Tip 69: Forcing a Picture Control to Use Only a Specific Font

May 1, 1995

Abstract

When developing an application in Visual Basic® that may be run on many different computer systems, you may want to ensure that a control such as a Picture Box is formatted correctly with regard to the size and type of font used. This article explains how you can use the Windows® application programming interface (API) SendMessage and GetStockObject functions to force a control to use a specific font when displaying text.

Using the GetStockObject Function to Select a Font

Many controls such as Picture Box and Text Box controls have a Font property. The Font property is usually set by the programmer at design time to a specific font. However, in some situations, you may want to force Windows® to use a different font at a specific time in your program for that control. In such cases, you can use the Windows application programming interface (API) SendMessage and GetStockObject functions to tell Windows that a control's Font property is to be set to a different font.

To change a control's Font property to another font, you use the GetStockObject function. The Declare statement for this function is as follows:

Declare Function GetStockObject Lib "GDI" (ByVal nIndex As Integer) As Integer

GetStockObject requires only one argument—an integer value containing the type of stock object you want to use. In our case, we want to use the ANSI_FIXED_FONT stock object, which has a value of 11. After you call the GetStockObject function, it returns an integer value. This value is set to NULL if the function was not successful, or to a handle that identifies the logical object itself.

In the example program below, we want to force the Picture Box control to use a fixed font instead of Bookman Old Style, which is set to a point size of 24, at design time. To set the font to a fixed font while the program is being executed, we issue the following statement:

X = SendMessage(Picture1.hWnd, WM_SETFONT, GetStockObject(ANSI_FIXED_FONT), 1)

After issuing this command, anytime we use the Print method to print text on the Picture Box control, the fixed font is used.

Example Program

The example program below displays a Picture Box control on Form1. The Print method is used to display the text "This is a test" in the Picture Box control. Note that the default Font property value is ignored and the ANSI fixed font is used when the text is displayed in the control.

1. Create a new project in Visual Basic. Form1 is created by default.
   
   
2. Add the following Constant and Declare statements to the General Declarations section of Form1 (note that each Declare statement should be typed as a single line of code):

   Declare Function SendMessage Lib "User" (ByVal hWnd As Integer, ByVal wMsg As 
      Integer, ByVal wParam As Integer, lParam As Any) As Long
   Declare Function GetStockObject Lib "GDI" (ByVal nIndex As Integer) As Integer
   Const ANSI_FIXED_FONT = 11
   Const WM_SETFONT = &H30
   

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

   Sub Form_Load()
       Dim X As Long
       X = SendMessage(Picture1.hWnd, WM_SETFONT, GetStockObject(ANSI_FIXED_FONT),
         1)
       Picture1.Print "This is a test"
       
   End Sub
   

4. Add a Picture Box control to Form1. Set its Font property to Bookman Old Style, point size: 24.

Additional References

Knowledge Base Q75857. "How to Print the ASCII Character Set in Visual Basic."