为每个操作表按钮添加不同的修饰符

Question

这可能是一个很简单的问题，但我找不到答案。

我正在尝试构建一个带有两个按钮（以及一个取消按钮）的 ActionSheet：

1. “从图库中选择”按钮打开一个imagePicker，其中sourceType 设置为.photoLibrary。
2. “拍一张新照片”按钮打开一个imagePicker，sourceType 设置为.camera。

我已经成功地制作了 ActionSheet 和 imagePicker，但是无法确定在哪里添加修饰符来告诉每个按钮应该使用哪个 sourceType。我设法将它添加到 ActionSheet 之外的 sheet() 修饰符中的普通按钮中，一切正常：

Button(action: {
                            self.show.toggle()
                        })
                        {Text("Take a new picture")}
                        .sheet(isPresented: self.$show, content: {
                            ImagePicker(sourceType: .camera, show: self.$show, image: self.$imageTemp)
                        })

但是，我看不到在 ActionSheet 中的何处包含此信息。非常感谢任何可以提供帮助的人，我希望这很清楚:-)

这是我的代码：

struct ContentView: View {

@State private var showingActionSheet = false
@State var imageTemp : Data = (UIImage(systemName: "photo.on.rectangle.angled")?.jpegData(compressionQuality: 1))!

var body: some View {
        NavigationView {
Image(uiImage: UIImage(data: imageTemp)!)
                        .onTapGesture {
                                        self.showingActionSheet = true
                                    }
                        .actionSheet(isPresented: $showingActionSheet) {
                            ActionSheet(title: Text("Image selector"), message: Text("Select an image"), buttons: [
                                .default(Text("Select from Gallery"))
                                    {
                                        self.show.toggle()
                                    },
                                .default(Text("Take new picture")) {
                                    self.show.toggle()
                                },
                                .cancel()
                            ]
                            )
                        }
                 }
         }
}

而且，以防万一，这是我的 imagePicker 的代码，尽管我认为这可能没有必要。

struct ImagePicker: UIViewControllerRepresentable {
    var sourceType: UIImagePickerController.SourceType = .photoLibrary
    
    @Binding var show: Bool
    @Binding var image: Data
    
    func makeCoordinator() -> ImagePicker.Coordinator {
        let imagePicker = UIImagePickerController()
        return ImagePicker.Coordinator(child1: self)
    }
    
    func makeUIViewController(context: UIViewControllerRepresentableContext<ImagePicker>) -> UIImagePickerController {
        let picker = UIImagePickerController()
        picker.delegate = context.coordinator
        picker.sourceType = sourceType
        return picker
    }

    func updateUIViewController(_ uiViewController: UIImagePickerController, context: UIViewControllerRepresentableContext<ImagePicker>) {

    }
    
    class Coordinator: NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
        var child : ImagePicker
        init(child1: ImagePicker) {
            child = child1
        }
    
    
    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        self.child.show.toggle()
    }
    
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]) {
        let image = info[.originalImage]as! UIImage
        let data = image.jpegData(compressionQuality: 0.45)
        self.child.image = data!
        self.child.show.toggle()
    }
}
}

Answer 1

您的问题几乎可以归结为“我怎样才能呈现多张纸？”，所以this thread 可能会有所帮助。

1. 定义一个新的enum 以包含可能的工作表类型（图库/拍照）
2. 声明一个@State 属性来保存当前的工作表类型。它是可选的，因为当它为 nil 时，将不会显示任何工作表。
3. 将属性设置为您想要的类型
4. 使用sheet(item:onDismiss:content:) 而不是sheet(isPresented:onDismiss:content:)。 isPresented 最适合静态表。 item 适用于您有多种工作表类型时，这是您想要的。

enum PhotoSheetType: Identifiable { /// 1.
    var id: UUID {
        UUID()
    }
    case gallery
    case picture
}

struct ContentView: View {
    
    /// 2.
    @State private var showingType: PhotoSheetType?
    @State private var showingActionSheet = false
    @State var imageTemp : Data = (UIImage(systemName: "photo.on.rectangle.angled")?.jpegData(compressionQuality: 1))!
    
    var body: some View {
        NavigationView {
            Image(uiImage: UIImage(data: imageTemp)!)
                .onTapGesture {
                    self.showingActionSheet = true
                }
                .actionSheet(isPresented: $showingActionSheet) {
                    ActionSheet(
                        title: Text("Image selector"),
                        message: Text("Select an image"),
                        buttons: [
                            .default(Text("Select from Gallery")) {
                                showingType = .gallery /// 3.
                            },
                            .default(Text("Take new picture")) {
                                showingType = .picture /// 3.
                            },
                            .cancel()
                        ]
                    )
                }            /// 4.
                .sheet(item: $showingType) { type in 
                    if type == .gallery {
                        ImagePicker(sourceType: .photoLibrary, showingType: $showingType, image: self.$imageTemp)
                    } else {
                        ImagePicker(sourceType: .camera, showingType: $showingType, image: self.$imageTemp)
                    }
                }
        }
    }
}

您还需要修改您的ImagePicker，以便Binding 接受PhotoSheetType? 而不是Bool。要关闭工作表，只需将 showingType 设置为 nil。

struct ImagePicker: UIViewControllerRepresentable {
    var sourceType: UIImagePickerController.SourceType = .photoLibrary
    
    @Binding var showingType: PhotoSheetType?
    @Binding var image: Data
    
    func makeCoordinator() -> ImagePicker.Coordinator {
        let imagePicker = UIImagePickerController()
        return ImagePicker.Coordinator(child1: self)
    }
    
    func makeUIViewController(context: UIViewControllerRepresentableContext<ImagePicker>) -> UIImagePickerController {
        let picker = UIImagePickerController()
        picker.delegate = context.coordinator
        picker.sourceType = sourceType
        return picker
    }
    
    func updateUIViewController(_ uiViewController: UIImagePickerController, context: UIViewControllerRepresentableContext<ImagePicker>) {
        
    }
    
    class Coordinator: NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
        var child : ImagePicker
        init(child1: ImagePicker) {
            child = child1
        }
        
        
        func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
            self.child.showingType = nil /// set to nil here
        }
        
        func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]) {
            let image = info[.originalImage] as! UIImage
            let data = image.jpegData(compressionQuality: 0.45)
            self.child.image = data!
            self.child.showingType = nil /// set to nil here
        }
    }
}