iOS沙盒环境调用分享菜单时出现异常报错

环境信息 #

• Xcode 15.3
• Swift 5.10
• iOS 17.4.1（真机测试）

问题现象 #

点击待办项中的图片打开全屏查看器后，点击底部分享按钮无任何响应，日志输出权限及弹窗冲突类错误，核心错误如下：

Attempt to present <UIActivityViewController: 0x10582e800> on <_TtGC7SwiftUI19UIHostingControllerGVS_15ModifiedContentVS_7AnyViewVS_12RootModifier__: 0x10301e800> (from <_TtGC7SwiftUI19UIHostingControllerGVS_15ModifiedContentVS_7AnyViewVS_12RootModifier__: 0x10301e800>) which is already presenting <_TtGC7SwiftUI29PresentationHostingControllerVS_7AnyView_: 0x10700ee00>.

问题原因 #

代码直接使用rootViewController弹出分享表，但此时rootViewController已经弹出了全屏图片查看器（fullScreenCover），iOS不允许同一控制器同时present两个弹窗，必须在当前最顶层的presented控制器上发起新的present操作。

修复方案 #

方案1：获取顶层控制器弹出分享表 #

添加UIViewController扩展，用于定位当前活跃的最顶层控制器：

extension UIViewController {
    static func topMostViewController() -> UIViewController? {
        let keyWindow = UIApplication.shared.connectedScenes
            .filter { $0.activationState == .foregroundActive }
            .first(where: { $0 is UIWindowScene })
            .flatMap({ $0 as? UIWindowScene })?.windows
            .first(where: { $0.isKeyWindow })
        
        var topController = keyWindow?.rootViewController
        while let presentedViewController = topController?.presentedViewController {
            topController = presentedViewController
        }
        return topController
    }
}

修改shareImage方法，使用顶层控制器弹出分享表：

private func shareImage(_ image: UIImage) {
    let activityController = UIActivityViewController(activityItems: [image], applicationActivities: nil)
    guard let topController = UIViewController.topMostViewController() else { return }
    topController.present(activityController, animated: true, completion: nil)
}

方案2：SwiftUI原生sheet方式（更贴合SwiftUI风格） #

创建UIActivityViewController的SwiftUI包装器：

struct ActivityViewController: UIViewControllerRepresentable {
    var activityItems: [Any]
    var applicationActivities: [UIActivity]? = nil
    
    func makeUIViewController(context: Context) -> UIActivityViewController {
        UIActivityViewController(activityItems: activityItems, applicationActivities: applicationActivities)
    }
    
    func updateUIViewController(_ uiViewController: UIActivityViewController, context: Context) {}
}

在ContentView中添加状态变量控制分享弹窗：

@State private var sharedImage: UIImage? = nil

修改图片查看器内的分享按钮逻辑：

Button(action: {
    sharedImage = uiImage
}) {
    Label("Share", systemImage: "square.and.arrow.up")
        .foregroundColor(.blue)
}
.buttonStyle(.plain)

最后在ContentView的body末尾添加sheet：

.sheet(item: $sharedImage) { image in
    ActivityViewController(activityItems: [image])
}

关键代码片段（方案1示例） #

// 顶层控制器扩展
extension UIViewController {
    static func topMostViewController() -> UIViewController? {
        let keyWindow = UIApplication.shared.connectedScenes
            .filter { $0.activationState == .foregroundActive }
            .first(where: { $0 is UIWindowScene })
            .flatMap({ $0 as? UIWindowScene })?.windows
            .first(where: { $0.isKeyWindow })
        
        var topController = keyWindow?.rootViewController
        while let presentedViewController = topController?.presentedViewController {
            topController = presentedViewController
        }
        return topController
    }
}

struct ContentView: View {
    // 原有状态变量、查询属性保持不变
    
    private func shareImage(_ image: UIImage) {
        let activityController = UIActivityViewController(activityItems: [image], applicationActivities: nil)
        guard let topController = UIViewController.topMostViewController() else { return }
        topController.present(activityController, animated: true, completion: nil)
    }
    
    // 原有视图、方法逻辑保持不变
}

内容的提问来源于stack exchange，提问作者domid