如何在 SwiftUI 中创建多行 TextField？

Question

我一直在尝试在 SwiftUI 中创建一个多行 TextField，但我不知道该怎么做。

这是我目前拥有的代码：

struct EditorTextView : View {
    @Binding var text: String
    
    var body: some View {
        TextField($text)
            .lineLimit(4)
            .multilineTextAlignment(.leading)
            .frame(minWidth: 100, maxWidth: 200, minHeight: 100, maxHeight: .infinity, alignment: .topLeading)
    }
}

#if DEBUG
let sampleText = """
Very long line 1
Very long line 2
Very long line 3
Very long line 4
"""

struct EditorTextView_Previews : PreviewProvider {
    static var previews: some View {
        EditorTextView(text: .constant(sampleText))
            .previewLayout(.fixed(width: 200, height: 200))
    }
}
#endif

但这是输出：

Answer 1

使用 Text()，您可以使用 .lineLimit(nil) 实现此目的，并且文档建议此应该也适用于 TextField()。但是，我可以确认这目前没有按预期工作。

我怀疑有错误 - 建议使用反馈助手提交报告。我已经这样做了，ID是FB6124711。

编辑：iOS 14 的更新：改用新的 TextEditor。

Answer 2

更新：虽然 Xcode11 beta 4 现在支持 TextView，但我发现包装 UITextView 仍然是让可编辑的多行文本发挥作用的最佳方式。例如，TextView 存在显示故障，文本在视图中显示不正确。

原始（测试版 1）答案：

现在，您可以包装一个 UITextView 来创建一个可组合的 View:

import SwiftUI
import Combine

final class UserData: BindableObject  {
    let didChange = PassthroughSubject<UserData, Never>()

    var text = "" {
        didSet {
            didChange.send(self)
        }
    }

    init(text: String) {
        self.text = text
    }
}

struct MultilineTextView: UIViewRepresentable {
    @Binding var text: String

    func makeUIView(context: Context) -> UITextView {
        let view = UITextView()
        view.isScrollEnabled = true
        view.isEditable = true
        view.isUserInteractionEnabled = true
        return view
    }

    func updateUIView(_ uiView: UITextView, context: Context) {
        uiView.text = text
    }
}

struct ContentView : View {
    @State private var selection = 0
    @EnvironmentObject var userData: UserData

    var body: some View {
        TabbedView(selection: $selection){
            MultilineTextView(text: $userData.text)
                .tabItemLabel(Image("first"))
                .tag(0)
            Text("Second View")
                .font(.title)
                .tabItemLabel(Image("second"))
                .tag(1)
        }
    }
}

#if DEBUG
struct ContentView_Previews : PreviewProvider {
    static var previews: some View {
        ContentView()
            .environmentObject(UserData(
                text: """
                        Some longer text here
                        that spans a few lines
                        and runs on.
                        """
            ))

    }
}
#endif

Answer 3

这在 Xcode 版本 11.0 beta 6 中包装了 UITextView（仍在 Xcode 11 GM seed 2 中工作）：

import SwiftUI

struct ContentView: View {
     @State var text = ""

       var body: some View {
        VStack {
            Text("text is: \(text)")
            TextView(
                text: $text
            )
                .frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: .infinity)
        }

       }
}

struct TextView: UIViewRepresentable {
    @Binding var text: String

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

    func makeUIView(context: Context) -> UITextView {

        let myTextView = UITextView()
        myTextView.delegate = context.coordinator

        myTextView.font = UIFont(name: "HelveticaNeue", size: 15)
        myTextView.isScrollEnabled = true
        myTextView.isEditable = true
        myTextView.isUserInteractionEnabled = true
        myTextView.backgroundColor = UIColor(white: 0.0, alpha: 0.05)

        return myTextView
    }

    func updateUIView(_ uiView: UITextView, context: Context) {
        uiView.text = text
    }

    class Coordinator : NSObject, UITextViewDelegate {

        var parent: TextView

        init(_ uiTextView: TextView) {
            self.parent = uiTextView
        }

        func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
            return true
        }

        func textViewDidChange(_ textView: UITextView) {
            print("text now: \(String(describing: textView.text!))")
            self.parent.text = textView.text
        }
    }
}

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

Answer 4

好的，我开始使用@sas 方法，但它真的需要它看起来像内容适合的多行文本字段等。这就是我所拥有的。希望它会对其他人有所帮助...使用 Xcode 11.1.

假设自定义 MultilineTextField 具有：
1。内容契合
2。自动对焦
3。占位符
4。提交时

import SwiftUI
import UIKit

fileprivate struct UITextViewWrapper: UIViewRepresentable {
    typealias UIViewType = UITextView

    @Binding var text: String
    @Binding var calculatedHeight: CGFloat
    var onDone: (() -> Void)?

    func makeUIView(context: UIViewRepresentableContext<UITextViewWrapper>) -> UITextView {
        let textField = UITextView()
        textField.delegate = context.coordinator

        textField.isEditable = true
        textField.font = UIFont.preferredFont(forTextStyle: .body)
        textField.isSelectable = true
        textField.isUserInteractionEnabled = true
        textField.isScrollEnabled = false
        textField.backgroundColor = UIColor.clear
        if nil != onDone {
            textField.returnKeyType = .done
        }

        textField.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
        return textField
    }

    func updateUIView(_ uiView: UITextView, context: UIViewRepresentableContext<UITextViewWrapper>) {
        if uiView.text != self.text {
            uiView.text = self.text
        }
        if uiView.window != nil, !uiView.isFirstResponder {
            uiView.becomeFirstResponder()
        }
        UITextViewWrapper.recalculateHeight(view: uiView, result: $calculatedHeight)
    }

    fileprivate static func recalculateHeight(view: UIView, result: Binding<CGFloat>) {
        let newSize = view.sizeThatFits(CGSize(width: view.frame.size.width, height: CGFloat.greatestFiniteMagnitude))
        if result.wrappedValue != newSize.height {
            DispatchQueue.main.async {
                result.wrappedValue = newSize.height // !! must be called asynchronously
            }
        }
    }

    func makeCoordinator() -> Coordinator {
        return Coordinator(text: $text, height: $calculatedHeight, onDone: onDone)
    }

    final class Coordinator: NSObject, UITextViewDelegate {
        var text: Binding<String>
        var calculatedHeight: Binding<CGFloat>
        var onDone: (() -> Void)?

        init(text: Binding<String>, height: Binding<CGFloat>, onDone: (() -> Void)? = nil) {
            self.text = text
            self.calculatedHeight = height
            self.onDone = onDone
        }

        func textViewDidChange(_ uiView: UITextView) {
            text.wrappedValue = uiView.text
            UITextViewWrapper.recalculateHeight(view: uiView, result: calculatedHeight)
        }

        func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
            if let onDone = self.onDone, text == "\n" {
                textView.resignFirstResponder()
                onDone()
                return false
            }
            return true
        }
    }

}

struct MultilineTextField: View {

    private var placeholder: String
    private var onCommit: (() -> Void)?

    @Binding private var text: String
    private var internalText: Binding<String> {
        Binding<String>(get: { self.text } ) {
            self.text = [=10=]
            self.showingPlaceholder = [=10=].isEmpty
        }
    }

    @State private var dynamicHeight: CGFloat = 100
    @State private var showingPlaceholder = false

    init (_ placeholder: String = "", text: Binding<String>, onCommit: (() -> Void)? = nil) {
        self.placeholder = placeholder
        self.onCommit = onCommit
        self._text = text
        self._showingPlaceholder = State<Bool>(initialValue: self.text.isEmpty)
    }

    var body: some View {
        UITextViewWrapper(text: self.internalText, calculatedHeight: $dynamicHeight, onDone: onCommit)
            .frame(minHeight: dynamicHeight, maxHeight: dynamicHeight)
            .background(placeholderView, alignment: .topLeading)
    }

    var placeholderView: some View {
        Group {
            if showingPlaceholder {
                Text(placeholder).foregroundColor(.gray)
                    .padding(.leading, 4)
                    .padding(.top, 8)
            }
        }
    }
}

#if DEBUG
struct MultilineTextField_Previews: PreviewProvider {
    static var test:String = ""//some very very very long description string to be initially wider than screen"
    static var testBinding = Binding<String>(get: { test }, set: {
//        print("New value: \([=10=])")
        test = [=10=] } )

    static var previews: some View {
        VStack(alignment: .leading) {
            Text("Description:")
            MultilineTextField("Enter some text here", text: testBinding, onCommit: {
                print("Final text: \(test)")
            })
                .overlay(RoundedRectangle(cornerRadius: 4).stroke(Color.black))
            Text("Something static here...")
            Spacer()
        }
        .padding()
    }
}
#endif

backup

Answer 5

目前，最好的解决方案是使用我创建的名为 TextView 的包。

您可以使用 Swift 包管理器安装它（在 README 中有解释）。它允许可切换的编辑状态和大量自定义（在 README 中也有详细说明）。

这是一个例子：

import SwiftUI
import TextView

struct ContentView: View {
    @State var input = ""
    @State var isEditing = false

    var body: some View {
        VStack {
            Button(action: {
                self.isEditing.toggle()
            }) {
                Text("\(isEditing ? "Stop" : "Start") editing")
            }
            TextView(text: $input, isEditing: $isEditing)
        }
    }
}

在该示例中，您首先定义了两个 @State 变量。一个用于文本，每当输入文本时 TextView 都会写入文本，另一个用于 TextView 的 isEditing 状态。

TextView 在 selected 时切换 isEditing 状态。当您单击该按钮时，也会切换 isEditing 状态，当 true 时将显示键盘和 select TextView，而 [=16= 时将显示 select TextView ].

Answer 6

iOS 14 - 原生 SwiftUI

叫做TextEditor

struct ContentView: View {
    @State var text: String = "Multiline \ntext \nis called \nTextEditor"

    var body: some View {
        TextEditor(text: $text)
    }
}

动态生长高度：

如果您希望它随着您的输入而增长，请将其嵌入到带有 Text 的 ZStack 中，如下所示：

iOS 13 - 使用 UITextView

您可以通过此结构在 SwiftUI 代码中使用本机 UITextView：

struct TextView: UIViewRepresentable {
    
    typealias UIViewType = UITextView
    var configuration = { (view: UIViewType) in }
    
    func makeUIView(context: UIViewRepresentableContext<Self>) -> UIViewType {
        UIViewType()
    }
    
    func updateUIView(_ uiView: UIViewType, context: UIViewRepresentableContext<Self>) {
        configuration(uiView)
    }
}

用法

struct ContentView: View {
    var body: some View {
        TextView() {
            [=12=].textColor = .red
            // Any other setup you like
        }
    }
}

优点：

支持 iOS 13
与遗留代码共享
在 UIKit
完全可定制
原始 UITextView

Answer 7

@Meo Flute 的回答很棒！但它不适用于多级文本输入。结合@Asperi 的回答，这里是固定的，我还添加了对占位符的支持只是为了好玩！

struct TextView: UIViewRepresentable {
    var placeholder: String
    @Binding var text: String

    var minHeight: CGFloat
    @Binding var calculatedHeight: CGFloat

    init(placeholder: String, text: Binding<String>, minHeight: CGFloat, calculatedHeight: Binding<CGFloat>) {
        self.placeholder = placeholder
        self._text = text
        self.minHeight = minHeight
        self._calculatedHeight = calculatedHeight
    }

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

    func makeUIView(context: Context) -> UITextView {
        let textView = UITextView()
        textView.delegate = context.coordinator

        // Decrease priority of content resistance, so content would not push external layout set in SwiftUI
        textView.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)

        textView.isScrollEnabled = false
        textView.isEditable = true
        textView.isUserInteractionEnabled = true
        textView.backgroundColor = UIColor(white: 0.0, alpha: 0.05)

