SwiftUI：发送电子邮件

时间：2019-06-27 05:53:13

标签： swift mfmailcomposeviewcontroller swiftui messageui

在Swift的普通UIViewController中，我使用此代码发送邮件。

let mailComposeViewController = configuredMailComposeViewController()

mailComposeViewController.navigationItem.leftBarButtonItem?.style = .plain
mailComposeViewController.navigationItem.rightBarButtonItem?.style = .plain
mailComposeViewController.navigationBar.tintColor = UIColor.white

if MFMailComposeViewController.canSendMail() {
    self.present(mailComposeViewController, animated: true, completion: nil)
} else {
    self.showSendMailErrorAlert()
}

如何在SwiftUI中实现相同目标？

我需要使用UIViewControllerRepresentable吗？

10 个答案:

答案 0 :(得分：18)

答案正确，是霍布斯大帝和Matteo

在注释中，如果按钮或点击手势上没有设置电子邮件，则需要显示警报

@State var isShowingMailView = false
@State var alertNoMail = false


HStack {
                Image(systemName: "envelope.circle").imageScale(.large)
                Text("Contact")
            }.onTapGesture {
                MFMailComposeViewController.canSendMail() ? self.isShowingMailView.toggle() : self.alertNoMail.toggle()
            }
                //            .disabled(!MFMailComposeViewController.canSendMail())
                .sheet(isPresented: $isShowingMailView) {
                    MailView(result: self.$result)
            }
            .alert(isPresented: self.$alertNoMail) {
                Alert(title: Text("NO MAIL SETUP"))
            }

要预先填充“收件人，身体...” 

func makeUIViewController(context: UIViewControllerRepresentableContext<MailView>) -> MFMailComposeViewController {
        let vc = MFMailComposeViewController()
        vc.setToRecipients(["your@mail.com"])
        vc.setMessageBody("<p>You're so awesome!</p>", isHTML: true)
        vc.mailComposeDelegate = context.coordinator
        return vc
    }

答案 1 :(得分：5)

Yeeee @Hobbes The Tige的回答很好，但是...

让它变得更好！如果用户没有邮件应用（如我没有）怎么办。您可以尝试其他邮件应用程序来处理它。

if MFMailComposeViewController.canSendMail() {
   self.showMailView.toggle()
} else if let emailUrl = Utils.createEmailUrl(subject: "Yo, sup?", body: "hot dog") {
   UIApplication.shared.open(emailUrl)
} else {
   self.alertNoMail.toggle()
}

createEmailUrl 

static func createEmailUrl(subject: String, body: String) -> URL? {
        let to = YOUR_EMAIL
        let subjectEncoded = subject.addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)!
        let bodyEncoded = body.addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)!

        let gmailUrl = URL(string: "googlegmail://co?to=\(to)&subject=\(subjectEncoded)&body=\(bodyEncoded)")
        let outlookUrl = URL(string: "ms-outlook://compose?to=\(to)&subject=\(subjectEncoded)")
        let yahooMail = URL(string: "ymail://mail/compose?to=\(to)&subject=\(subjectEncoded)&body=\(bodyEncoded)")
        let sparkUrl = URL(string: "readdle-spark://compose?recipient=\(to)&subject=\(subjectEncoded)&body=\(bodyEncoded)")
        let defaultUrl = URL(string: "mailto:\(to)?subject=\(subjectEncoded)&body=\(bodyEncoded)")

        if let gmailUrl = gmailUrl, UIApplication.shared.canOpenURL(gmailUrl) {
            return gmailUrl
        } else if let outlookUrl = outlookUrl, UIApplication.shared.canOpenURL(outlookUrl) {
            return outlookUrl
        } else if let yahooMail = yahooMail, UIApplication.shared.canOpenURL(yahooMail) {
            return yahooMail
        } else if let sparkUrl = sparkUrl, UIApplication.shared.canOpenURL(sparkUrl) {
            return sparkUrl
        }

        return defaultUrl
    }

Info.plist 

<key>LSApplicationQueriesSchemes</key>
<array>
    <string>googlegmail</string>
    <string>ms-outlook</string>
    <string>readdle-spark</string>
    <string>ymail</string>
</array>

