Question

我尝试在SwiftUI中构建相当复杂的View。结构是这样的：

struct ContentView<V: SpaceVertexProtocol>: View  where V.Coord.Axis : StyledAxisProtocol{
    
    @EnvironmentObject var environment: ViewsEnvironments<V>
    @ObservedObject var global: GlobalEnvironment<V>
    
    var body: some View {
        // It will be HStack, for a while just one view
        SpaceVerticesView(coordinates: $global.coordinates, vertices: $global.vertices)    
                .padding(EdgeInsets(top: 5, leading: 5, bottom: 5, trailing: 5))
                .environmentObject(environment.spaceVerticesView)
    }
}

public struct SpaceVerticesView<V:SpaceVertexProtocol> : View {
    ...
    @Binding var coordinates : [V.Coord]
    ...
    func updateCoordnates { 
       coordinates = ... // yes, this updates view, they're changed by `coordinates[index].at = something`
    }
    public var body: some View {
        ...
        SpotsView(coordinates: $coordinates,....)
        ...
    }

struct SpotsView<V:SpaceVertexProtocol> : View {
    ...
    @Binding var coordinates: [V.Coord]
    var spots: [SpotView<V>] {
         var result: [SpotView<V>] = []
         ...
         //counts and adds views initiated as:
            result.append(SpotView(coordinates: $coordinates,...)
         ... 
        return result
    }

    var body: some View {
        return ZStack {
            // makes some SpotView on top
            ForEach(0..<spots.count, id: \.self) { index in
                return self.spots[index]
            }
        }
    }

和另外两个级别（总是coordinates作为$coordinates传递给@Binding变量。在最深的视图中，var body返回Shape

    var body {
       ...
       return spotShape
        .contentShape(spotShape.clickArea).offset(x: 0, y: shift)
        .onTapGesture {
            print ("Tap gesture:",self)
            print (self.coordinates, targetCoordinates)
            self.coordinates = targetCoordinates

我可以看到coordinates已更新，但视图未重绘。如果单击clickArea之外的位置，则会触发SpaceVerticesView.updateCoordinates(...)，coordinates会更改，并且视图会重绘。 Shape @Binding无效吗？为什么没有反应？

当coordinates是@EnvironmentObject的一部分时，就可以了。

ObservedObject的更改不会重绘SwiftUI视图

0 个答案: