有没有办法在 SwiftUI 中复制手势或处理它们并将它们传递给子视图？

Posted 2023-02-24

【中文标题】有没有办法在 SwiftUI 中复制手势或处理它们并将它们传递给子视图？

【英文标题】：Are there any ways to copy gestures in SwiftUI or handle them and pass them down to child views?

【发布时间】：2020-10-06 22:03:30

【问题描述】：

我有两个相邻的TextEditor，我想同步它们的滚动状态，例如，如果我在左边滚动，右边应该显示相同。

//basic code
@State private var textLeft: String = "view left"
@State private var textRight: String = "view right"

var body: some View 
    HStack() 
        TextEditor(text: $textLeft)
        TextEditor(text: $textLeft)
        .gesture(DragGesture(coordinateSpace: .global)
             .updating($gestureState, body:  (value, state, transaction) in
                  print(value.translation)
             )
             .onChanged  value in
                  //this blocks the TextEditor to scroll
                  //or won't be called if the gesture is handled by the editor
                  //
                  //if I apply the offset to the other Editor 
                  //it results in weird looking behavior 
                  print(offset)
             
         )
    

我尝试了几件事，例如对其应用手势并捕捉运动并将其设置为另一个 .offset(value)，但 DragGesture 会阻止 TextEditor 或 TextEditor 会阻止拖动手势。

是否有任何方法，例如复制手势并将它们应用到另一个视图或通过 .gesture() 传递到视图本身？

感谢您的帮助！

【参考方案1】：

您可以尝试将 Gesture 提取到计算属性：

var dragGesture: some Gesture 
    DragGesture(coordinateSpace: .global)
        .updating($gestureState)  value, state, transaction in
            print(value.translation)
        
        .onChanged  value in
            // this blocks the TextEditor to scroll
            // or won't be called if the gesture is handled by the editor
            //
            // if I apply the offset to the other Editor
            // it results in weird looking behavior
            print(offset)
        

var body: some View 
    HStack 
        TextEditor(text: $textLeft)
            .gesture(dragGesture)
        TextEditor(text: $textLeft)
            .gesture(dragGesture)
    

【讨论】：

我试过了，但它并没有改变旧的行为:(

@DominikNöth 请同时显示onChanged中的代码。