Andrew_STOP_RU_WAR_IN_UA's questions

如何使某些点能够像视频中那样通过一组视图边缘进行拖动：

而不是自由拖拽：

我甚至不知道从哪里开始，因为没有 GeometryReader 我就无法测量视图的边界。

然而，GeometryReader 在这种情况下并不合适，因为这些是位于不同图层上的不同视图。

示例视图：

struct ContentView: View {
    @State var point: CGPoint = .zero
    
    var body: some View {
        ZStack {
            //foreach Nodes
            NodeView()
            
            NodeView()
                .offset(x:0, y:100)

            //foreach Points
            BezierPoint(p1: $point)
        }
    }
}

struct NodeView : View {
    // var nodeViewModel: NodeViewModel
    // with exact location in space

    var body: some View {
        Text("Business")
            .multilineTextAlignment(.center)
            .foregroundStyle(.red)
            .shadow(color: .black, radius: 2 )
            .frame(minHeight: 40)
            .padding( EdgeInsets(horizontal: 20, vertical: 14) )
            .background {
                // ANY Shape can be here
                RoundedRectangle(cornerRadius: 10)
            }
    }
}

struct BezierPoint: View {
    @Binding var p1: CGPoint
    
    let pointsSize: CGFloat = 15
    
    var body: some View {
        GeometryReader { reader in
            ControlPointHandle(size: pointsSize)
                .offset( CGSize(width: p1.x + reader.size.width/2, height: p1.y + reader.size.height/2) )
                .gesture(
                    DragGesture()
                        .onChanged { value in
                            self.p1 = value.location.relativeToCenter(of: reader.size, minus: true)
                        }
                )
        }
    }
}


private struct ControlPointHandle: View {
    let size: CGFloat
    
    var body: some View {
        Circle()
            .frame(width: size, height: size)
            .overlay(
                Circle()
                    .stroke(Color.blue, lineWidth: 2)
            )
            .offset(x: -size/2, y: -size/2)
    }
}


fileprivate extension CGPoint {
    func relativeToCenter(of size: CGSize, minus: Bool = false) -> CGPoint {
        let a: CGFloat = minus ? -1 : 1
        return CGPoint(x: x + a * size.width/2, y: y + a * size.height/2)
    }
}

我有以下代码：

public extension SymmetricKey {
    init?(base64Encoded base64EncodedKeyString: String) {
        guard let keyData = Data(base64Encoded: base64EncodedKeyString) else { return nil }
        self.init(data: keyData)
    }
    
    var base64: String {
        self.withUnsafeBytes { body in
            Data(body).base64EncodedString()
        }
    }
    
    init?(pass: String) {
        guard let passHash = passToHash(pass: pass) else { return nil }
        
        self.init(base64Encoded: passHash)
    }
}

fileprivate func passToHash(pass: String) -> String? {
    guard let passData = pass.data(using: .utf8) else { return nil }
    let hashed = SHA256.hash(data: passData)
    return hashed.compactMap { String(format: "%02x", $0) }.joined()
}

问题是如果我尝试使用，SymmetricKey我会看到错误：

操作无法完成。（CryptoKit.CryptoKitError 错误 1。）

此错误意味着密钥大小不正确。

如果我尝试比较SymmetricKey使用默认方式生成的 s 和从我的自定义初始化生成的 s ，我会看到差异：

5994471abb01112afcc18159f6cc74b4f511b99806da59b3caf5a9c173cacfc5 //from password
cfyk1v2dRIlVKHlpy8qBH71v4BXGSUHPUS3wLn1gzj0= //.bits256

我做错了什么？为什么哈希看起来不一样？