blocks|key|1201265|text|这通常由GiveFeedback事件处理。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1201266|entityMap^0|4|C|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

That's usually handled by the <code>GiveFeedback</code> event.

blocks|key|986851|text|我想我应该回来自己回答这个问题，因为我最终确实让它工作了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|986852|我创建了一个具有以下函数的CursorUtil类：|986853|public+struct+IconInfo+{
++++public+bool+fIcon;
++++public+int+xHotspot;
++++public+int+yHotspot;
++++public+IntPtr+hbmMask;
++++public+IntPtr+hbmColor;
}

public+class+CursorUtil+{
++++[DllImport("user32.dll")]
++++public+static+extern+IntPtr+CreateIconIndirect(ref+IconInfo+icon);

++++[DllImport("user32.dll")]
++++[return:+MarshalAs(UnmanagedType.Bool)]
++++public+static+extern+bool+GetIconInfo(IntPtr+hIcon,+ref+IconInfo+pIconInfo);

++++[DllImport("gdi32.dll")]
++++public+static+extern+bool+DeleteObject(IntPtr+handle);

++++[DllImport("user32.dll",+CharSet+=+CharSet.Auto)]
++++extern+static+bool+DestroyIcon(IntPtr+handle);

++++//+Based+on+the+article+and+comments+here:
++++//+http://www.switchonthecode.com/tutorials/csharp-tutorial-how-to-use-custom-cursors
++++//+Note+that+the+returned+Cursor+must+be+disposed+of+after+use,+or+you'll+leak+memory!
++++public+static+Cursor+CreateCursor(Bitmap+bm,+int+xHotspot,+int+yHotspot)+{
++++++++IntPtr+cursorPtr;
++++++++IntPtr+ptr+=+bm.GetHicon();
++++++++IconInfo+tmp+=+new+IconInfo();
++++++++GetIconInfo(ptr,+ref+tmp);
++++++++tmp.xHotspot+=+xHotspot;
++++++++tmp.yHotspot+=+yHotspot;
++++++++tmp.fIcon+=+false;
++++++++cursorPtr+=+CreateIconIndirect(ref+tmp);

++++++++if+(tmp.hbmColor+!=+IntPtr.Zero)+DeleteObject(tmp.hbmColor);
++++++++if+(tmp.hbmMask+!=+IntPtr.Zero)+DeleteObject(tmp.hbmMask);
++++++++if+(ptr+!=+IntPtr.Zero)+DestroyIcon(ptr);

++++++++return+new+Cursor(cursorPtr);
++++}

++++public+static+Bitmap+AsBitmap(Control+c)+{
++++++++Bitmap+bm+=+new+Bitmap(c.Width,+c.Height);
++++++++c.DrawToBitmap(bm,+new+Rectangle(0,+0,+c.Width,+c.Height));
++++++++return+bm;
++++}|code-block|syntax|javascript|986854|然后我写了一个Drag类(也不是面向对象的，但我认为在桌面应用程序中一次只能拖动一件事)。下面是其中一些代码：|986855|++++public+static+void+StartDragging(Control+c)+{
++++++++Dragged+=+c;
++++++++DisposeOldCursors();
++++++++Bitmap+bm+=+CursorUtil.AsBitmap(c);
++++++++DragCursorMove+=+CursorUtil.CreateCursor((Bitmap)bm.Clone(),+DragStart.X,+DragStart.Y);++++++
++++++++DragCursorLink+=+CursorUtil.CreateCursor((Bitmap)bm.Clone(),+DragStart.X,+DragStart.Y);++++++
++++++++DragCursorCopy+=+CursorUtil.CreateCursor(CursorUtil.AddCopySymbol(bm),+DragStart.X,+DragStart.Y);
++++++++DragCursorNo+=+CursorUtil.CreateCursor(CursorUtil.AddNoSymbol(bm),+DragStart.X,+DragStart.Y);
++++++++//Debug.WriteLine("Starting+drag");
++++}+++

