Swiftui 如何使拖放viewmodifier接受任何对象

我已经创建了一个拖放viewmodifier，它可以按预期工作，但现在我想让它接受任何对象。我可以添加到所有函数、结构和视图修饰符中，但当我尝试将其添加到我的singleton类中时，我得到了“泛型类型中不支持的静态存储属性”

我需要singleton类，这样我就可以将.dropObjectOutside viewmodifier放在视图层次结构中的任何位置，所以我尝试将ID向下转换为字符串，但我似乎无法实现这一点

有没有一种方法可以使这段代码接受任何对象

import SwiftUI

// I want this to be any object
struct StopContent: Identifiable {
    var id: String = UUID().uuidString
}

// Singleton class to hold drag state
class DragToReorderController: ObservableObject {

    // Make it a singleton, so it can be accessed from any view
    static let shared = DragToReorderController()
    private init() { }

    @Published var draggedID: String? // How do I make this a T.ID or downcast T.ID to string everywhere else?
    @Published var dragActive:Bool = false

}


// Add ViewModifier to view
extension View {

    func dragToReorder(_ item: StopContent, array: Binding<[StopContent]>) -> some View {
        self.modifier(DragToReorderObject(sourceItem: item, contentArray: array))
    }

    func dropOutside() -> some View {
        self.onDrop(of: [UTType.text], delegate: DropObjectOutsideDelegate())
    }
}


import UniformTypeIdentifiers

// MARK: View Modifier
struct DragToReorderObject: ViewModifier {

    let sourceItem: StopContent
    @Binding var contentArray: [StopContent]

    @ObservedObject private var dragReorder = DragToReorderController.shared

    func body(content: Content) -> some View {
        content
        .onDrag {
            dragReorder.draggedID = sourceItem.id
            dragReorder.dragActive = false
            return NSItemProvider(object: String(sourceItem.id) as NSString)
        }
        .onDrop(of: [UTType.text], delegate: DropObjectDelegate(sourceItem: sourceItem, listData: $contentArray, draggedItem: $dragReorder.draggedID, dragActive: $dragReorder.dragActive))
        .onChange(of: dragReorder.dragActive, perform: { value in
            if value == false {
                // Drag completed
            }
        })
        .opacity(dragReorder.draggedID == sourceItem.id && dragReorder.dragActive ? 0 : 1)
            
    }
}

// MARK: Drop and reorder
struct DropObjectDelegate: DropDelegate {

    let sourceItem: StopContent
    @Binding var listData: [StopContent]
    @Binding var draggedItem: String?
    @Binding var dragActive: Bool


    func dropEntered(info: DropInfo) {
    
        if draggedItem == nil { draggedItem = sourceItem.id }
    
        dragActive = true
    
        // Make sure the dragged item has moved and that it still exists
        if sourceItem.id != draggedItem {
            if let draggedItemValid = draggedItem {
                if let from = listData.firstIndex(where: { $0.id == draggedItemValid } ) {
                
                    // If that is true, move it to the new location
                    let to = listData.firstIndex(where: { $0.id == sourceItem.id } )!
                
                    if listData[to].id != draggedItem! {
                        listData.move(fromOffsets: IndexSet(integer: from),
                            toOffset: to > from ? to + 1 : to)
                    }
                }
            }
        }
    }

    func dropUpdated(info: DropInfo) -> DropProposal? {
        return DropProposal(operation: .move)
    }

    func performDrop(info: DropInfo) -> Bool {
        dragActive = false
        draggedItem = nil
        return true
    }

}


// MARK: Drop and cancel
struct DropObjectOutsideDelegate: DropDelegate {

    // Using a singleton so we can drop anywhere
    @ObservedObject private var dragReorder = DragToReorderController.shared
    
    func dropEntered(info: DropInfo) {
        dragReorder.dragActive = true
    }

    func performDrop(info: DropInfo) -> Bool {
        dragReorder.dragActive = false
        dragReorder.draggedID = nil
        return true
    }
}