答案 2 :(得分：4)

我升级并简化了@Mahmud Assan 对新 SwiftUI 生命周期的回答。

import Foundation
import MessageUI

class EmailService: NSObject, MFMailComposeViewControllerDelegate {
public static let shared = EmailService()

func sendEmail(subject:String, body:String, to:String, completion: @escaping (Bool) -> Void){
 if MFMailComposeViewController.canSendMail(){
    let picker = MFMailComposeViewController()
    picker.setSubject(subject)
    picker.setMessageBody(body, isHTML: true)
    picker.setToRecipients([to])
    picker.mailComposeDelegate = self
    
   UIApplication.shared.windows.first?.rootViewController?.present(picker,  animated: true, completion: nil)
}
  completion(MFMailComposeViewController.canSendMail())
}

func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
    controller.dismiss(animated: true, completion: nil)
     }
}

用法：

Button(action: {
            EmailService.shared.sendEmail(subject: "hello", body: "this is body", to: "asd@gmail.com") { (isWorked) in
                if !isWorked{ //if mail couldn't be presented
                    // do action
                }
            }
        }, label: {
            Text("Send Email")
        })

答案 3 :(得分：3)

@Matteo的回答很好，但是需要使用演示环境变量。我已经在这里对其进行了更新，并解决了评论中的所有问题。

import SwiftUI
import UIKit
import MessageUI

struct MailView: UIViewControllerRepresentable {

    @Environment(\.presentationMode) var presentation
    @Binding var result: Result<MFMailComposeResult, Error>?

    class Coordinator: NSObject, MFMailComposeViewControllerDelegate {

        @Binding var presentation: PresentationMode
        @Binding var result: Result<MFMailComposeResult, Error>?

        init(presentation: Binding<PresentationMode>,
             result: Binding<Result<MFMailComposeResult, Error>?>) {
            _presentation = presentation
            _result = result
        }

        func mailComposeController(_ controller: MFMailComposeViewController,
                                   didFinishWith result: MFMailComposeResult,
                                   error: Error?) {
            defer {
                $presentation.wrappedValue.dismiss()
            }
            guard error == nil else {
                self.result = .failure(error!)
                return
            }
            self.result = .success(result)
        }
    }

    func makeCoordinator() -> Coordinator {
        return Coordinator(presentation: presentation,
                           result: $result)
    }

    func makeUIViewController(context: UIViewControllerRepresentableContext<MailView>) -> MFMailComposeViewController {
        let vc = MFMailComposeViewController()
        vc.mailComposeDelegate = context.coordinator
        return vc
    }

    func updateUIViewController(_ uiViewController: MFMailComposeViewController,
                                context: UIViewControllerRepresentableContext<MailView>) {

    }
}

用法：

import SwiftUI
import MessageUI

struct ContentView: View {

   @State var result: Result<MFMailComposeResult, Error>? = nil
   @State var isShowingMailView = false

    var body: some View {
        Button(action: {
            self.isShowingMailView.toggle()
        }) {
            Text("Tap Me")
        }
        .disabled(!MFMailComposeViewController.canSendMail())
        .sheet(isPresented: $isShowingMailView) {
            MailView(result: self.$result)
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

答案 4 :(得分：3)

嗯，我有一个旧代码，以这种方式在SwiftUI中使用。属于此类的静态函数基本上位于我的Utilities.swift文件中。但是出于演示目的，我将其移至此处。

另外，为了保留委托并正常工作，我将其用作单例模式。

第1步：创建电子邮件帮助程序类 

import Foundation
import MessageUI

class EmailHelper: NSObject, MFMailComposeViewControllerDelegate {
    public static let shared = EmailHelper()
    private override init() {
        //
    }
    
    func sendEmail(subject:String, body:String, to:String){
        if !MFMailComposeViewController.canSendMail() {
            // Utilities.showErrorBanner(title: "No mail account found", subtitle: "Please setup a mail account")
            return //EXIT
        }
        
        let picker = MFMailComposeViewController()
        
        picker.setSubject(subject)
        picker.setMessageBody(body, isHTML: true)
        picker.setToRecipients([to])
        picker.mailComposeDelegate = self
        
