ACC2000: How to Get the Right and Down Measurements of a Form

The information in this article applies to:

Microsoft Access 2000
Microsoft Visual Basic for Applications

Advanced: Requires expert coding, interoperability, and multiuser skills.

This article applies to a Microsoft Access database (.mdb) and a Microsoft Access project (.adp).

MORE INFORMATION

In Microsoft Access, you can use the WindowWidth and WindowHeight form properties to determine the current width and height of the window that a form is contained in. However, there are no properties to determine the window's right and down measurements (these measurements are commonly used in the MoveSize macro action to position a form window).

The right and down measurements, along with the width and height, are useful if you want to position a form side-by-side with another form. The following examples show you how to create and use the GetFormDimensions Sub procedure to get these measurements and to use them to position a form to the right of, and then below, another form by using the MoveSize macro action.

How to Create the Sub Procedure

Open the sample database Northwind.mdb.
Create a module and type the following line in the Declarations section:

Option Explicit

Type RECT_Type

   left As Long

   top As Long

   right As Long

   bottom As Long

End Type

Declare Function apiGetWindowRect Lib "user32" Alias _

   "GetWindowRect" (ByVal hWnd As Long, lpRect As RECT_Type) As Long

Declare Function apiGetDC Lib "user32" Alias "GetDC" _

   (ByVal hWnd As Long) As Long

Declare Function apiReleaseDC Lib "user32" Alias "ReleaseDC" (ByVal _

   hWnd As Long, ByVal hDC As Long) As Long

Declare Function apiGetDeviceCaps Lib "gdi32" Alias "GetDeviceCaps" _

   (ByVal hDC As Long, ByVal nIndex As Long) As Long

Declare Function apiGetActiveWindow Lib "user32" Alias _

   "GetActiveWindow" () As Long

Declare Function apiGetParent Lib "user32" Alias "GetParent" (ByVal _

   hWnd As Long) As Long

Declare Function apiGetClassName Lib "user32" Alias "GetClassNameA" _

   (ByVal hWnd As Long, ByVal lpClassName As String, ByVal _

   nMaxCount As Long) As Long

Global Const TWIPSPERINCH = 1440

Type the following procedure:

Sub GetFormDimensions(F As Form, FLeft As Long, FTop As Long, _

   FWidth As Long, FHeight As Long)

   '*************************************************************

   ' PURPOSE: Returns the left, top, width, and height

   '          measurements of a form window in tdwips.

   ' ARGUMENTS:

   '    F: The form object whose measurements are to be determined.

   '    FLeft, FTop, FWidth, FHeight: Measurement variables

   '    that will return the dimensions of form F "by reference."

   ' NOTE: The FWidth and FHeight values will be equivalent to

   '    those provided by the form WindowWidth and WindowHeight

   '    properties.

   '*************************************************************

   Dim FormRect As RECT_Type

   Dim MDIClient As RECT_Type

   Dim MDIClientLeft As Long

   Dim MDIClientTop  As Long

   ' Get the screen coordinates and window size of the form.

   ' The screen coordinates are returned in pixels measured

   ' from the upper-left corner of the screen.

   apiGetWindowRect F.hWnd, FormRect

   FLeft = FormRect.left

   FTop = FormRect.top

   FWidth = FormRect.right - FormRect.left

   FHeight = FormRect.bottom - FormRect.top

   ' Convert the measurements from pixels to twips.

   ConvertPIXELSToTWIPS FLeft, FTop

   ConvertPIXELSToTWIPS FWidth, FHeight

   ' If the form is not a pop-up form, adjust the screen

   ' coordinates to measure from the top of the Microsoft

   ' Access MDIClient window. Position 0,0 for a pop-up form

   ' is the upper-left corner of the screen, whereas position

   ' 0,0 for a normal window is the upper-left corner of the

   ' Microsoft Access client window below the menu bar.

