Rubberband in a PictureBox

[Pruned1212444]

This program was created in Microsoft Visual Basic 2010 Express to demonstrate how to draw a rubberband rectangle in a picture box.

After creating a Windows Forms Applications, resize Form1 to 500 x 500. Add a PictureBox control to Form1 and resize to fill the Form workspace. Change the following PictureBox1 Properties

Anchor - select Top, Bottom, Left, & Right
BackColor - White

You will use the Form1 event Load to enter the initial properties of the Pen. In this example, the Rubberband will be a dashed black line with a line width of 1.5.

Picturebox1 events used are Mouseown, MouseMove, MouseUp and Resize. When you press the mouse button on the Picturebox the starting position will be saved in Xstart and Ystart. Picturebox1.Refresh is used to clear any previous drawings.

As the mouse is moved across the Picturebox, the location will be updated and a new rectangle is drawn using the DrawRectangle subroutine. Depending on the direction the mouse is moving with respect to the starting point will determine the values used in the RBrectangle variable.

When the mouse button is released, the process is stopped by setting bRB as false. You can add code in this area to do something with the area that is rubberbanded.

If you resize the Form, the boundaries of the Picturebox are updated. In order to keep the rectangle visible along the right and bottom edges, you will need to reduce the values of PBWidth and PBHeight by 1.

1. Dim
   
   Xstart As
   
   Integer
   
2. Dim
   
   Ystart As
   
   Integer
   
3. Dim
   
   PBWidth As
   
   Integer
   
4. Dim
   
   PBHeight As
   
   Integer
   
5. Dim
   
   bRB As
   
   Boolean
   
6. Dim
   
   RBPen As
   
   Pen
   
7. Dim
   
   RBRectangle As
   
   Rectangle
   
8. 
   
9. Private
   
   Sub
   
   Form1_Load(
   
   sender As
   
   Object
   
   , e As
   
   System.
   
   EventArgs
   
   )
   
   Handles
   
   Me
   
   .
   
   Load
   
10. RBPen =
    
    New
    
    Pen(
    
    Color.
    
    Black
    
    , 1.5
    
    )
    
    'Color, Width
    
11. RBPen.
    
    DashStyle
    
    =
    
    Drawing2D.
    
    DashStyle
    
    .
    
    Dash
    
12. End
    
    Sub
    
13. 
    
14. Private
    
    Sub
    
    PictureBox1_MouseDown(
    
    sender As
    
    Object
    
    , e As
    
    System.
    
    Windows
    
    .
    
    Forms
    
    .
    
    MouseEventArgs
    
    )
    
    Handles
    
    PictureBox1.
    
    MouseDown
    
15. PictureBox1.
    
    Refresh
    
    (
    
    )
    
    'erases previous rectangle
    
16. Xstart =
    
    e.
    
    X
    
17. Ystart =
    
    e.
    
    Y
    
18. bRB =
    
    True
    
19. End
    
    Sub
    
20. 
    
21. Private
    
    Sub
    
    PictureBox1_MouseMove(
    
    sender As
    
    Object
    
    , e As
    
    System.
    
    Windows
    
    .
    
    Forms
    
    .
    
    MouseEventArgs
    
    )
    
    Handles
    
    PictureBox1.
    
    MouseMove
    
22. If
    
    bRB Then
    
23. PictureBox1.
    
    Refresh
    
    (
    
    )
    
    'erases previous rectangle
    
24. 
    
25. Select
    
    Case
    
    e.
    
    X
    
26. Case
    
    Is
    
    <
    
    0
    
27. RBRectangle.
    
    X
    
    =
    
    0
    
28. RBRectangle.
    
    Width
    
    =
    
    Xstart
    
29. Case
    
    0
    
    To
    
    Xstart
    
30. RBRectangle.
    
    X
    
    =
    
    e.
    
    X
    
31. RBRectangle.
    
    Width
    
    =
    
    Xstart -
    
    e.
    
    X
    
32. Case
    
    Xstart To
    
    PBWidth
    
33. RBRectangle.
    
    X
    
    =
    
    Xstart
    
34. RBRectangle.
    
    Width
    
    =
    
    e.
    
    X
    
    -
    
    Xstart
    
35. Case
    
    Is
    
    >
    
    PBWidth
    
36. RBRectangle.
    
    X
    
    =
    
    Xstart
    
37. RBRectangle.
    
    Width
    
    =
    
    PBWidth -
    
    Xstart
    
38. End
    
    Select
    
39. 
    
40. Select
    
    Case
    
    e.
    
    Y
    
41. Case
    
    Is
    
    <
    
    0
    
42. RBRectangle.
    
    Y
    
    =
    
    0
    
43. RBRectangle.
    
    Height
    
    =
    
    Ystart
    
44. Case
    
    0
    
    To
    
    Ystart
    
45. RBRectangle.
    
    Y
    
    =
    
    e.
    
    Y
    
46. RBRectangle.
    
    Height
    
    =
    
    Ystart -
    
    e.
    
    Y
    
47. Case
    
    Ystart To
    
    PBHeight
    
48. RBRectangle.
    
    Y
    
    =
    
    Ystart
    
49. RBRectangle.
    
    Height
    
    =
    
    e.
    
    Y
    
    -
    
    Ystart
    
50. Case
    
    Is
    
    >
    
    PBHeight
    
51. RBRectangle.
    
    Y
    
    =
    
    Ystart
    
52. RBRectangle.
    
    Height
    
    =
    
    PBHeight -
    
    Ystart
    
53. End
    
    Select
    
54. 
    
55. PictureBox1.
    
    CreateGraphics
    
    .
    
    DrawRectangle
    
    (
    
    RBPen, RBRectangle)
    
56. End
    
    If
    
57. End
    
    Sub
    
58. 
    
59. Private
    
    Sub
    
    PictureBox1_MouseUp(
    
    sender As
    
    Object
    
    , e As
    
    System.
    
    Windows
    
    .
    
    Forms
    
    .
    
    MouseEventArgs
    
    )
    
    Handles
    
    PictureBox1.
    
    MouseUp
    
60. If
    
    bRB Then
    
61. bRB =
    
    False
    
62. 'Add code here
    
63. End
    
    If
    
64. End
    
    Sub
    
65. 
    
66. Private
    
    Sub
    
    PictureBox1_Resize(
    
    sender As
    
    Object
    
    , e As
    
    System.
    
    EventArgs
    
    )
    
    Handles
    
    PictureBox1.
    
    Resize
    
67. PBWidth =
    
    PictureBox1.
    
    Width
    
    -
    
    1
    
    'Right edge
    
68. PBHeight =
    
    PictureBox1.
    
    Height
    
    -
    
    1
    
    'Bottom edge
    
69. End
    
    Sub
    

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