SwiftUI中能否让PhotosUI PhotosPicker直接调用相机？

核心结论 #

PhotosPicker（PhotosUI框架）不支持直接指定相机作为图片来源，它的设计目标是让用户从系统照片图库中选择内容，没有提供类似UIImagePickerController的sourceType参数来切换相机/图库模式。

可行的解决方案 #

如果你需要相机功能，不用完全放弃PhotosPicker，可以结合以下方式实现：

1. 拆分入口：同时提供图库选择和相机拍摄按钮

保留PhotosPicker处理图库选择，再单独做一个相机按钮，用UIImagePickerController封装成SwiftUI视图（也就是你说的ImagePicker），让用户自主选择操作方式。

示例代码：

// 封装相机的SwiftUI视图
struct CameraPicker: UIViewControllerRepresentable {
    @Binding var image: UIImage?
    @Environment(\.dismiss) var dismiss
    
    func makeUIViewController(context: Context) -> UIImagePickerController {
        let picker = UIImagePickerController()
        picker.sourceType = .camera
        picker.delegate = context.coordinator
        return picker
    }
    
    func updateUIViewController(_ uiViewController: UIImagePickerController, context: Context) {}
    
    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }
    
    class Coordinator: NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
        let parent: CameraPicker
        
        init(_ parent: CameraPicker) {
            self.parent = parent
        }
        
        func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
            if let uiImage = info[.originalImage] as? UIImage {
                parent.image = uiImage
            }
            parent.dismiss()
        }
        
        func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
            parent.dismiss()
        }
    }
}

// 主视图使用示例
struct ContentView: View {
    @State private var showPhotosPicker = false
    @State private var showCameraPicker = false
    @State private var selectedImage: UIImage?
    
    var body: some View {
        VStack {
            selectedImage?
                .resizable()
                .scaledToFit()
                .frame(height: 200)
            
            Button("从图库选择") {
                showPhotosPicker = true
            }
            
            Button("拍摄照片") {
                showCameraPicker = true
            }
        }
        .photosPicker(isPresented: $showPhotosPicker, selection: $selectedImage)
        .sheet(isPresented: $showCameraPicker) {
            CameraPicker(image: $selectedImage)
        }
    }
}

2. 统一入口：自定义选择弹窗

如果希望用户通过一个入口选择图库或相机，可以做一个自定义弹窗，点击后弹出选项菜单，再分别触发对应的选择器。

示例代码片段：

struct ContentView: View {
    @State private var showActionSheet = false
    @State private var showPhotosPicker = false
    @State private var showCameraPicker = false
    @State private var selectedImage: UIImage?
    
    var body: some View {
        VStack {
            selectedImage?
                .resizable()
                .scaledToFit()
                .frame(height: 200)
            
            Button("获取照片") {
                showActionSheet = true
            }
        }
        .actionSheet(isPresented: $showActionSheet) {
            ActionSheet(title: Text("选择方式"), buttons: [
                .default(Text("从图库选择")) {
                    showPhotosPicker = true
                },
                .default(Text("拍摄照片")) {
                    showCameraPicker = true
                },
                .cancel()
            ])
        }
        .photosPicker(isPresented: $showPhotosPicker, selection: $selectedImage)
        .sheet(isPresented: $showCameraPicker) {
            CameraPicker(image: $selectedImage)
        }
    }
}

要不要切换到ImagePicker？ #

如果你的需求只需要相机功能，直接用UIImagePickerController封装的ImagePicker更直接；但如果同时需要图库选择的便捷性（比如PhotosPicker支持多选、Live Photo等特性），建议结合两者使用，兼顾不同场景。

内容的提问来源于stack exchange，提问作者SwiftlySlow