        EmailHelper.getRootViewController()?.present(picker, animated: true, completion: nil)
    }
    
    func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
        EmailHelper.getRootViewController()?.dismiss(animated: true, completion: nil)
    }
    
    static func getRootViewController() -> UIViewController? {
        (UIApplication.shared.connectedScenes.first?.delegate as? SceneDelegate)?.window?.rootViewController
    }
}

第2步：只需在SwiftUI类中以这种方式调用 

Button(action: {
   EmailHelper.shared.sendEmail(subject: "Anything...", body: "", to: "")
 }) {
     Text("Send Email")
 }

我正在基于SwiftUI的项目中使用它。

答案 5 :(得分：2)

我为此创建了一个github repository。只需将其添加到您的项目中，然后像这样使用它即可：

struct ContentView: View {

@State var showMailSheet = false

var body: some View {
    NavigationView {
        Button(action: {
            self.showMailSheet.toggle()
        }) {
            Text("compose")
        }
    }
    .sheet(isPresented: self.$showMailSheet) {
        MailView(isShowing: self.$showMailSheet,
                 resultHandler: {
                    value in
                    switch value {
                    case .success(let result):
                        switch result {
                        case .cancelled:
                            print("cancelled")
                        case .failed:
                            print("failed")
                        case .saved:
                            print("saved")
                        default:
                            print("sent")
                        }
                    case .failure(let error):
                        print("error: \(error.localizedDescription)")
                    }
        },
                 subject: "test Subjet",
                 toRecipients: ["recipient@test.com"],
                 ccRecipients: ["cc@test.com"],
                 bccRecipients: ["bcc@test.com"],
                 messageBody: "works like a charm!",
                 isHtml: false)
        .safe()
        
    }

  }
}

safe()修饰符检查MFMailComposeViewController.canSendMail()是否为false，它会自动消除模态并尝试打开mailto链接。

答案 6 :(得分：1)

如前所述，您需要通过SwiftUI将组件移植到UIViewControllerRepresentable。

这是一个简单的实现：

struct MailView: UIViewControllerRepresentable {

    @Binding var isShowing: Bool
    @Binding var result: Result<MFMailComposeResult, Error>?

    class Coordinator: NSObject, MFMailComposeViewControllerDelegate {

        @Binding var isShowing: Bool
        @Binding var result: Result<MFMailComposeResult, Error>?

        init(isShowing: Binding<Bool>,
             result: Binding<Result<MFMailComposeResult, Error>?>) {
            $isShowing = isShowing
            $result = result
        }

        func mailComposeController(_ controller: MFMailComposeViewController,
                                   didFinishWith result: MFMailComposeResult,
                                   error: Error?) {
            defer {
                isShowing = false
            }
            guard error == nil else {
                self.result = .failure(error!)
                return
            }
            self.result = .success(result)
        }
    }

    func makeCoordinator() -> Coordinator {
        return Coordinator(isShowing: $isShowing,
                           result: $result)
    }

    func makeUIViewController(context: UIViewControllerRepresentableContext<MailView>) -> MFMailComposeViewController {
        let vc = MFMailComposeViewController()
        vc.mailComposeDelegate = context.coordinator
        return vc
    }

    func updateUIViewController(_ uiViewController: MFMailComposeViewController,
                                context: UIViewControllerRepresentableContext<MailView>) {

