HOWTO: Add a Custom Font Property to a User Control

• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, versions 5.0, 6.0

SUMMARY

When you create a user control, you can add a custom property page that allows the user to set some or all of the properties you have created. This article describes a sample that demonstrates how to create a custom font property so that you can filter which fonts the user can select. It uses a custom property page from which you call the Font common dialog box so that it allows your users to select only from fixed pitch fonts.

MORE INFORMATION

You can create the properties you want and then you can either set them directly from the Property Page dialog box, or you can load a form or call the CommonDialog from the property page to set them. In steps 1 through 12 of the following example, you can create a version that requires going through one additional screen, the property page, but otherwise works substantially like the built-in Font property of the intrinsic controls. The instructions beginning with step 13 add code that hides the property page so that the effect is more like the built-in Font property.

Step-by-Step Procedures

1. Create a new Standard EXE project. Form1 is created by default.



2. From the Project menu, add a new UserControl Project. UserControl1 is created by default.



3. Add a TextBox and a Label to UserControl1.



4. Paste the following code into the UserControl code window:




      Option Explicit
      Private UseFont As String
      Private UseFontSize As Long

      Public Property Let MyFont(NewFont As String)
         Dim Ctrl As Control
         UseFont = NewFont
         PropertyChanged "MyFont"
         On Error Resume Next   ' For Controls without a Font property
         For Each Ctrl In Controls
            Ctrl.Font.Name = NewFont
         Next
      End Property

      Public Property Get MyFont() As String
         MyFont = UseFont
      End Property

      Public Property Get MyFontSize() As Long
         MyFontSize = UseFontSize
      End Property

      Private Property Let MyFontSize(NewValue As Long)
         Dim Ctrl As Control
         UseFontSize = NewValue
         PropertyChanged "MyFontSize"
         On Error Resume Next   ' For Controls without a Font property
         For Each Ctrl In Controls
            Ctrl.Font.Size = NewValue
         Next
      End Property
 

5. From the Project menu, add a new Property Page.



6. From the Project menu, click Components, click Microsoft Common Dialog Control, and click OK.



7. Add a CommonDialog, a CommandButton, and two TextBoxes (named txtMyFont and txtMyFontSize) to the Property Page.



8. Add the following code to the PropertyPage1 code window:




      Option Explicit

      Private Sub Command1_Click()
         CommonDialog1.Flags = cdlCFBoth Or cdlCFFixedPitchOnly
         CommonDialog1.FontName = SelectedControls(0).MyFont
         CommonDialog1.FontSize = SelectedControls(0).MyFontSize
         CommonDialog1.ShowFont
         txtMyFont.Text = CommonDialog1.FontName
         txtMyFontSize.Text = CommonDialog1.FontSize
      End Sub

      Private Sub txtMyFont_Change()
         Changed = True
      End Sub

      Private Sub txtMyFontSize_Change()
         Changed = True
      End Sub

      Private Sub PropertyPage_ApplyChanges()
         SelectedControls(0).MyFont = txtMyFont.Text
         SelectedControls(0).MyFontSize = txtMyFontSize.Text
      End Sub

      Private Sub PropertyPage_SelectionChanged()
         If SelectedControls(0).MyFont = "" Then
             txtMyFont.Text = "Courier"     ' Default
         Else
             txtMyFont.Text = SelectedControls(0).MyFont
         End If
         If SelectedControls(0).MyFontSize > 0 Then
             txtMyFontSize.Text = SelectedControls(0).MyFontSize
         Else
             txtMyFontSize.Text = 8     ' Default
         End If
      End Sub
 

9. Select the UserControl and click the PropertyPages property. Click the ellipsis button ("..."), select PropertyPage1, and click OK. This associates the Property Page you created with UserControl1.



10. Click the UserControl to make sure it is selected. From the Tools menu, click Procedure Attributes and select MyFont from the Name drop-down list. Click Advanced and select PropertyPage1 from the list under Use this Page in Property Browser:. This makes an ellipsis button ("...") appear when the user selects the MyFont property.



11. Close all design windows except for Form1. Add the UserControl to Form1.



12. When the UserControl has the focus, you will see a MyFont property in the Properties Window. Click MyFont to get the ellipsis button. Click the ellipsis button to go to the property page. From here the CommandButton brings up the filtered Font common dialog where you can choose your font. If you click OK or Apply, you set these properties. To demonstrate that this works, it also applies these settings to the TextBox and Label. You can also get to this dialog box by right-clicking on the UserControl and clicking Properties, or through the (Custom) property in the Properties Window.

1. Using the previous example, add a timer to the property page and add the following code to the top of the timer code window, just under Option Explicit:




      Private Declare Function GetParent Lib "user32" _
        (ByVal hwnd As Long) As Long

      Private Declare Function SetWindowPos Lib "user32" _
        (ByVal hwnd As Long, ByVal hWndInsertAfter As Long, _
        ByVal x As Long, ByVal y As Long, ByVal cx As Long, _
        ByVal cy As Long, ByVal wFlags As Long) As Long

      Private Declare Function PostMessage Lib "user32" Alias _
        "PostMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, _
        ByVal wParam As Long, ByVal lParam As Long) As Long

      Private Const HWND_TOP = 0
      Private Const SWP_NOSIZE = &H1
      Private Const SWP_HIDEWINDOW = &H80
      Private Const WM_CLOSE = &H10

      Dim hwndPP As Long

      Private Sub PropertyPage_Paint()
         Dim lresult As Long
         lresult = GetParent(PropertyPage.hwnd)   ' Work back to the
         hwndPP = GetParent(lresult)              ' dialog window.
         lresult = SetWindowPos(hwndPP, HWND_TOP, 200&, 200&, &O0, &O0, _
            SWP_HIDEWINDOW Or SWP_NOSIZE)
      End Sub

      Private Sub Timer1_Timer()
         Dim lRet As Long
         Timer1.Enabled = False     ' You will not need the Timer again.
         Command1.Value = True      ' Click the CommandButton.
         PropertyPage_ApplyChanges  ' Apply the new settings.
         lRet = PostMessage(hwndPP, WM_CLOSE, 0, 0) ' Close the dialog box.
      End Sub
 

2. Select the timer and set the Interval property to 1, then close all design windows.



3. Open the design window for Form1 and click the UserControl to give it focus. A MyFont property appears in the Properties window. Click on the MyFont property. An ellipsis button appears. If you click it, a filtered Font common dialog box appears (you never see the actual property page). This is fairly smooth, but there is a brief flicker as the dialog box opens and closes.

REFERENCES

Visual Basic Help, version 6.0; search on: ProperyPage Object

© Microsoft Corporation 1999, All Rights Reserved.
Contributions by Chris E. Jolley, Microsoft Corporation

Additional query words:

Keywords : kbAPI kbCtrlCreate kbPropSheet kbGrpUser kbVBp500 kbVBp600
Version : WINDOWS:5.0,6.0
Platform : WINDOWS
Issue type : kbhowto