.net中picturebox中圖片的拖動
首先在form窗體上放一個picturebox，并指定一個圖片顯示

定義一系列變量處理圖片拖動
 '處理圖片拖動
        private m_leftx as integer
        private m_lefty as integer
        dim m_mouseposx as integer
        dim m_mouseposy as integer
        dim m_driftx as integer
        dim m_drifty as integer
并給賦初值，可以在form初始化時做
  me.m_leftx = me.picturebox1.location.x
        me.m_lefty = me.picturebox1.location.y

定義處理鼠標按下的事件

 '當鼠標按下時，將鼠標變成手形，并且記錄下當前鼠標的位置
  private sub picturebox1_mousedown(byval sender as object, byval e as system.windows.forms.mouseeventargs) handles picturebox1.mousedown

            me.cursor = system.windows.forms.cursors.hand
            m_mouseposx = e.x
            m_mouseposy = e.y

        end sub
定義處理鼠標抬起的事件
 '處理鼠標按鍵抬起的事件，根據鼠標按下時保存的鼠標位置，和當前鼠標的位置，計算鼠標移動偏移量，借此調用移動圖片的函數，移動圖片
        private sub picturebox1_mouseup(byval sender as object, byval e as system.windows.forms.mouseeventargs) handles picturebox1.mouseup
          
            m_driftx = m_mouseposx - e.x
            m_drifty = m_mouseposy - e.y
         
            m_leftx = m_leftx - m_driftx
            m_lefty = m_lefty - m_drifty
          
            picturemove(sender, e)
            me.cursor = system.windows.forms.cursors.arrow

        end sub

 '根據偏移量計算出的圖片位置，重畫圖片
        private sub picturemove(byval sender as object, byval e as system.windows.forms.mouseeventargs)
            dim mybit as new system.drawing.bitmap(picturebox1.image)

            dim mypicgrh as system.drawing.graphics = me.picturebox1.creategraphics
            mypicgrh.clear(me.picturebox1.backcolor)
           
            mypicgrh.drawimageunscaled(mybit, m_leftx - 152, m_lefty)

            mybit.dispose()
            mypicgrh.dispose()

        end sub