++++//+This+gets+called+once+when+we+move+over+a+new+control,
++++//+or+continuously+if+that+control+supports+dropping.
++++public+static+void+UpdateCursor(object+sender,+GiveFeedbackEventArgs+fea)+{
++++++++//Debug.WriteLine(MainForm.MousePosition);
++++++++fea.UseDefaultCursors+=+false;
++++++++//Debug.WriteLine("effect+=+"+%2B+fea.Effect);
++++++++if+(fea.Effect+==+DragDropEffects.Move)+{
++++++++++++Cursor.Current+=+DragCursorMove;

++++++++}+else+if+(fea.Effect+==+DragDropEffects.Copy)+{
++++++++++++Cursor.Current+=+DragCursorCopy;

++++++++}+else+if+(fea.Effect+==+DragDropEffects.None)+{
++++++++++++Cursor.Current+=+DragCursorNo;

++++++++}+else+if+(fea.Effect+==+DragDropEffects.Link)+{
++++++++++++Cursor.Current+=+DragCursorLink;

++++++++}+else+{
++++++++++++Cursor.Current+=+DragCursorMove;
++++++++}
++++}|986856|您可以在设置控件时使用这些方法，例如在构造函数中：|986857|GiveFeedback+%2B=+new+GiveFeedbackEventHandler(Drag.UpdateCursor);|986858|在这种方法中：|986859|++++protected+override+void+OnMouseMove(MouseEventArgs+mea)+{
++++++++if+(Drag.IsDragging(mea))+{
++++++++++++Drag.StartDragging(this);
++++++++++++DragDropEffects+dde+=+DoDragDrop(Plan,+DragDropEffects.Move+%7C+DragDropEffects.Copy);
++++++++++++Drag.StopDragging();
++++++++}
++++}|986860|entityMap^0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|X|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|10|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|11|8|@]|9|@]|A|$]]|$1|O|3|P|5|F|7|12|8|@]|9|@]|A|$G|H]]|$1|Q|3|R|5|6|7|13|8|@]|9|@]|A|$]]|$1|S|3|T|5|F|7|14|8|@]|9|@]|A|$G|H]]|$1|U|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|V|$]]

I thought I should come back and answer this myself, since I did get it working eventually.

I created a CursorUtil class with these functions:

<pre><code>public struct IconInfo {
 public bool fIcon;
 public int xHotspot;
 public int yHotspot;
 public IntPtr hbmMask;
 public IntPtr hbmColor;
}

public class CursorUtil {
 [DllImport("user32.dll")]
 public static extern IntPtr CreateIconIndirect(ref IconInfo icon);

 [DllImport("user32.dll")]
 [return: MarshalAs(UnmanagedType.Bool)]
 public static extern bool GetIconInfo(IntPtr hIcon, ref IconInfo pIconInfo);

 [DllImport("gdi32.dll")]
 public static extern bool DeleteObject(IntPtr handle);

 [DllImport("user32.dll", CharSet = CharSet.Auto)]
 extern static bool DestroyIcon(IntPtr handle);

 // Based on the article and comments here:
 // http://www.switchonthecode.com/tutorials/csharp-tutorial-how-to-use-custom-cursors
 // Note that the returned Cursor must be disposed of after use, or you'll leak memory!
 public static Cursor CreateCursor(Bitmap bm, int xHotspot, int yHotspot) {
 IntPtr cursorPtr;
 IntPtr ptr = bm.GetHicon();
 IconInfo tmp = new IconInfo();
 GetIconInfo(ptr, ref tmp);
 tmp.xHotspot = xHotspot;
 tmp.yHotspot = yHotspot;
 tmp.fIcon = false;
 cursorPtr = CreateIconIndirect(ref tmp);

 if (tmp.hbmColor != IntPtr.Zero) DeleteObject(tmp.hbmColor);
 if (tmp.hbmMask != IntPtr.Zero) DeleteObject(tmp.hbmMask);
 if (ptr != IntPtr.Zero) DestroyIcon(ptr);

 return new Cursor(cursorPtr);
 }

 public static Bitmap AsBitmap(Control c) {
 Bitmap bm = new Bitmap(c.Width, c.Height);
 c.DrawToBitmap(bm, new Rectangle(0, 0, c.Width, c.Height));
 return bm;
 }
</code></pre>

Then I wrote a Drag class (also not object-oriented, alas, but I figured you can only drag one thing at a time in a desktop app). Here is a bit of that code:

