Question

我不明白为什么点击按钮没有出现额外的视图

struct ContentView: View {
@State private var isGlassesMenuShow = false
@State public var bgColor = Color.gray

var body: some View {
    HStack{
  
        VStack{
           
            SceneView(scene: getSirenHead(), options: [.autoenablesDefaultLighting,.allowsCameraControl]).frame(width:UIScreen.main.bounds.width - 50, height: UIScreen.main.bounds.height-100)
            GlassView(isOn: $isGlassesMenuShow)
        }
            Button("", action: {
               
                self.isGlassesMenuShow = true
                
            })}

这是视图类

struct GlassView: View {
@Binding var isOn: Bool

var body: some View {
if isOn{
    ScrollView(.horizontal) {
    HStack{
    ZStack{
    Button("", action: {
        
    }).frame(width: 100, height: 100).background(Color.white)
                Image("glass")
                    .resizable().frame(width: 100, height: 50)}
    ZStack{
    Button("", action: {
        
    }).frame(width: 100, height: 100).background(Color.white)
                Image("glass2")
                    .resizable().frame(width: 100, height: 50)}
    }}
}
else{
    EmptyView()
}

} }

当按下按钮时，所需的视图根本不会出现，但是当您在代码中手动设置为 true 时，它就会出现

Answer 1

它确实有效，当您按下“单击我”按钮时，会出现 GlassView。这是我的测试代码。

struct ContentView: View {
    @State private var isGlassesMenuShow = false
    @State public var bgColor = Color.gray
    
    var body: some View {
        HStack{
            VStack{
                Text("testing testing")
                GlassView(isOn: $isGlassesMenuShow)
            }
            Button("click me", action: { // <--- press this button and GlassView appears
                self.isGlassesMenuShow = true
            })}
    }
}

struct GlassView: View {
    @Binding var isOn: Bool
    
    var body: some View {
        if isOn{
            ScrollView(.horizontal) {
                HStack{
                    ZStack{
                        Button("button1", action: {
                            
                        }).frame(width: 100, height: 100).background(Color.white)
                        Image(systemName: "globe").resizable().frame(width: 100, height: 50)}
                    ZStack{
                        Button("button2", action: {
                            
                        }).frame(width: 100, height: 100).background(Color.white)
                        Image(systemName: "info").resizable().frame(width: 100, height: 50)}
                }}
        }
        else{
            EmptyView()
        }
    }
}

为什么 SwiftUI 中的 @state var 不会改变我的视图？

1 个答案: