SwiftUI：从环境对象内的函数以编程方式关闭模式表

Question

我有一个显示模式表的主视图。由于我有多个模态，我使用枚举和状态来控制which sheet is presented.

@State var activeSheet: Sheet?

在我的主视图中：

    Button(action: {
        activeSheet = .settings
    }, label: {
        Text(“Button”)
    })

   .sheet(item: $activeSheet) { sheet in
        switch sheet {
        case .info:
          InfoView()
        case .settings:
          SettingsView()
        }
      }

设置视图：

struct SettingsView: View {
    @Environment(\.presentationMode) private var presentationMode
    @EnvironmentObject var model: MainModel
    
    var body: some View {
        Button("Action") {
            model.myFunction()
        }
    }
}

在我的 InfoView 表中，我有一个按钮，可以调用 EnvironmentObject 中的函数。 EnvironmentObject 中的功能完成后如何关闭工作表？

每个视图都链接到同一个 EnvironmentObject 顺便说一句。

谢谢！

Answer 1

根据您部署的最低 iOS 版本，您有两种选择：

如果您的最低 iOS 版本为 InfoView 和 SettingsView 中都使用系统环境 \.presentationMode。

struct SettingsView: View {
    @EnvironmentObject var model: MainModel
    @Environment(\.presentationMode) private var presentationMode

    var body: some View {
        Button("Dismiss") {

            /// ... Do something here prior to dismissing the sheet.
            model.MyFunction(email: email, password: password) {
                presentationMode.wrappedValue.dismiss()
            }
        }
    }
}

在您的最低 iOS 版本为 iOS 15 时，InfoView 和 SettingsView 都使用系统环境 \.dismiss。

struct SettingsView: View {
    @EnvironmentObject var model: MainModel
    @Environment(\.dismiss) private var dismiss

    var body: some View {
        Button("Dismiss") {

            /// ... Do something here prior to dismissing the sheet.
            model.MyFunction(email: email, password: password) {
                dismiss()
            }
        }
    }
}

还有MainModel类：

class MainModel: ObservableObject {
    func myFunction(email: String, password: String, onSuccess: (() -> Void)? = nil) {         
        auth.signIn(withEmail: email, password: password) { [weak self] result, error in
            if result == nil, error != nil {
                 self?.showAlert = true
            } else {
                 guard result != nil, error == nil else { return }
                 /* Success */
                 self?.signedIn = true
                 onSuccess?()
            }
        }
    }
}

替代解决方案：

如果您的最低部署目标是 >= iOS 14，您可以像这样监听环境对象属性的变化：

struct SettingsView: View {
    @EnvironmentObject var model: MainModel
    @Environment(\.dismiss) private var dismiss

    var body: some View {
        Button("Dismiss") {
            model.MyFunction(email: email, password: password)
        }
        .onChange(of: model.signedIn) { signedIn in
            if signedIn {
                dismiss()
            }
        }
    }
}