   If GetWindowClass(F.hWnd) <> "OFormPopup" Then

      ' Get the screen coordinates and window size of the

      ' MDIClient window.

      apiGetWindowRect apiGetParent(F.hWnd), MDIClient

      MDIClientLeft = MDIClient.left

      MDIClientTop = MDIClient.top

      ConvertPIXELSToTWIPS MDIClientLeft, MDIClientTop

      ' Adjust the form dimensions from the MDIClient

      ' measurements.

      FLeft = FLeft - MDIClientLeft

      FTop = FTop - MDIClientTop

   End If

End Sub

Sub ConvertPIXELSToTWIPS(X As Long, Y As Long)

   '*************************************************************

   ' PURPOSE: Converts the two pixel measurements passed as

   '          arguments to twips.

   ' ARGUMENTS:

   '    X, Y: Measurement variables in pixels. These will be

   '          converted to twips and returned through the same

   '          variables "by reference."

   '*************************************************************

   Dim hDC As Long, hWnd As Long, RetVal As Long

   Dim XPIXELSPERINCH, YPIXELSPERINCH

   Const LOGPIXELSX = 88

   Const LOGPIXELSY = 90

   ' Retrieve the current number of pixels per inch, which is

   ' resolution-dependent.

   hDC = apiGetDC(0)

   XPIXELSPERINCH = apiGetDeviceCaps(hDC, LOGPIXELSX)

   YPIXELSPERINCH = apiGetDeviceCaps(hDC, LOGPIXELSY)

   RetVal = apiReleaseDC(0, hDC)

   ' Compute and return the measurements in twips.

   X = (X / XPIXELSPERINCH) * TWIPSPERINCH

   Y = (Y / YPIXELSPERINCH) * TWIPSPERINCH

End Sub

Function GetWindowClass(hWnd As Long) As String

   '*************************************************************

   ' PURPOSE: Retrieve the class of the passed window handle.

   ' ARGUMENTS:

   '    hWnd: The window handle whose class is to be retrieved.

   ' RETURN:

   '    The window class name.

   '*************************************************************

   Dim Buff As String

   Dim BuffSize As Integer

   Buff = String$(255, " ")

   BuffSize = apiGetClassName(hWnd, Buff, 255)

   GetWindowClass = left$(Buff, BuffSize)

End Function

How to Use the GetFormDimensions Sub Procedure

Open the sample database Northwind.mdb.
Add the following Sub procedure to the module that you created in step 2 of the previous section:

Sub MoveEmployeesAround()

   Dim frmCust As Form

   Dim frmEmp As Form

   Dim frmCustLeft As Long

   Dim frmCustTop As Long

   Dim frmCustWidth As Long

   Dim frmCustHeight  As Long

   Dim frmEmpLeft As Long

   Dim frmEmpTop As Long

   Dim frmEmpWidth As Long

   Dim frmEmpHeight  As Long

   Set frmCust = Forms!Customers

   Set frmEmp = Forms!Employees

   GetFormDimensions frmCust, frmCustLeft, frmCustTop, _

   frmCustWidth, frmCustHeight

   GetFormDimensions frmEmp, frmEmpLeft, frmEmpTop, _

   frmEmpWidth, frmEmpHeight

   frmEmp.SetFocus

   MsgBox "Move Employees to the right of Customers!"

   DoCmd.MoveSize frmCustLeft + frmCustWidth, frmCustTop

   MsgBox "Move Employees below Customers!"

   DoCmd.MoveSize frmCustLeft, frmCustTop + frmCustHeight

End Sub

Open the Customers and Employees forms in Form view.
Open the Immediate window by pressing CTRL+G. Type the following line, and then press ENTER:

MoveEmployeesAround

In the message box that appears, click OK. The Employees form will be positioned immediately to the right of the Customers form, and then another message box will appear.
In the second message box, click OK. The Employees form will be positioned immediately below the Customers form.

NOTE: Depending on the position and size of the Customers form, the Employees form may be positioned so that you cannot see it.

REFERENCES

For more information about the WindowHeight and WindowWidth properties, click Microsoft Access Help on the Help menu, type "WindowHeight" or "WindowWidth" in the Office Assistant or the Answer Wizard, and then click Search to view the topic.