String.self, returning: [String].self) { group in
 for (index, image) in images.enumerated() {
 group.addTask { [self] in
 guard let url = try? await upload(image: image, to: urls[index]) else {
 return &quot;&quot;
 }
 return url
 }
 }
 
 var downloadURLs = [String]()
 
 for try await result in group {
 if result != &quot;&quot; {
 downloadURLs.append(result)
 }
 }
 
 return downloadURLs
 }
}
</code></pre>
Uploading images and submitting data is 2 difference actions:
<ul>
<li>User select images, after that app will upload them automatically.</li>
<li>User can tap Submit button whenever they like, even when images being uploaded, app has to wait for uploading task finish before submit other data.</li>
</ul>

Swift synchronous function waiting for asynchronous functions to finish

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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