c# - 将文件拖放到程序中

Question

我正在使用 MonoDevelop 工具。
我想用 GTK# 编写如下程序；

1. 用户拖拽文件到程序的listView, tableView 或者其他
2.拖拽文件列表打印在程序窗口

但我几乎是 GTK# 的新手，并且不知道如何拖放，
所以我搜索了有关它的信息并找到了如下链接。
http://developer.gnome.org/gtkmm-tutorial/3.0/sec-dnd-example.html.en

这是我试图使程序链接建议的代码
(此链接解释了 C++ 中的拖放操作，我不得不像 C# 那样进行操作)

使用 Gtk； 使用系统； 使用系统集合； 使用 System.Collections.Generic；

namespace DragAndDrop
{
    public class SharpApp: Window
    {
        Button btnDrag;
        Label lblDrop;
        HBox hbox;

        public SharpApp (): base("Title")
        {
            btnDrag = new Button("Drag Here");
            lblDrop = new Label("Drop Here");
            hbox = new HBox();

            SetDefaultSize(250,200);
            SetPosition (Gtk.WindowPosition.Center);
            DeleteEvent += (o, args) => Application.Quit ();

            // Targets
            List<TargetEntry> list
                = new List<TargetEntry> ();
            list.Add (new TargetEntry
                      ("STRING", TargetFlags.Widget, 0));
            list.Add (new TargetEntry
                      ("text/plain", TargetFlags.Widget, 0));

            // Drag site -----
            // Make btnDrag a DnD drag source:
            TargetEntry[] entries = list.ToArray();
            TargetEntry[] se = new TargetEntry[] {entries[0]};

            Drag.SourceSet (btnDrag, Gdk.ModifierType.ModifierMask,
                            se, Gdk.DragAction.Copy);

            // Connect signals
            btnDrag.DragDataGet += delegate
                (object o, DragDataGetArgs args) {
                Console.WriteLine ("Test");
                OnDragDataGet(args.Context,
                              args.SelectionData,
                              args.Info,
                              args.Time);
            };

            hbox.PackStart (btnDrag);

            // Drop site -----
            // Make lblDrop a DnD drop destination:
            TargetEntry[] de = new TargetEntry[] {entries[1]};

            Drag.DestSet (lblDrop, DestDefaults.Drop,
                          de, Gdk.DragAction.Copy);


            // Connect signals
            lblDrop.DragDataReceived += delegate
                (object o, DragDataReceivedArgs args) {
                Console.WriteLine ("Test");
                OnDragDataReceived(args.Context,
                                   args.X,
                                   args.Y,
                                   args.SelectionData,
                                   args.Info,
                                   args.Time);
            };

            // hbox
            hbox.PackStart (lblDrop);

            Add (hbox);

            ShowAll ();
        }

        // event handlers
        protected override void OnDragDataGet
            (Gdk.DragContext context, SelectionData sdata,
             uint info, uint time)
        {
            Console.WriteLine ("OnDragDataGet");

            string tmp = "I'm data!";
            byte[] b = new byte[tmp.Length];
            for (int i=0; i<tmp.Length; ++i)
                b[i] = (byte)tmp[i];

            sdata.Set(sdata.Target, 8, b, tmp.Length);
        }
        protected override void OnDragDataReceived
            (Gdk.DragContext context, int x, int y,
             SelectionData sdata, uint info, uint time)
        {
            Console.WriteLine ("OnDragDataReceived");

            int length = sdata.Length;
            if ((length>=0) && (sdata.Format==8))
            {
                Console.WriteLine ("Received \"{0}\" in label",
                                   sdata.Data.ToString());
            }

            Drag.Finish (context, false, false, time);
        }

        // main
        public static void Main (string[] args)
        {
            Application.Init ();
            new SharpApp();
            Application.Run ();
        }
    }
}

但结果告诉我我可能错了..我以为按钮会被移动
当我拖动它时，但按钮根本没有移动。有没有人能够解决我的问题？

Answer 1

以下示例将放置在其上的文件的完整路径打印到标签(称为 lblPath)中:

public partial class MainWindow: Gtk.Window
{
    /** Add a label to your project called lblPath **/
    public MainWindow () : base (Gtk.WindowType.Toplevel)
    {
        Build ();
        //media type we'll accept
        Gtk.TargetEntry [  ] target_table = 
            new TargetEntry [  ] {
            new TargetEntry ("text/uri-list", 0, 0),
            new TargetEntry ("application/x-monkey", 0, 1),
        };
        Gtk.Drag.DestSet (lblPath, DestDefaults.All, target_table, Gdk.DragAction.Copy);
        lblPath.DragDataReceived += new Gtk.DragDataReceivedHandler(OnLabelDragDataReceived);
    }

    void OnLabelDragDataReceived (object sender, Gtk.DragDataReceivedArgs args)
    {
        if (args.SelectionData.Length > 0) {
            byte[] data = args.SelectionData.Data;
            string files = System.Text.Encoding.UTF8.GetString (data);
            string file;
            string[] fileArray = files.Split ('\n');
            for (int i = 0; i < fileArray.Length - 1; i++) { //the last element is empty
                file = fileArray [i].Replace ("\r", "");
                if (file.StartsWith("file://"))
                    file = file.Substring(7); //for Windows should be 8
                lblPath.Text += file + "\n";
            }
        }
    }
}