3

我正在尝试使用 SwiftUI 制作一个可移动的按钮。从它看起来这应该可以工作。我曾尝试将带有文本的按钮放在另一个 ZStack 中，并且有一秒钟它正在工作，但是一旦我释放按钮，拖动就停止了，我不能再拖动了。我注意到尽管按钮已移动，但水龙头仍留在中心。拖动看起来也有问题。

 struct CircleButton: View {
@State private var dragAmount = CGSize.zero
var body: some View {
    ZStack {
        Button(action: performAction){
            ZStack {
                Circle()
                    .foregroundColor(.blue)
                    .frame(width: 100, height: 100)
                Text("Move me")
                    .foregroundColor(.white)
                    .font(.system(.caption, design: .serif))
            }
        }
        .animation(.default)
        .offset(self.dragAmount)
    }
    .gesture(
        DragGesture()
            .onChanged { self.dragAmount = $0.translation})
}

func performAction(){
    print("button pressed")
 }
}

我试过这个：

struct CircleButton: View {
@State private var dragAmount = CGSize.zero
var body: some View {
    ZStack {
        ZStack {
            Button(action: performAction){
                Circle()
                    .foregroundColor(.blue)
                    .frame(width: 100, height: 100)
            }
            Text("Tap me")
        }
        .offset(self.dragAmount)
        .animation(.default)
    }
    .gesture(
        DragGesture()
            .onChanged{ self.dragAmount = $0.translation})
}

func performAction(){
    print("button pressed")
 }
}
4

3 回答 3

6

这是一个可能的方法的演示。经测试并适用于 Xcode 11.4 / iOS 13.4

演示

另请参阅内联注释。

struct CircleButton: View {
    @State private var dragAmount: CGPoint?
    var body: some View {
        GeometryReader { gp in // just to center initial position
            ZStack {
                Button(action: self.performAction) {
                    ZStack {
                        Circle()
                            .foregroundColor(.blue)
                            .frame(width: 100, height: 100)
                        Text("Move me")
                            .foregroundColor(.white)
                            .font(.system(.caption, design: .serif))
                    }
                }
                .animation(.default)
                .position(self.dragAmount ?? CGPoint(x: gp.size.width / 2, y: gp.size.height / 2))
                .highPriorityGesture(  // << to do no action on drag !!
                    DragGesture()
                        .onChanged { self.dragAmount = $0.location})
            }
            .frame(maxWidth: .infinity, maxHeight: .infinity) // full space
        }
    }

    func performAction() {
        print("button pressed")
    }
}
于 2020-04-17T05:42:13.830 回答
3

我在这里找到了ohayon的简单解决方案 。只是一个 ViewModifier 和一个扩展：

struct DraggablePita: View {
  var body: some View {
    Image(uiImage: UIImage(named: "pita.png")!)
      .draggable() // Add the new, custom modifier to make this draggable
  }
}

// Handle dragging
struct DraggableView: ViewModifier {
  @State var offset = CGPoint(x: 0, y: 0)

  func body(content: Content) -> some View {
    content
      .gesture(DragGesture(minimumDistance: 0)
        .onChanged { value in
          self.offset.x += value.location.x - value.startLocation.x
          self.offset.y += value.location.y - value.startLocation.y
      })
      .offset(x: offset.x, y: offset.y)
  }
}

// Wrap `draggable()` in a View extension to have a clean call site
extension View {
  func draggable() -> some View {
    return modifier(DraggableView())
  }
}
于 2020-10-16T02:35:18.710 回答
1

不同而简洁的东西怎么样：

import SwiftUI

struct ContentView: View {
var body: some View {
    CircleButton()
}
}

struct CircleButton: View {

@State private var pos = CGPoint(x:222,y:222) // just for testing

var body: some View {
    theButton.position(self.pos).highPriorityGesture(self.drag)
}

var theButton: some View {
    ZStack {
        Circle()
            .foregroundColor(.blue)
            .frame(width: 100, height: 100)
            .onTapGesture { self.performAction() }
        Text("Tap me")
            .foregroundColor(.white)
            .font(.system(.caption, design: .serif))
    }
}

func performAction(){
    print("button pressed")
}

var drag: some Gesture {
    DragGesture().onChanged { value in self.pos = CGPoint(x: value.location.x, y: value.location.y)}
}
}
于 2020-04-17T07:00:15.777 回答