导入快捷界面
//我希望这是任何对象
struct StopContent:可识别{
变量id:String=UUID（）.UUIString
}
//保持拖动状态的单例类
类DragToReorderController:observeObject{
//将其设置为单例，以便可以从任何视图访问它
静态let shared=DragToReorderController（）
私有init（）{}
@已发布的var draggedID:String？//如何将其作为T.ID或向下转换的T.ID，以便在其他地方使用String？
@已发布变量dragActive:Bool=false
}
//将ViewModifier添加到视图
扩展视图{
func dragToReorder（uItem:StopContent，array:Binding）->一些视图{
修饰符（DragToReorderObject（sourceItem:item，contentArray:array））
}
func dropOutside（）->一些视图{
self.onDrop（属于：[UTType.text]，委托：DropObjectOutsideDelegate（））
}
}
导入UniformTypeIdentifiers
//标记：视图修改器
结构DragToReorderObject:ViewModifier{
让sourceItem:StopContent
@绑定变量contentArray:[StopContent]
@ObservedObject private var dragReorder=DragToReorderController.shared
func正文（内容：内容）->某些视图{
内容
昂德拉格先生{
dragReorder.draggedID=sourceItem.id
dragReorder.dragActive=false
返回NSItemProvider（对象：字符串（sourceItem.id）作为NSString）
}
.onDrop（of:[UTType.text]，委托：DropObjectDelegate（sourceItem:sourceItem，listData:$contentArray，DragEdItem:$DrageOrder.DrageDid，dragActive:$DrageOrder.dragActive））
.onChange（of:dragReorder.dragActive，执行：{中的值
如果值==false{
//拖动完成
}
})
.opacity（dragReorder.draggedID==sourceItem.id&&dragReorder.dragActive？0:1）
}
}
//标记：删除并重新排序
结构DropObjectDelegate:DropDelegate{
让sourceItem:StopContent
@绑定变量listData:[StopContent]
@绑定变量draggedItem:字符串？
@绑定变量dragActive:Bool
func dropEntered（信息：DropInfo）{
如果draggedItem==nil{draggedItem=sourceItem.id}
dragActive=true
//确保拖动的项目已移动且仍存在
如果sourceItem.id！=draggedItem{
如果让draggedItemValid=draggedItem{
如果let from=listData.firstIndex（其中：{$0.id==draggedItemValid}）{
//如果这是真的，请将其移动到新位置
let to=listData.firstIndex（其中：{$0.id==sourceItem.id}）！
如果listData[to].id！=draggedItem{
move（fromOffsets:IndexSet（integer:from），
toOffset:to>from？to+1:to）
}
}
}
}
}
func DropUpdate（信息：DropInfo）->DropProposal{
返回建议（操作：。移动）
}
func performDrop（信息：DropInfo）->Bool{
dragActive=false
draggedItem=零
返回真值
}
}
//马克：放弃并取消
结构DropObjectOutsideDelegate:DropDelegate{
//使用单人床，这样我们可以在任何地方下车
@ObservedObject private var dragReorder=DragToReorderController.shared
func dropEntered（信息：DropInfo）{
dragReorder.dragActive=true
}
func performDrop（信息：DropInfo）->Bool{
dragReorder.dragActive=false
dragReorder.draggedID=nil
返回真值
}
}

为此，必须在所有位置添加

可识别的
通用约束。另外，将Int用于
draggedID
而不是String

这是演示代码

// Singleton class to hold drag state
class DragToReorderController: ObservableObject {

    // Make it a singleton, so it can be accessed from any view
    static let shared = DragToReorderController()
    private init() { }

    @Published var draggedID: Int?
    @Published var dragActive: Bool = false
}


// Add ViewModifier to view
extension View {

    func dragToReorder<T: Identifiable>(_ item: T, array: Binding<[T]>) -> some View {
        self.modifier(DragToReorderObject(sourceItem: item, contentArray: array))
    }

    func dropOutside() -> some View {
        self.onDrop(of: [UTType.text], delegate: DropObjectOutsideDelegate())
    }
}


import UniformTypeIdentifiers

// MARK: View Modifier
struct DragToReorderObject<T: Identifiable>: ViewModifier {
    
    let sourceItem: T
    @Binding var contentArray: [T]
    
