Question

当这些数据是新的“真理之源”时，如何用新数据重绘Shape？下图显示，只有“ Text（” ...“）视图使用ObservedObject更新，Shape仅绘制一次。

import SwiftUI

struct ContentView: View {
    @ObservedObject var cntrl:Controller=Controller()
    var body: some View {
        VStack {
            subviewone(cntrl: cntrl)
            graph(cntrl: cntrl)
                .stroke()
                .fill(Color.red)
            subviewone(cntrl: cntrl)
        }.padding(.all)
    }
}

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

struct graph: Shape {
    @ObservedObject var cntrl:Controller
    func path(in rect: CGRect) -> Path {
        print("function beeing called")
        return Path { path in
            path.addArc(center: CGPoint(x: rect.midX, y: rect.midY), radius: CGFloat(100-cntrl.test), startAngle: Angle.init(degrees: 0), endAngle: Angle.init(degrees: 360), clockwise: true)
        }
    }


}

struct subviewone: View {
    @ObservedObject var cntrl:Controller
    var body: some View {
        VStack {
            Text("******")
            Text("\(cntrl.test)")
            Text("******")

        }

    }
}

class Controller:ObservableObject {

    @Published var test=0

    init() {
        _ = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) {_ in
            self.test+=1
        }
    }

}

如果我省略.stroke（）和.fill（Color.red），则该代码有效


struct ContentView: View {
    @ObservedObject var cntrl:Controller=Controller()
    var body: some View {
        VStack {
            subviewone(cntrl: cntrl)
            graph(cntrl: cntrl)
            subviewone(cntrl: cntrl)
        }.padding(.all)
    }
}

谢谢您的任何建议。 Libor

Answer 1

尝试一下-已通过13.4测试

struct ContentView: View {

    @EnvironmentObject var controller : Controller

    var body: some View {
        VStack {
            subviewone()
                .environmentObject(controller)
            graph(radius: controller.test)
                .stroke()
                .fill(Color.red)
            subviewone()
            .environmentObject(controller)
        }.padding(.all)
    }
}

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

struct graph: Shape {

    @State var radius : CGFloat

    func path(in rect: CGRect) -> Path {
        print("function beeing called")
        return Path { path in
            path.addArc(center: CGPoint(x: rect.midX, y: rect.midY), radius: CGFloat(100-radius), startAngle: Angle.init(degrees: 0), endAngle: Angle.init(degrees: 360), clockwise: true)
        }
    }


}

struct subviewone: View {
    @EnvironmentObject var controller : Controller
    var body: some View {
        VStack {
            Text("******")
            Text("\(controller.test)")
            Text("******")

        }

    }
}

class Controller:ObservableObject {

    @Published var test : CGFloat = 0

    init() {
        _ = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) {_ in
            self.test+=1
        }
    }

}

Answer 2

在 Shape 上，您永远不能一次调用 [ERROR] Failed to execute goal on project dss-asic-xades: Could not resolve dependencies for project eu.europa.ec.joinup.sd-dss:dss-asic-xades:jar:5.8.RC1: Failure to find eu.europa.ec.joinup.sd-dss:dss-asic-common:jar:tests:5.8.RC1 in https://repo.maven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced -> [Help 1] 和 stroke，因为第一次调用 fill 或 stroke 返回的是视图，不再是 Shape。< /p>

形状不会重绘

2 个答案: