在macOS上的SwiftUI中将颜色从源拖放到目标

import SwiftUI

struct ContentView: View {
    @State private var sourceColor: Color = .red
    @State private var targetColor: Color = .gray
    
    var body: some View {
        VStack {
            // 源视图
            Circle()
                .fill(sourceColor)
                .frame(width: 100, height: 100)
                .gesture(
                    DragGesture()
                        .onChanged { _ in
                            // 当拖动手势开始时，更新源颜色为随机颜色
                            sourceColor = Color.random
                        }
                )
            
            // 目标视图
            Circle()
                .fill(targetColor)
                .frame(width: 100, height: 100)
                .onDrop(of: [.color], delegate: ColorDropDelegate(color: $targetColor))
        }
    }
}

struct ColorDropDelegate: DropDelegate {
    @Binding var color: Color
    
    func performDrop(info: DropInfo) -> Bool {
        // 当拖放操作完成时，更新目标颜色为源颜色
        color = info.itemProviders(for: [.color]).first?.loadObject(ofClass: UIColor.self, completionHandler: { (provider, error) in
            if let color = provider as? UIColor {
                DispatchQueue.main.async {
                    self.color = Color(color)
                }
            }
        }) as? Color ?? .gray
        
        return true
    }
    
    func validateDrop(info: DropInfo) -> Bool {
        // 验证拖放操作是否可接受颜色
        return info.hasItemsConforming(to: [.color])
    }
}

extension Color {
    static var random: Color {
        return Color(red: .random(in: 0...1),
                     green: .random(in: 0...1),
                     blue: .random(in: 0...1))
    }
}

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