Q153929: HOWTO: Use Color Dialog from COMDLG32.DLL in VB and Access

Article: Q153929
Product(s): Microsoft Visual Basic for Windows
Version(s): 4.0,5.0,6.0
Operating System(s): 
Keyword(s): kbGrpDSVB
Last Modified: 20-FEB-2002

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The information in this article applies to:

- Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Standard Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, version 4.0 
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SUMMARY
=======

Making use of the COMDLG32.DLL is a good reuse of resources under Windows
because Windows always has COMDLG32.DLL loaded. If you use the COMDLG32.OCX
control instead, your program must load the OCX into memory and you must also
distribute an additional 90K file to your customers. The OCX control provides an
easy-to-use interface to predefined dialog boxes, but is a more expensive hit on
performance and resources. To optimize performance and reduce resource usage,
you should minimize the use of controls in your applications and use the Win32
API calls directly. Below is a code sample of how to use the Choose Color dialog
box in the COMDLG32.DLL.

MORE INFORMATION
================

1a. Visual Basic: Start a new project. Form1 is created by default.

1b. Access: Open a database and create a new form.

1. Add a CommandButton (Command1) to the form.

2. Add the following code to the General Declarations section of the form:

     Option Explicit

     Private Type CHOOSECOLOR
       lStructSize As Long
       hwndOwner As Long
       hInstance As Long
       rgbResult As Long
       lpCustColors As String
       flags As Long
       lCustData As Long
       lpfnHook As Long
       lpTemplateName As String
     End Type

     Private Declare Function ChooseColorAPI Lib "comdlg32.dll" Alias _
       "ChooseColorA" (pChoosecolor As CHOOSECOLOR) As Long

     Dim CustomColors() As Byte

     Private Sub Command1_Click()
         Dim cc As CHOOSECOLOR
         Dim Custcolor(16) As Long
         Dim lReturn As Long
         cc.lStructSize = Len(cc)
         cc.hwndOwner = Me.hWnd
         cc.hInstance = 0
         cc.lpCustColors = StrConv(CustomColors, vbUnicode)
         cc.flags = 0
         lReturn = ChooseColorAPI(cc)
         If lReturn <> 0 Then
             Me.Caption = "RGB Value User Chose: " & Str$(cc.rgbResult)
             Me.BackColor = cc.rgbResult            ' Visual Basic only ****
             Me.Section(0).BackColor = cc.rgbResult ' Access only **********
             CustomColors = StrConv(cc.lpCustColors, vbFromUnicode)
         Else
             MsgBox "User chose the Cancel Button"
         End If
     End Sub

     Private Sub Form_Load()
         ReDim CustomColors(0 To 16 * 4 - 1) As Byte
         Dim i As Integer

         For i = LBound(CustomColors) To UBound(CustomColors)
             CustomColors(i) = 0
         Next i
     End Sub

4a. Visual Basic: Press the F5 key to run the project.

4b. Access: Use the View|Form menu to open the form and run it.

1. Click the CommandButton and the Color dialog box will be displayed. When you
  choose a color and press OK, the background color of the form will change to
  your selected color.

The constant CC_PREVENTFULLOPEN, with a decimal value of 4, can be used in the
flags element of the CHOOSECOLOR structure if you wish to prevent the Custom
Colors part of the Dialog from being displayed.

NOTE: In the Command1_Click routine above, the code to set the background color
of an Access form and a Visual Basic form is slightly different. Both commands
are included and commented. Only type the command that is appropriate for the
product you are using.


REFERENCES
==========

Microsoft Visual Basic Programmer's Guide, Chapter 11, P.325-332.

Win32 SDK.

Additional query words: Common kbVBp400 kbVBp500 kbVBp600 kbVBp kbdsd kbDSupport knintluk kbNoKeyWord

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Keywords          : kbGrpDSVB 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVB500 kbVB600 kbVB400Search kbVB400
Version           : :4.0,5.0,6.0
Issue type        : kbhowto

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