    }
}

用法：

struct ContentView: View {

    @State var result: Result<MFMailComposeResult, Error>?
    @State var isShowingMailView = false

    var body: some View {
        ZStack {
            VStack {
                Button(action: {
                    self.isShowingMailView.toggle()
                }) {
                    Text("Show mail view")
                }
                if result != nil {
                    Text("Result: \(String(describing: result))")
                    .lineLimit(nil)
                }
            }
            if (isShowingMailView) {
                mailView()
                .transition(.move(edge: .bottom))
                .animation(.basic())
            }
        }


    }

    private func mailView() -> some View {
        MFMailComposeViewController.canSendMail() ?
            AnyView(MailView(isShowing: $isShowingMailView, result: $result)) :
            AnyView(Text("Can't send emails from this device"))
    }
}

注释：

我正在使用ZStack进行演示，因为Modal的行为非常不一致。

（在运行iOS 13的iPhone 7 Plus上进行了测试-像魅惑一样工作）

答案 7 :(得分：1)

我还改进了@Hobbes答案，以轻松配置参数，例如主题，收件人。

Checkout this gist

即使懒得结帐，SPM呢？

您现在可以轻松地在不同项目中复制粘贴此礼物。

用法； 

import SwiftUI
import MessagesUI
// import SwiftUIEKtensions // via SPM

@State private var result: Result<MFMailComposeResult, Error>? = nil
@State private var isShowingMailView = false

var body: some View {
    Form {
        Button(action: {
            if MFMailComposeViewController.canSendMail() {
                self.isShowingMailView.toggle()
            } else {
                print("Can't send emails from this device")
            }
            if result != nil {
                print("Result: \(String(describing: result))")
            }
        }) {
            HStack {
                Image(systemName: "envelope")
                Text("Contact Us")
            }
        }
        // .disabled(!MFMailComposeViewController.canSendMail())
    }
    .sheet(isPresented: $isShowingMailView) {
        MailView(result: $result) { composer in
            composer.setSubject("Secret")
            composer.setToRecipients(["fancy@mail.com"])
        }
    }
}

答案 8 :(得分：1)

不幸的是，@Matteo 的解决方案对我来说并不完美。它看起来有问题:(

替代解决方案

struct MailComposeSheet<T: View>: UIViewControllerRepresentable {
    let view: T

    @Binding var isPresented: Bool

    func makeUIViewController(context: Context) -> UIHostingController<T> {
        UIHostingController(rootView: view)
    }

    func updateUIViewController(_ uiViewController: UIHostingController<T>, context: Context) {
        uiViewController.rootView = view

        if isPresented, uiViewController.presentedViewController == nil {
            let picker = MFMailComposeViewController()

            picker.mailComposeDelegate = context.coordinator
            picker.presentationController?.delegate = context.coordinator

            uiViewController.present(picker, animated: true)
        }
    }

    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }

    class Coordinator: NSObject, MFMailComposeViewControllerDelegate, UIAdaptivePresentationControllerDelegate {
        var parent: MailComposeSheet

        init(_ mailComposeSheet: MailComposeSheet) {
            self.parent = mailComposeSheet
        }

        func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
            controller.dismiss(animated: true) { [weak self] in
                self?.parent.isPresented = false
            }
        }

        func presentationControllerDidDismiss(_ presentationController: UIPresentationController) {
            parent.isPresented = false
        }
    }
}

extension View {
    func mailComposeSheet(isPresented: Binding<Bool>) -> some View {
        MailComposeSheet(
            view: self,
            isPresented: isPresented
        )
    }
}

用法：

struct ContentView: View {
    @State var showEmailComposer = false

    var body: some View {
        Button("Tap me") {
            showEmailComposer = true
        }
        .mailComposeSheet(isPresented: $showEmailComposer)
    }
}

我是 Swift 新手，如果我做错了什么，请告诉我。

答案 9 :(得分：0)

我刚刚写了一篇关于此的小文章。这是另一种选择，可以使用UIKit代替SwiftUI来处理电子邮件。

https://link.medium.com/posgdRBMWX

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