ios - SwiftUI HStack 元素等高

Question

我希望两个按钮的高度相同，类似于Equal HeightUIKit 中的约束。

• 不想指定框架，让 SwiftUI 处理它，但 HStack 中的元素应该是相同的高度。
• 按钮应具有相同的宽度和高度，并适应较长的文本并增加其框架大小
• 两个按钮都应该显示它们的完整文本（不应该使用缩放/适合的字体）

示例代码

struct SampleView: View {
    var body: some View {
        
        GeometryReader { gr in
            VStack {
                ScrollView {
                    VStack {
                        // Fills whatever space is left
                        Rectangle()
                            .foregroundColor(.clear)

                        Image(systemName: "applelogo")
                            .resizable()
                            .frame(width: gr.size.width * 0.5, height: gr.size.height * 0.3, alignment: .center)
                            //.border(Color.blue)
                            .padding(.bottom, gr.size.height * 0.06)


                        Text("SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME")
                            .fontWeight(.regular)
                            .foregroundColor(.green)
                            .multilineTextAlignment(.center)
                            .padding(.horizontal, 40)
                            .layoutPriority(1)


                        // Fills 15 %
                        Rectangle()
                            .frame(height: gr.size.height * 0.12)
                            .foregroundColor(.clear)

                    DynamicallyScalingView()
                        .padding(.horizontal, 20)
                        .padding(.bottom, 20)

                    }

                    // Makes the content stretch to fill the whole scroll view, but won't be limited (it can grow beyond if needed)
                    .frame(minHeight: gr.size.height)
                }
            }
        }
    }
}

struct DynamicallyScalingView: View {
    @State private var labelHeight = CGFloat.zero     // << here !!

    var body: some View {
        HStack {
            Button(action: {
            }, label: {
                Text("Button 1")
            })
            .foregroundColor(Color.white)
            .padding(.vertical)
            .frame(minWidth: 0, maxWidth: .infinity)
            .frame(minHeight: labelHeight)
            .background(Color.blue)
            .cornerRadius(8)

            Button(action: {
            }, label: {
                Text("Larger Button 2 Text Text2")
            })
            .foregroundColor(Color.white)
            .padding(.vertical)
            .frame(minWidth: 0, maxWidth: .infinity)
            .background(Color.blue)
            .cornerRadius(8)
            .background(GeometryReader {      // << set right side height
                Color.clear.preference(key: ViewHeightKey.self,
                                       value: $0.frame(in: .local).size.height)
            })
        }
        .onPreferenceChange(ViewHeightKey.self) { // << read right side height
            self.labelHeight = $0        // << here !!
        }
        .padding(.horizontal)
    }
}

struct ViewHeightKey: PreferenceKey {
    static var defaultValue: CGFloat { 0 }
    static func reduce(value: inout Value, nextValue: () -> Value) {
        value = value + nextValue()
    }
}

struct SampleView_Previews: PreviewProvider {
    static var previews: some View {
        SampleView().previewDevice("iPhone SE (2nd generation)")
    }
}

标签： iosswiftswiftuiscrollviewgeometryreader

Answer 1

ViewHeightKey您可以在首选项键中设置最大值：

struct ViewHeightKey: PreferenceKey {
    static var defaultValue: CGFloat { 0 }
    static func reduce(value: inout Value, nextValue: () -> Value) {
        value = max(value, nextValue()) // set the `max` value (from both buttons)
    }
}

然后从两个按钮读取视图高度并强制垂直fixedSize：

struct DynamicallyScalingView: View {
    @State private var labelHeight = CGFloat.zero

    var body: some View {
        HStack {
            Button(action: {}, label: {
                Text("SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME")
            })
                .foregroundColor(Color.white)
                .padding(.vertical)
                .frame(minWidth: 0, maxWidth: .infinity)
                .frame(minHeight: labelHeight) // min height for both buttons
                .background(Color.blue)
                .cornerRadius(8)
                .fixedSize(horizontal: false, vertical: true) // expand vertically
                .background(GeometryReader { // apply to both buttons
                    Color.clear
                        .preference(
                            key: ViewHeightKey.self,
                            value: $0.frame(in: .local).size.height
                        )
                })

            Button(action: {}, label: {
                Text("jahlsd")
            })
                .foregroundColor(Color.white)
                .padding(.vertical)
                .frame(minWidth: 0, maxWidth: .infinity)
                .frame(minHeight: labelHeight)
                .background(Color.blue)
                .cornerRadius(8)
                .fixedSize(horizontal: false, vertical: true)
                .background(GeometryReader {
                    Color.clear
                        .preference(
                            key: ViewHeightKey.self,
                            value: $0.frame(in: .local).size.height
                        )
                })
        }
        .onPreferenceChange(ViewHeightKey.self) {
            self.labelHeight = $0
        }
        .padding(.horizontal)
    }
}

注意：由于按钮现在相似，下一步是将它们提取为另一个组件以避免重复。