讲述VB.NET实现拖动图片

1. 环境：windows7 ,vb2010
4. Public Class Form1
5. Private m_MouseIsDown As Boolean
7. Private Sub Form1_Load(ByVal senderAs System.Object,ByVal e As System.EventArgs)Handles MyBase.Load
8. PictureBox2.AllowDrop = True
9. PictureBox1.AllowDrop = True
10. End Sub
13. Private Sub PictureBox1_MouseDown(ByVal senderAs Object,ByVal e As System.Windows.Forms.MouseEventArgs)Handles PictureBox1.MouseDown
14. If Not PictureBox1.ImageIs NothingThen ' Set a flag to show that the mouse is down.
15. m_MouseIsDown = True
16. End If
18. End Sub
20. Private Sub PictureBox1_MouseMove(ByVal senderAs Object,ByVal e As System.Windows.Forms.MouseEventArgs)Handles PictureBox1.MouseMove
21. If m_MouseIsDown Then ' Initiate dragging and allow either copy or move.
22. PictureBox1.DoDragDrop(PictureBox1.Image, DragDropEffects.Copy Or DragDropEffects.Move)
23. End If
24. m_MouseIsDown = False
25. End Sub
27. Private Sub PictureBox2_DragDrop(ByVal senderAs Object,ByVal e As System.Windows.Forms.DragEventArgs)Handles PictureBox2.DragDrop
28. ' Assign the image to the PictureBox.
29. PictureBox2.Image = e.Data.GetData(DataFormats.Bitmap)
30. ' If the CTRL key is not pressed, delete the source picture.
31. If Not e.KeyState = 8Then
32. PictureBox1.Image = Nothing
33. End If
34. End Sub
36. Private Sub PictureBox2_DragEnter(ByVal senderAs Object,ByVal e As System.Windows.Forms.DragEventArgs)Handles PictureBox2.DragEnter
37. If e.Data.GetDataPresent(DataFormats.Bitmap)Then ' Check for the CTRL key.
38. If e.KeyState = 9 Then
39. e.Effect = DragDropEffects.Copy
40. Else
41. e.Effect = DragDropEffects.Move
42. End If
43. Else
44. e.Effect = DragDropEffects.None
45. End If
46. End Sub
47. End Class