<pre><code> public static void StartDragging(Control c) {
 Dragged = c;
 DisposeOldCursors();
 Bitmap bm = CursorUtil.AsBitmap(c);
 DragCursorMove = CursorUtil.CreateCursor((Bitmap)bm.Clone(), DragStart.X, DragStart.Y); 
 DragCursorLink = CursorUtil.CreateCursor((Bitmap)bm.Clone(), DragStart.X, DragStart.Y); 
 DragCursorCopy = CursorUtil.CreateCursor(CursorUtil.AddCopySymbol(bm), DragStart.X, DragStart.Y);
 DragCursorNo = CursorUtil.CreateCursor(CursorUtil.AddNoSymbol(bm), DragStart.X, DragStart.Y);
 //Debug.WriteLine("Starting drag");
 } 

 // This gets called once when we move over a new control,
 // or continuously if that control supports dropping.
 public static void UpdateCursor(object sender, GiveFeedbackEventArgs fea) {
 //Debug.WriteLine(MainForm.MousePosition);
 fea.UseDefaultCursors = false;
 //Debug.WriteLine("effect = " + fea.Effect);
 if (fea.Effect == DragDropEffects.Move) {
 Cursor.Current = DragCursorMove;

 } else if (fea.Effect == DragDropEffects.Copy) {
 Cursor.Current = DragCursorCopy;

 } else if (fea.Effect == DragDropEffects.None) {
 Cursor.Current = DragCursorNo;

 } else if (fea.Effect == DragDropEffects.Link) {
 Cursor.Current = DragCursorLink;

 } else {
 Cursor.Current = DragCursorMove;
 }
 }
</code></pre>

You can use these methods when you set up your controls, for example in the constructor:

<pre><code>GiveFeedback += new GiveFeedbackEventHandler(Drag.UpdateCursor);
</code></pre>

and in this method:

<pre><code> protected override void OnMouseMove(MouseEventArgs mea) {
 if (Drag.IsDragging(mea)) {
 Drag.StartDragging(this);
 DragDropEffects dde = DoDragDrop(Plan, DragDropEffects.Move | DragDropEffects.Copy);
 Drag.StopDragging();
 }
 }
</code></pre>

blocks|key|1201447|text|这可能是一种选择：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1201448|private+void+btntarget_MouseDown(object+sender,+MouseEventArgs+e)
++++{++++++++++++++++++++++++++++++++

++++++++Bitmap+bmp+=+new+Bitmap(btntarget.Width,+btntarget.Height);
++++++++btntarget.DrawToBitmap(bmp,+new+Rectangle(Point.Empty,+bmp.Size));
++++++++//optionally+define+a+transparent+color
++++++++bmp.MakeTransparent(Color.White);

++++++++Cursor+cur+=+new+Cursor(bmp.GetHicon());++++++++++++++++++++++++++++++++
++++++++Cursor.Current+=+cur;++++++++++++

++++}|code-block|syntax|javascript|1201449|光标的热点将在图像的中间创建|1201450|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

this could be an option:

<pre><code>private void btntarget_MouseDown(object sender, MouseEventArgs e)
 { 

 Bitmap bmp = new Bitmap(btntarget.Width, btntarget.Height);
 btntarget.DrawToBitmap(bmp, new Rectangle(Point.Empty, bmp.Size));
 //optionally define a transparent color
 bmp.MakeTransparent(Color.White);

 Cursor cur = new Cursor(bmp.GetHicon()); 
 Cursor.Current = cur; 

