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这是我在这里的第一篇文章，在这个问候网站上。我是一位经验丰富的 C#、.Net 和 Mono 用户，但在 MonoMac 中是 Noob，我正在尝试编写一个应用程序，它接收 NSView 上的文件夹并使用其路径来处理文件夹内的文件......

MonoMac 框架没有实现draggingEntered:, draggingUpdated:, draggingExited:, prepareForDragOperation:, performDragOperation:, concludeDragOperation: and draggingEnded:

所以我尝试自己实现它们：

[Register("TargetView")] 
public class TargetView:NSView
{
    private static IntPtr selDraggingEntered = Selector.GetHandle ("draggingEntered:");

    private static IntPtr selDraggingUpdated = Selector.GetHandle ("draggingUpdated:");

    private static IntPtr selDraggingExited = Selector.GetHandle ("draggingExited:");

    private static IntPtr selPrepareForDragOperation = Selector.GetHandle ("prepareForDragOperation:");

    private static IntPtr selPerformDragOperation = Selector.GetHandle ("performDragOperation:");

    private static IntPtr selConcludeDragOperation = Selector.GetHandle ("concludeDragOperation:");

    private static IntPtr selDraggingEnded = Selector.GetHandle ("draggingEnded:");

    public TargetView():base(){
    }

    public TargetView(NSCoder coder):base(coder){
    }

    public TargetView(NSObjectFlag t):base(t){
    }

    public TargetView(IntPtr handle):base(handle){
    }

    public TargetView(RectangleF frameRect):base(frameRect){
    }

    [Export ("draggingEntered:")]
    public virtual NSDragOperation DraggingEntered (NSDraggingInfo sender)
    {
        if (sender == null)
        {
            throw new ArgumentNullException ("sender");
        }
        if (this.IsDirectBinding)
        {
            return (NSDragOperation)Messaging.int_objc_msgSend_int (base.Handle, TargetView.selDraggingEntered, (int)sender.DraggingSourceOperationMask);
        }
        return (NSDragOperation)Messaging.int_objc_msgSendSuper_int (base.Handle, TargetView.selDraggingEntered, (int)sender.DraggingSourceOperationMask);
    }

    [Export ("draggingUpdated:")]
    public virtual NSDragOperation DraggingUpdated (NSDraggingInfo sender)
    {
        if (sender == null)
        {
            throw new ArgumentNullException ("sender");
        }
        if (this.IsDirectBinding)
        {
            return (NSDragOperation)Messaging.int_objc_msgSend_int (base.Handle, TargetView.selDraggingUpdated, (int)sender.DraggingSourceOperationMask);
        }
        return (NSDragOperation)Messaging.int_objc_msgSendSuper_int (base.Handle, TargetView.selDraggingUpdated, (int)sender.DraggingSourceOperationMask);
    }

    [Export ("draggingExited:")]
    public virtual void DraggingExited (NSDraggingInfo sender)
    {
        if (sender == null)
        {
            throw new ArgumentNullException ("sender");
        }
        if (this.IsDirectBinding)
        {
            Messaging.void_objc_msgSend_int (base.Handle, TargetView.selDraggingExited, (int)sender.DraggingSourceOperationMask);
        }
        Messaging.void_objc_msgSendSuper_int (base.Handle, TargetView.selDraggingExited, (int)sender.DraggingSourceOperationMask);
    }

    [Export ("prepareForDragOperation:")]
    public virtual bool PrepareForDragOperation (NSDraggingInfo sender)
    {
        if (sender == null)
        {
            throw new ArgumentNullException ("sender");
        }
        if (this.IsDirectBinding)
        {
            return Messaging.bool_objc_msgSend_int (base.Handle, TargetView.selPrepareForDragOperation, (int)sender.DraggingSourceOperationMask);
        }
        return Messaging.bool_objc_msgSendSuper_int (base.Handle, TargetView.selPrepareForDragOperation, (int)sender.DraggingSourceOperationMask);
    }

    [Export ("performDragOperation:")]
    public virtual bool PerformDragOperation (NSDraggingInfo sender)
    {
        if (sender == null)
        {
            throw new ArgumentNullException ("sender");
        }
        if (this.IsDirectBinding)
        {
            return Messaging.bool_objc_msgSend_int (base.Handle, TargetView.selPerformDragOperation, (int)sender.DraggingSourceOperationMask);
        }
        return Messaging.bool_objc_msgSendSuper_int (base.Handle, TargetView.selPerformDragOperation, (int)sender.DraggingSourceOperationMask);
    }

