Ios SwiftUI：.toolbar 不适用于 UITextView

SwiftUItoolbar不知道UIKit视图，所以它不会在UITextView中添加工具栏.

您仍然可以使用UIKit API添加工具栏:

let toolbar = UIToolbar()
toolbar.items = [...]
editor.inputAccessoryView = toolbar
toolbar.translatesAutoresizingMaskIntoConstraints = false

如果你想使用SwiftUI来编写工具栏的内容，你必须在协调器中添加一个UIHostingController.

出于某种原因，添加单个UIBarButtonItem(customView: hostingController.view)会使用户无法按下SwiftUIButton.你have要把整个inputAccessoryView变成一个SwiftUI.

示例:

// UIViewRepresentable and Coordinator design inspired by https://stackoverflow.com/a/74788978/5133585
struct MyUITextView<Toolbar: View>: UIViewRepresentable {
    init(text: Binding<String>, @ViewBuilder toolbar: @escaping () -> Toolbar) {
        self._text = text
        self.toolbar = toolbar
    }
    
    @Binding var text: String
    let toolbar: () -> Toolbar
    
    func makeCoordinator() -> Coordinator {
        Coordinator(hostingVC: UIHostingController(rootView: toolbar()))
    }
    
    func makeUIView(context: Context) -> UITextView {
        context.coordinator.editor
    }
    
    func updateUIView(_ uiView: UITextView, context: Context) {
        uiView.text = text
         context.coordinator.stringDidChange = { string in
            text = string
        }
    }
    
    class Coordinator: NSObject, UITextViewDelegate {
        
        let hostingVC: UIHostingController<Toolbar>
        
        init(hostingVC: UIHostingController<Toolbar>) {
            self.hostingVC = hostingVC
            hostingVC.sizingOptions = [.intrinsicContentSize]
        }
        
        lazy var editor: UITextView = {
            let editor = UITextView()
            editor.delegate = self
            editor.inputAccessoryView = hostingVC.view
            editor.inputAccessoryView?.translatesAutoresizingMaskIntoConstraints = false
            return editor
        }()
        
        var stringDidChange: ((String) -> ())?
        
        func textViewDidChange(_ textView: UITextView) {
            stringDidChange?(textView.text)
        }
    }
}

MyUITextView(text: $uitextView) {
    // this HStack is for imitating the UIToolbar
    HStack {
        Button("Click") { print("Foo") }
            .padding()
        Spacer()
    }
    .background(.bar.shadow(.drop(radius: 1)))
}
.border(.black, width: 1)
.frame(maxHeight: 40)