将数据从 UIViewControllerRepresentable 传递给 UIViewController

Posted 2023-03-14

【中文标题】将数据从 UIViewControllerRepresentable 传递给 UIViewController

【英文标题】：Passing data from UIViewControllerRepresentable to UIViewController

【发布时间】：2020-03-17 20:37:51

【问题描述】：

我正在尝试从 SwiftUI 结构（名字和姓氏）传递数据，但似乎无法使用 UIViewControllerRepresentable 中的数据更新 UIViewController 中的变量。

我已检查并确认我尝试从 SwiftUI 视图传入的数据是正确的。我需要做什么/更改以更新 UIViewController 中的 firstName 和 lastName 变量？

import UIKit
import PDFKit
import SwiftUI

class PDFPreviewViewController: UIViewController 
    public var documentData: Data?

    var firstName: String = "firstName did not load"
    var lastName: String = "lastName did not load"

    @IBOutlet weak var pdfView: PDFView!

    override func viewDidLoad() 
        super.viewDidLoad()

        let pdfCreator = PDFCreator(firstName: firstName, lastName: lastName, format: "test format")
        documentData = pdfCreator.createReleasePDF()
        if let data = documentData 
            pdfView.document = PDFDocument(data: data)
            pdfView.autoScales = true
        
    


struct PDFPreviewController: UIViewControllerRepresentable 
    var release: ModelRelease
    let vc = PDFPreviewViewController()

    func makeUIViewController(context: UIViewControllerRepresentableContext<PDFPreviewController>) -> UIViewController 

        let storyboard = UIStoryboard(name: "Preview", bundle: Bundle.main)
        let controller = storyboard.instantiateViewController(identifier: "Preview")

        vc.firstName = release.firstName
        vc.lastName = release.lastName

        return controller
    

    func updateUIViewController(_ uiViewController: UIViewController, context: UIViewControllerRepresentableContext<PDFPreviewController>) 
    


struct PDFPreviewControllerWrapper: View 
    @Environment(\.presentationMode) var presentationMode

    var release: ModelRelease

    var body: some View 
        NavigationView 
            PDFPreviewController(release: release)
            .navigationBarTitle(Text("Preview"))
            .navigationBarItems(trailing: Button(action: 
                self.presentationMode.wrappedValue.dismiss()
            ) 
                Text("Done")
                    .fontWeight(.bold)
                
            )
        
    

【参考方案1】：

创建可表示的视图控制器，您将参数设置到一个控制器但返回另一个控制器。可能您的意思是：

//let vc = PDFPreviewViewController() // don't think it is needed at all

func makeUIViewController(context: UIViewControllerRepresentableContext<PDFPreviewController>) -> UIViewController 

    let storyboard = UIStoryboard(name: "Preview", bundle: Bundle.main)
    let controller = storyboard.instantiateViewController(identifier: 
                         "Preview") as! PDFPreviewViewController

    controller.firstName = release.firstName // << here !
    controller.lastName = release.lastName   // << and here !

    return controller

【讨论】：

当我进行此更改时，我收到错误 Value of type 'UIViewController' has no member 'firstName' 和 lastName 的错误

@Dwillmore，已更新。实际上它是您的控制器，您现在应该是哪种类型。 =)