    [Export ("concludeDragOperation:")]
    public virtual void ConcludeDragOperation (NSDraggingInfo sender)
    {
        if (sender == null)
        {
            throw new ArgumentNullException ("sender");
        }
        if (this.IsDirectBinding)
        {
            Messaging.void_objc_msgSend_int (base.Handle, TargetView.selConcludeDragOperation, (int)sender.DraggingSourceOperationMask);
        }
        Messaging.void_objc_msgSendSuper_int (base.Handle, TargetView.selConcludeDragOperation, (int)sender.DraggingSourceOperationMask);
    }

    [Export ("draggingEnded:")]
    public virtual void DraggingEnded (NSDraggingInfo sender)
    {
        if (sender == null)
        {
            throw new ArgumentNullException ("sender");
        }
        if (this.IsDirectBinding)
        {
            Messaging.void_objc_msgSend_int (base.Handle, TargetView.selDraggingEnded, (int)sender.DraggingSourceOperationMask);
        }
        Messaging.void_objc_msgSendSuper_int (base.Handle, TargetView.selDraggingEnded, (int)sender.DraggingSourceOperationMask);
    }
}

但是这些方法不会被调用！

我也尝试过，RegisterForDraggedTypes但我不知道将什么作为类型传递给字符串数组！

请帮我弄清楚。我一直在谷歌搜索 48 ！

4

2 回答 2

7

我最终通过做一些测试并将它们与拖放会话中的 Apple 文档进行比较，自己找到了问题的答案。

这是我使用的来源，它的世界就像一个魅力：

[Register("DropTargetView")]
public class DropTargetView:NSView
{
    public DropTargetView(IntPtr handle):base(handle){

        RegisterForDraggedTypes(new string[]{"NSFilenamesPboardType"});
    }

    [Export ("draggingEntered:")]
    public NSDragOperation DraggingEntered (NSDraggingInfo sender)
    {
        NSPasteboard pasteboard = sender.DraggingPasteboard;

        bool typeExists = (Array.IndexOf(pasteboard.Types,"NSFilenamesPboardType") >= 0);

        if(typeExists)
        {
            return NSDragOperation.Link;
        }
        else
        {
            return NSDragOperation.None;
        }
    }

    [Export ("performDragOperation:")]
    public bool PerformDragOperation (NSDraggingInfo sender)
    {
        NSPasteboard pasteboard = sender.DraggingPasteboard;

        bool typeExists = (Array.IndexOf(pasteboard.Types,"NSFilenamesPboardType") >= 0);

        if(typeExists)
        {
            NSPasteboardItem[] pasteboardItems = pasteboard.PasteboardItems;

            for(int i = 0; i < pasteboardItems.Length; i++)
            {
                string urlStr = pasteboardItems[i].GetStringForType("public.file-url");

                NSUrl url = new NSUrl (urlStr);

                string filePath = url.Path;

                Console.WriteLine(filePath);
            }

            return true;
        }
        else
        {
            return false;
        }
    }
}

这里有一点解释：

我首先发现 Custom 类正在使用 Handle 进行实例化，因此我需要在该方法中注册 RegisterForDraggedTypes。然后，我使用 Apple 文档的示例来跟踪 RegisterForDraggedTypes 字符串 const 并从中取出“RegisterForDraggedTypes”，将其用作文件路径的注册值。并且使用 Apple 文档的示例发现需要导出的唯一 2 个方法是 draggingEntered: 和 performDragOperation:，所以我只是导出它们并自己返回预期值，而不是向 Cocoa 发送消息以返回值，现在一切正常. 从 NSPasteboardItems 中提取文件 URL 所需的 UTI 是 Apple 定义为“public.file-url”的 UTI，所以我用它来获取以下形式的路径：

file://localhost/PathToFileOrFolder/FileOrFolderName[/ 如果是文件夹]

希望它可以帮助别人。

更新（2015-09-30）：

我已将@M_K 提到的更改应用于我的代码。

于 2012-03-14T10:30:23.153 回答
0

我注意到，使用最新版本的 MonoMac / Xamarin，调用pasteboardItems[i].GetStringForType("public.file-url")而不是文件路径，它返回一个 URL：

文件：///.file/id=...

要获取文件路径，您需要执行以下操作：

string urlStr = pasteboardItems[i].GetStringForType("public.file-url");
NSUrl url = new NSUrl (urlStr);
string filePath = url.Path;
于 2015-09-23T05:14:46.217 回答