 }
</code></pre>

the cursor's hotspot will be created at the middle of the image

blocks|key|986990|text|基于之前的答案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|986991|首先定义方法MouseDown+(在我的例子中我使用了一个按钮，但也可以应用于其他控件)。|986992|++++++++private+void+btn_MouseDown(object+sender,+MouseEventArgs+e)
++++{
++++++++//Cast+the+sender+to+control+type+youre+using
++++++++Button+send+=+(Button)sender;
++++++++//Copy+the+control+in+a+bitmap
++++++++Bitmap+bmp+=+new+Bitmap(send.Width,+send.Height);
++++++++send.DrawToBitmap(bmp,+new+Rectangle(Point.Empty,+bmp.Size));++++++++++++
++++++++//In+a+variable+save+the+cursor+with+the+image+of+your+controler
++++++++this.BitMapCursor+=+new+Cursor(bmp.GetHicon());+++++++++++++
++++++++send.DoDragDrop(send.Text,+DragDropEffects.Move);
++++}|code-block|syntax|javascript|986993|我之所以选择发送者，是因为在我的应用中，buttón是实时生成的。|986994|现在定义方法GiveFeedBack(此方法在拖动操作期间发生)。|986995|++++private+void+btn_GiveFeedback(object+sender,+GiveFeedbackEventArgs+e)
++++{
++++++++//Deactivate+the+default+cursor
++++++++e.UseDefaultCursors+=+false;+++++++
++++++++//Use+the+cursor+created+from+the+bitmap
++++++++Cursor.Current+=+this.BitMapCursor;

++++}|986996|结束时，不要忘记暂停对方法的控制|986997|btn.Click+%2B=+new+EventHandler(ClickButton);
btn.MouseDown+%2B=+new+MouseEventHandler(btn_MouseDown);
btn.GiveFeedback+%2B=+new+GiveFeedbackEventHandler(btn_GiveFeedback);|986998|entityMap^0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|W|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|X|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|Y|8|@]|9|@]|A|$]]|$1|M|3|N|5|F|7|Z|8|@]|9|@]|A|$G|H]]|$1|O|3|P|5|6|7|10|8|@]|9|@]|A|$]]|$1|Q|3|R|5|F|7|11|8|@]|9|@]|A|$G|H]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

Based on a previous answer:

First define the method MouseDown (in my case i use a button, but is aplicable at other controls).

<pre><code> private void btn_MouseDown(object sender, MouseEventArgs e)
 {
 //Cast the sender to control type youre using
 Button send = (Button)sender;
 //Copy the control in a bitmap
 Bitmap bmp = new Bitmap(send.Width, send.Height);
 send.DrawToBitmap(bmp, new Rectangle(Point.Empty, bmp.Size)); 
 //In a variable save the cursor with the image of your controler
 this.BitMapCursor = new Cursor(bmp.GetHicon()); 
 send.DoDragDrop(send.Text, DragDropEffects.Move);
 }
</code></pre>

i am casting the sender because in my aplicattion the buttón is be generated in real time. 

Now define the method GiveFeedBack(this method occurs during a drag operation.)

<pre><code> private void btn_GiveFeedback(object sender, GiveFeedbackEventArgs e)
 {
 //Deactivate the default cursor
 e.UseDefaultCursors = false; 
 //Use the cursor created from the bitmap
 Cursor.Current = this.BitMapCursor;

 }
</code></pre>

To end dont forget suscribe the control to the methods

<pre><code>btn.Click += new EventHandler(ClickButton);
btn.MouseDown += new MouseEventHandler(btn_MouseDown);
btn.GiveFeedback += new GiveFeedbackEventHandler(btn_GiveFeedback);
</code></pre>

I'm building a desktop app in C# with Windows Forms. I have a custom Control, and I'd like to be able to drag and drop it within my application (not outside). Right now I'm implementing that with the usual DoDragDrop/OnDragOver/OnDragDrop methods. Is there any way to continuously paint the control as it gets dragged around--sort of what you see with JQuery's drag-and-drop? I want the actual control to stay in place, but I want to paint a copy of its appearance as the user drags it. Ideally the copy would even be semi-transparent, but that's more a "nice to have."

The only way I can think to do this is to put the paint code in the main form's OnPaint method, but that seems like an inelegant solution. Any other ideas? Are things any easier if the Control paints itself as just a Bitmap?

C# Drag-and-Drop: Show the dragged item while dragging

Windows

我正在使用Windows Forms在C#中构建一个桌面应用程序。我有一个自定义的控件，我希望能够将它拖放到我的应用程序中(而不是外部)。现在，我正在用通常的DoDragDrop/OnDragOver/OnDragDrop方法实现它。有没有办法在控件被拖来拖去时持续绘制它--就像您在JQuery的拖放中看到的那样？我希...

问C#拖放:在拖拽的同时显示拖拽的项目
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