Swiftui macos 扩展委托视图是可能的

Question

我有以下代码，单击该按钮可以让我clone repository 位于github 上。

import SwiftUI
import Git

struct File: View {
    @State var pathUrl = "https://github.com/way-to-code/git-macOS.git"
    @State var nameDir = "/Users/"
    
    func cloneReport() {
        DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
            let url: URL = URL(string: pathUrl)!
            let report = GitRepository(from: url)
            //report.delegate = progressTracker
            do {
                try report.clone(at: nameDir)
            } catch let e {
                print("Errors \(e).")
            }
        }
    }
    
    var body: some View {
        Button(action: {
            cloneReport()
        }) {
            Text("Clone").frame(width: 330)
        }
    }
}

struct File_Previews: PreviewProvider {
    static var previews: some View {
        File()
    }
}

我正在使用以下framework，它告诉我是否要为跟踪事件实现framework 协议的delegate，我必须这样做：

let progressTracker = MyCustomObject()

let repository: GitRepository
repository.delegate = progressTracker

// implement RepositoryDelegate protocol in order to track the events
extension MyCustomObject: RepositoryDelegate {
 func repository(_ repository: Repository, didProgressClone progress: String) {
 }
}

我不能做一个不存在的类的extension 给我以下错误：Cannot find type 'MyCustomObject' in scope

是否可以扩展View 类型的struct？

你能给我一些建议吗？

Answer 1

一个例子，作者说为委托创建或使用 MyCustomObject 类。

您必须创建一个用于跟踪的类。

首先，创建一个与 MyCustomObject 相同的类

class ProgressTracker: RepositoryDelegate {
    func repository(_ repository: Repository, didProgressClone progress: String) {
        print(progress) // Here you will get progress
    }
}

并在视图内部配置

struct File: View {
    @State var pathUrl = "https://github.com/way-to-code/git-macOS.git"
    @State var nameDir = "/Users/"
    
    let progressTracker = ProgressTracker()  // << === Here
    
    func cloneReport() {
        DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
            let url: URL = URL(string: pathUrl)!
            let report = GitRepository(from: url)
            report.delegate = progressTracker // << === Here
            
            do {
                try report.clone(at: nameDir)
            } catch let e {
                print("Errors \(e).")
            }
        }
    }

---

---

如果您希望在文件视图中获得进度，您可以像这样设置您的视图。

struct File: View {
    @State var pathUrl = "https://github.com/way-to-code/git-macOS.git"
    @State var nameDir = "/Users/"
    
    var progressTracker = ProgressTracker()  // << === Here
    
    func cloneReport() {
        DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
            let url: URL = URL(string: pathUrl)!
            let report = GitRepository(from: url)
            report.delegate = progressTracker // << === Here
            
            progressTracker.progressBlock = { progress in // << === Here
                print(progress)
            }
            
            do {
                try report.clone(at: nameDir)
            } catch let e {
                print("Errors \(e).")
            }
        }
    }
    
    var body: some View {
        Button(action: {
            cloneReport()
        }) {
            Text("Clone").frame(width: 330)
        }
    }
}

// implement RepositoryDelegate protocol in order to track the events
class ProgressTracker: RepositoryDelegate {
    lazy var progressBlock: ((String) -> Void)? = nil
    
    func repository(_ repository: Repository, didProgressClone progress: String) {
        self.progressBlock?(progress)
    }
}