        // Set the placeholder
        textView.text = placeholder
        textView.textColor = UIColor.lightGray

        return textView
    }

    func updateUIView(_ textView: UITextView, context: Context) {
        textView.text = self.text

        recalculateHeight(view: textView)
    }

    func recalculateHeight(view: UIView) {
        let newSize = view.sizeThatFits(CGSize(width: view.frame.size.width, height: CGFloat.greatestFiniteMagnitude))
        if minHeight < newSize.height && $calculatedHeight.wrappedValue != newSize.height {
            DispatchQueue.main.async {
                self.$calculatedHeight.wrappedValue = newSize.height // !! must be called asynchronously
            }
        } else if minHeight >= newSize.height && $calculatedHeight.wrappedValue != minHeight {
            DispatchQueue.main.async {
                self.$calculatedHeight.wrappedValue = self.minHeight // !! must be called asynchronously
            }
        }
    }

    class Coordinator : NSObject, UITextViewDelegate {

        var parent: TextView

        init(_ uiTextView: TextView) {
            self.parent = uiTextView
        }

        func textViewDidChange(_ textView: UITextView) {
            // This is needed for multistage text input (eg. Chinese, Japanese)
            if textView.markedTextRange == nil {
                parent.text = textView.text ?? String()
                parent.recalculateHeight(view: textView)
            }
        }

        func textViewDidBeginEditing(_ textView: UITextView) {
            if textView.textColor == UIColor.lightGray {
                textView.text = nil
                textView.textColor = UIColor.black
            }
        }

        func textViewDidEndEditing(_ textView: UITextView) {
            if textView.text.isEmpty {
                textView.text = parent.placeholder
                textView.textColor = UIColor.lightGray
            }
        }
    }
}

这样使用：

struct ContentView: View {
    @State var text: String = ""
    @State var textHeight: CGFloat = 150

    var body: some View {
        ScrollView {
            TextView(placeholder: "", text: self.$text, minHeight: self.textHeight, calculatedHeight: self.$textHeight)
            .frame(minHeight: self.textHeight, maxHeight: self.textHeight)
        }
    }
}

Answer 8

适用于Xcode12和iOS14，真的很简单。

import SwiftUI

struct ContentView: View {
    
    @State private var text = "Hello world"
    
    var body: some View {
        TextEditor(text: $text)
    }
}

Answer 9

SwiftUI TextView(UIViewRepresentable) 具有以下可用参数： fontStyle、isEditable、backgroundColor、borderColor 和边框宽度

TextView(text: self.$viewModel.text, fontStyle: .body, isEditable: true, backgroundColor: UIColor.white, borderColor: UIColor.lightGray, borderWidth: 1.0) .padding()

文本视图（UIViewRepresentable）

struct TextView: UIViewRepresentable {

@Binding var text: String
var fontStyle: UIFont.TextStyle
var isEditable: Bool
var backgroundColor: UIColor
var borderColor: UIColor
var borderWidth: CGFloat

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

func makeUIView(context: Context) -> UITextView {

    let myTextView = UITextView()
    myTextView.delegate = context.coordinator

    myTextView.font = UIFont.preferredFont(forTextStyle: fontStyle)
    myTextView.isScrollEnabled = true
    myTextView.isEditable = isEditable
    myTextView.isUserInteractionEnabled = true
    myTextView.backgroundColor = backgroundColor
    myTextView.layer.borderColor = borderColor.cgColor
    myTextView.layer.borderWidth = borderWidth
    myTextView.layer.cornerRadius = 8
    return myTextView
}

func updateUIView(_ uiView: UITextView, context: Context) {
    uiView.text = text
}

class Coordinator : NSObject, UITextViewDelegate {

    var parent: TextView

    init(_ uiTextView: TextView) {
        self.parent = uiTextView
    }

    func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
        return true
    }

    func textViewDidChange(_ textView: UITextView) {
        self.parent.text = textView.text
    }
}

}

Answer 10

MacOS 实现

struct MultilineTextField: NSViewRepresentable {
    
    typealias NSViewType = NSTextView
    private let textView = NSTextView()
    @Binding var text: String
    
    func makeNSView(context: Context) -> NSTextView {
        textView.delegate = context.coordinator
        return textView
    }
    func updateNSView(_ nsView: NSTextView, context: Context) {
        nsView.string = text
    }
    func makeCoordinator() -> Coordinator {
        return Coordinator(self)
    }
    class Coordinator: NSObject, NSTextViewDelegate {
        let parent: MultilineTextField
        init(_ textView: MultilineTextField) {
            parent = textView
        }
        func textDidChange(_ notification: Notification) {
            guard let textView = notification.object as? NSTextView else { return }
            self.parent.text = textView.string
        }
    }
}