    @ObservedObject private var dragReorder = DragToReorderController.shared
    
    func body(content: Content) -> some View {
        content
            .onDrag {
                dragReorder.draggedID = sourceItem.id.hashValue
                dragReorder.dragActive = false
                return NSItemProvider(object: String(sourceItem.id.hashValue) as NSString)
            }
            .onDrop(of: [UTType.text], delegate: DropObjectDelegate(sourceItem: sourceItem, listData: $contentArray, draggedItem: $dragReorder.draggedID, dragActive: $dragReorder.dragActive))
            .onChange(of: dragReorder.dragActive, perform: { value in
                if value == false {
                    // Drag completed
                }
            })
            .opacity((dragReorder.draggedID == sourceItem.id.hashValue) && dragReorder.dragActive ? 0 : 1)
    }
}

// MARK: Drop and reorder
struct DropObjectDelegate<T: Identifiable>: DropDelegate {

    let sourceItem: T
    @Binding var listData: [T]
    @Binding var draggedItem: Int?
    @Binding var dragActive: Bool


    func dropEntered(info: DropInfo) {
    
        if draggedItem == nil { draggedItem = sourceItem.id.hashValue }
    
        dragActive = true
    
        // Make sure the dragged item has moved and that it still exists
        if sourceItem.id.hashValue != draggedItem {
            if let draggedItemValid = draggedItem {
                if let from = listData.firstIndex(where: { $0.id.hashValue == draggedItemValid } ) {
                
                    // If that is true, move it to the new location
                    let to = listData.firstIndex(where: { $0.id == sourceItem.id } )!
                
                    if listData[to].id.hashValue != draggedItem! {
                        listData.move(fromOffsets: IndexSet(integer: from),
                            toOffset: to > from ? to + 1 : to)
                    }
                }
            }
        }
    }

    func dropUpdated(info: DropInfo) -> DropProposal? {
        return DropProposal(operation: .move)
    }

    func performDrop(info: DropInfo) -> Bool {
        dragActive = false
        draggedItem = nil
        return true
    }

}


// MARK: Drop and cancel
struct DropObjectOutsideDelegate: DropDelegate {

    // Using a singleton so we can drop anywhere
    @ObservedObject private var dragReorder = DragToReorderController.shared
    
    func dropEntered(info: DropInfo) {
        dragReorder.dragActive = true
    }

    func performDrop(info: DropInfo) -> Bool {
        dragReorder.dragActive = false
        dragReorder.draggedID = nil
        return true
    }
}

//保持拖动状态的单例类
类DragToReorderController:observeObject{
//将其设置为单例，以便可以从任何视图访问它
静态let shared=DragToReorderController（）
私有init（）{}
@发布变量：Int？
@已发布变量dragActive:Bool=false
}
//将ViewModifier添加到视图
扩展视图{
func dragToReorder（uu项：T，数组：Binding）->一些视图{
修饰符（DragToReorderObject（sourceItem:item，contentArray:array））
}
func dropOutside（）->一些视图{
self.onDrop（属于：[UTType.text]，委托：DropObjectOutsideDelegate（））
}
}
导入UniformTypeIdentifiers
//标记：视图修改器
结构DragToReorderObject:ViewModifier{
让sourceItem:T
@绑定变量contentArray:[T]
@ObservedObject private var dragReorder=DragToReorderController.shared
func正文（内容：内容）->某些视图{
内容
昂德拉格先生{
dragReorder.draggedID=sourceItem.id.hashValue
dragReorder.dragActive=false
返回NSItemProvider（对象：字符串（sourceItem.id.hashValue）作为NSString）
}
.onDrop（of:[UTType.text]，委托：DropObjectDelegate（sourceItem:sourceItem，listData:$contentArray，DragEdItem:$DrageOrder.DrageDid，dragActive:$DrageOrder.dragActive））
.onChange（of:dragReorder.dragActive，执行：{中的值
如果值==false{
//拖动完成
}
})
.opacity（（dragReorder.draggedID==sourceItem.id.hashValue）&&dragReo