Tip 80: Drawing Borders Around Controls

* VB-CODE (2)
Abstract
You can draw borders of any width around controls such as Text Boxes
to give the control a three-dimensional look. This article explains
how to add a border to a control.

Using a Pen and Brush to Draw Borders
Through functions included in the Windows® application programming
interface (API), you can draw borders around controls in your Visual
Basic® application. The CreatePen function can be used to draw lines
(solid, invisible, dotted) and the CreateSolidBrush function can be
used to fill areas of an object.

After you have created a pen and brush to use with the specific
object (such as a Text Box control) that you want to draw filled
lines around, you need to determine the coordinates of the bounding
rectangle around the target object. Next, you must intercept the
Windows WM_PAINT message. The WM_PAINT message triggers Visual
Basic's Paint event. The message is sent to a window when the window
needs to have its client area redrawn. The Message Blaster custom
control can be used to process the WM_PAINT message. For information
on the Message Blaster custom control, see the reference materials
listed at the end of this article. Once the Paint event has been
triggered, the control is redrawn with the desired borders around
its perimeter.

Example Program
The program below shows how to add a three-dimensional look to a Text
Box control. This program draws a filled line across the top and down
the right-hand border of the Text Box.

1. Create a new project in Visual Basic. Form1 is created by default.
2. Add a Text Box control to Form1. Text1 is created by default.
3. From Visual Basic's Tools menu, select Custom Controls and add the
  MSGBLAST.VBX to your Toolbox. Add a Message Blaster control to
  Form1. MsgBlaster1 is created by default.
4. Add the following Dim, Constant, and Declare statements to the
  General Declarations section of Form1 (note that each Private
  Declare statement must be typed as a single line of code):

Const PS_SOLID = &H0
Const WM_PAINT = &HF

Private Declare Function DeleteObject Lib "GDI" (ByVal hObject
 As Integer) As Integer
Private Declare Function SelectObject Lib "GDI" (ByVal hDC
 As Integer, ByVal hObject As Integer) As Integer
Private Declare Function Polygon Lib "GDI" (ByVal hDC
 As Integer, lpPoints As POINTAPI, ByVal nCount
 As Integer) As Integer
Private Declare Function CreateSolidBrush Lib "GDI" (ByVal crColor
 As Long) As Integer
Private Declare Function GetDC Lib "User" (ByVal hWnd
 As Integer) As Integer
Private Declare Function CreatePen Lib "GDI" (ByVal nPenStyle
 As Integer, ByVal nWidth As Integer, ByVal crColor
 As Long) As Integer

Dim TX As Integer
Dim TY As Integer
Dim DC_FRM As Integer
Dim PT1() As POINTAPI
Dim PT2() As POINTAPI

5. Add the following code to the Form_Load event for Form1:

Private Sub Form_Load()
  MsgBlaster1.hWndTarget = Form1.hWnd
  MsgBlaster1.MsgList(0) = WM_PAINT
  MsgBlaster1.MsgPassage(0) = -1
End Sub

6. Add the following code to the Form_Activate event for Form1:

Private Sub Form_Activate()
  TX = Screen.TwipsPerPixelX
  TY = Screen.TwipsPerPixelY
  DC_FRM = GetDC(Form1.hWnd)
  Get_Rect
End Sub

7. Add the following code to the MsgBlaster1_Message event (note that
  the Private statement must be typed as a single line of code):

Private Sub MsgBlaster1_Message(MsgVal As Integer, wParam
 As Integer, lParam As Long, ReturnVal As Long)
  Shadow
End Sub

8. Create a new procedure called Get_Rect. Add the following code to
  this procedure:

Sub Get_Rect()
  ReDim PT1(6) As POINTAPI
  ReDim PT2(6) As POINTAPI

  PT1(0).X = Text1.Left / TX
  PT1(0).Y = Text1.Top / TY
  PT1(1).X = (Text1.Left) / TX + 2
  PT1(1).Y = (Text1.Top) / TY - 2
  PT1(2).X = (Text1.Left + Text1.Width) / TX + 2
  PT1(2).Y = (Text1.Top) / TY - 2
  PT1(3).X = (Text1.Left + Text1.Width) / TX + 2
  PT1(3).Y = (Text1.Top + Text1.Height) / TY - 2
  PT1(4).X = (Text1.Left + Text1.Width) / TX
  PT1(4).Y = (Text1.Top + Text1.Height) / TY
  PT1(5).X = (Text1.Left + Text1.Width) / TX
  PT1(5).Y = (Text1.Top) / TY
End Sub

9. Create a new procedure called Shadow. Add the following code to
  this procedure:

Sub Shadow()
  hbr = CreateSolidBrush(RGB(125, 125, 125))
  hpen = CreatePen(PS_SOLID, 1, RGB(125, 125, 125))

  r = SelectObject(DC_FRM, hbr)
  r = SelectObject(DC_FRM, hpen)
  r = Polygon(DC_FRM, PT1(0), 6)
  r = SelectObject(DC_FRM, rbrush)
  r1 = DeleteObject(r)
  r = SelectObject(DC_FRM, rpen)
  r1 = DeleteObject(r)
End Sub

10. Add a new module to the project. Module.Bas is created by default.
11. Add the following POINTAPI structure to Module.Bas:

Type POINTAPI   '4 bytes
  X As Integer
  Y As Integer
End Type

Additional References
"Advanced Programming in Visual Basic 3.0 (Accessing the Windows
 API)." (Conferences and Seminars, Tech·Ed, March 1994, Visual
 Basic)
"Message Blaster: Processing Messages in Visual Basic." (Technical
 Articles, Visual Basic Articles)
"Tips and Tricks for Visual Basic." (Conferences and Seminars,
 Tech·Ed, March 1994, Visual Basic)
"Using MSGBLAST.VBX Control to Process Windows Messages from VB."
 (Knowledge Base and Bug Lists, Visual Basic for Windows KBase,
 Miscellaneous Related Information.)