c# - Usercontrol drag & drop on Panel -

i'm making graphical editor, experiencing problems drag & drop on panel. ellipse doesn't take exact position drop it, , think it's placed in usercontrol of size 150;150. here's link of short movie illustrate mean: http://gyazo.com/abf5484a31e2d1ce8ebccc49bee9fdb6 in first part can see ellipse goes wrong position , in end of movie when draw line seems ellipse has block around it. how can solve issues?

form1.cs

public partial class form1 : form {     bool draw = false;     int x, y, xe, ye;      public form1()     {         initializecomponent();          menucomboboxshape.combobox.datasource = enum.getvalues(typeof(item));     }      public enum item     {         pencil,         rectangle,          ellipse,     }       private void panel_mousedown(object sender, mouseeventargs e)     {         draw = true;         x = e.x;         y = e.y;     }      private void panel_mouseup(object sender, mouseeventargs e)     {         draw = false;         xe = e.x;         ye = e.y;          item item;          enum.tryparse<item>(menucomboboxshape.combobox.selectedvalue.tostring(), out item);          switch (item)         {              case item.pencil:                 using (graphics g = panel.creategraphics())                     using (var pen = new pen(system.drawing.color.black))     //create pen used draw line (using statement makes sure pen disposed)                     {                         g.drawline(pen,new point(x, y), new point(xe, ye));                     }                 break;             case item.rectangle:                 rectangleshape recshape = new rectangleshape(x, y, xe - x, ye - y);                 panel.controls.add(recshape);                 panel.invalidate();                 break;             case item.ellipse:                 ellipseshapetest test = new ellipseshapetest(x, y, xe - x, ye - y);                 panel.controls.add(test);                 panel.invalidate();                 break;             default:                 break;         }     } } 

ellipseshapetest.cs

class ellipseshapetest : usercontrol {     private int x;     private int y;     private int width;     private int height;      public ellipseshapetest(int x, int y, int width, int height)     {         sety(y);         setx(x);         setwidth(width);         setheight(height);     }      public int getx() { return x;}     public int gety() { return y; }     public int getwidth() { return width; }     public int getheight() { return height; }     public void setx(int newx) { x = newx; }     public void sety(int newy) { y = newy; }     public void setwidth(int newwidth) { width = newwidth; }     public void setheight(int newheight) { height = newheight; }       protected override void onpaint(painteventargs e)     {         base.onpaint(e);         // call methods of system.drawing.graphics object.          // draw aqua rectangle in rectangle represented control.         e.graphics.drawellipse(pens.aqua,x,y,width,height);     }      protected override void onmousemove(mouseeventargs e)     {          // make cursor hand cursor when mouse moves           // on button.         cursor = cursors.hand;          // call mybase.onmousemove activate delegate.          base.onmousemove(e);          if (e.button == mousebuttons.left)         {             this.location = new point(e.x, e.y);             invalidate();         }      } 

here label subclass draggable. same code should work control, including usercontrol.

 public draglabel()  {      //..      mousedown += draglabel_mousedown;      mousemove += draglabel_mousemove;  }   point mdown { get; set; }   void draglabel_mousedown(object sender, mouseeventargs e)  {       mdown = e.location;  }   void draglabel_mousemove(object sender, mouseeventargs e)  {       if (e.button == mousebuttons.left)       {            location = new point(e.x + left - mdown.x, e.y + top - mdown.y);       }  } 

if application needs make several classes draggable, put fuctionality in dragcontroller class , register controls need there..

as second problem: in example see one control. in simple case should make uc's backcolor = color.transparent. once want add more such shapes hit wall and, i'm afraid, have give up on such design. see here discussion of problems , suggested solution..!

btw: using control move around active shape fine, other shapes have drawn onto background. (this makes more sense after have understood last paragraph ;-)