以及如何使用

struct ContentView: View {

    @State var someString = ""

    var body: some View {
         MultilineTextField(text: $someString)
    }
}

Answer 11

您可以只使用 TextEditor(text: $text) 然后添加任何修饰符，例如高度。

Answer 12

SwiftUI 具有 TextEditor，它类似于 TextField，但提供了包含多行的长格式文本输入：

var body: some View {
    NavigationView{
        Form{
            Section{
                List{
                    Text(question6)
                    TextEditor(text: $responseQuestion6).lineLimit(4)
                    Text(question7)
                    TextEditor(text:  $responseQuestion7).lineLimit(4)
                }
            }
        }
    }
}

Answer 13

这是我根据 Asperi 的回答得出的结论。此解决方案 不需要计算和传播大小 。它在 TextView 本身内部使用 contentSize 和 intrinsicContentSize：

struct TextView: UIViewRepresentable {
    @Binding var text: String
    
    func makeUIView(context: UIViewRepresentableContext<TextView>) -> UITextView {
        let textView = UIKitTextView()
        
        textView.delegate = context.coordinator
        
        return textView
    }
    
    func updateUIView(_ textView: UITextView, context: UIViewRepresentableContext<TextView>) {
        if textView.text != self.text {
            textView.text = self.text
        }
    }
    
    func makeCoordinator() -> Coordinator {
        return Coordinator(text: $text)
    }
    
    final private class UIKitTextView: UITextView {
        override var contentSize: CGSize {
            didSet {
                invalidateIntrinsicContentSize()
            }
        }
        
        override var intrinsicContentSize: CGSize {
            // Or use e.g. `min(contentSize.height, 150)` if you want to restrict max height
            CGSize(width: UIView.noIntrinsicMetric, height: contentSize.height)
        }
    }
    
    final class Coordinator: NSObject, UITextViewDelegate {
        var text: Binding<String>
        
        init(text: Binding<String>) {
            self.text = text
        }
        
        func textViewDidChange(_ textView: UITextView) {
            text.wrappedValue = textView.text
        }
    }
}

Answer 14

// You can use the .multiLineTextAlignment modifier

TextField("Random text", text: $text)
    .multiLineTextAlignment(.leading)

// This aligns the text to the left
// There are more properties beside '.leading', more can be found at the source

Answer 15

只想分享我的 UITextView 解决方案减去协调器。我注意到 SwiftUI 调用 UITextView.intrinsicContentSize 时没有告诉它它应该适合的宽度。默认情况下 UITextView 假定它具有无限宽度来布置内容，因此如果它只有一行文本，它将 return 适合那一行所需的大小。

为了解决这个问题，我们可以子类化 UITextView 并在视图的宽度发生变化时使固有尺寸无效，并在计算固有尺寸时考虑宽度。

struct TextView: UIViewRepresentable {

  var text: String

  public init(_ text: String) {
    self.text = text
  }

  public func makeUIView(context: Context) -> UITextView {
    let textView = WrappedTextView()
    textView.backgroundColor = .clear
    textView.isScrollEnabled = false
    textView.textContainerInset = .zero
    textView.textContainer.lineFragmentPadding = 0
    textView.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
    textView.setContentHuggingPriority(.defaultHigh, for: .vertical)
    return textView
  }

  public func updateUIView(_ uiView: UITextView, context: Context) {
    uiView.text = text
  }
}

class WrappedTextView: UITextView {

  private var lastWidth: CGFloat = 0

  override func layoutSubviews() {
    super.layoutSubviews()
    if bounds.width != lastWidth {
      lastWidth = bounds.width
      invalidateIntrinsicContentSize()
    }
  }

  override var intrinsicContentSize: CGSize {
    let size = sizeThatFits(
      CGSize(width: lastWidth, height: UIView.layoutFittingExpandedSize.height))
    return CGSize(width: size.width.rounded(.up), height: size.height.rounded(.up))
  }
}

如何在 SwiftUI 中创建多行 TextField？

How do I create a multiline TextField in SwiftUI?

textfield

textview

ios

swiftui

iOS 14 - 原生 SwiftUI

动态生长高度：

iOS 13 - 使用 UITextView

用法

优点：