如何在不禁用列表项的命中测试的情况下启用对列表项的选择？

Posted 2023-02-23

【中文标题】如何在不禁用列表项的命中测试的情况下启用对列表项的选择？

【英文标题】：How do you enable selection on items in a list without disabling hit testing on the list items?

【发布时间】：2021-03-30 20:32:50

【问题描述】：

我正在尝试创建一个文件浏览器，用户可以在其中将我的 LibraryView 中的条目拖放到主视图上以显示它们。同样有效的是上下文菜单，用户可以在其中右键单击以删除或编辑文件上的首选项。问题是，如果我在文件的文本标签上禁用命中测试，我无法拖放文件，但选择有效...如果我启用命中测试，我无法单击文件的文本标签选择它。这是我的代码，任何帮助将不胜感激......

struct LibraryView: View 
    @ObservedObject var viewModel = LibraryViewModel()
    var body: some View 
        List(selection: $viewModel.selectedNodes) 
            ForEach(viewModel.nodes, id: \.self)  node in
                if let childrenNodes = node.childrenValues, childrenNodes.count > 0 
                    Section(header: Text(node.displayName)) 
                        ForEach(childrenNodes, id: \.self)  childNode in
                            LibraryNodeChildView(node: childNode).contextMenu 
                                Button(action:
                                    store.dispatch(LibraryAction.removeNode(childNode))
                                    store.dispatch(LibraryThunkCreatorImpl().persistLibraryState())
                                )
                                    HStack 
                                        Text("Delete")
                                        Image(systemName: "trash")
                                    
                                
                                Button(action:
                                    
                                )
                                    HStack 
                                        Text("Edit Preferences")
                                        Image(systemName: "gear")
                                    
                                
                            
                        
                    
                
            
        .listStyle(SidebarListStyle())
        .onAppear() 
            store.dispatch(LibraryThunkCreatorImpl().loadLibraryState())
        .onDrop(of: ["public.url","public.file-url"], isTargeted: nil)  (items) -> Bool in
            if let item = items.first 
                if let identifier = item.registeredTypeIdentifiers.first 
                    print("onDrop with identifier = \(identifier)")
                    if identifier == "public.url" || identifier == "public.file-url" 
                        item.loadItem(forTypeIdentifier: identifier, options: nil)  (urlData, error) in
                            DispatchQueue.main.async 
                                if let urlData = urlData as? Data 
                                    let url = NSURL(absoluteURLWithDataRepresentation: urlData, relativeTo: nil) as URL
                                    let thunk = LibraryThunkCreatorImpl().createAddNodeThunk(url: url)
                                    store.dispatch(thunk)
                                
                            
                        
                    
                
                return true
             else 
                print("item not here")
                return false
            
        
    


struct LibraryNodeChildView: View 
    let node: LibraryNode
    var body: some View 
        HStack 
            if let image = node.image 
                Image(nsImage: image)
                    .resizable()
                    .scaledToFit()
                    .frame(width: 15, height: 15)
            
            Text(verbatim: node.displayName).onDrag 
                NSItemProvider(object: node.url as NSURL)                
            .allowsHitTesting(false)
            .font(.subheadline)
        
    

【参考方案1】：

如here 所述，解决方案是将拖放绑定到项目容器，并将上下文菜单绑定到容器内的项目。

HStack 
   Text(verbatim: node.displayName)
       .contextMenu 
           // handle context menu
       
   
   .onDrag 
       // handle drag