FIX: Out of Memory Error When Adding 35-50 Pen Controls

The information in this article applies to:

- Standard and Professional Editions of Microsoft Visual Basic

  programming system for Windows, versions 2.0 and 3.0

SYMPTOMS

You will receive an "Out of Memory" error message if you attempt to add more than approximately 36 HEdit or approximately 50 BEdit Pen Controls to an individual Form.

WORKAROUND

You can edit in only one control at a time, so use only one of each of the Pen Controls on top of multiple Labels or Picture Box Controls. This will display the result of the edit when you move the focus to another control.

The examples in the More Information section below will demonstrate how to do this for each of the Pen Controls.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This problem has been corrected in Visual Basic version 4.0.

MORE INFORMATION

Here are two examples showing how to work around this bug:

Step-by-Step Example One

The following example demonstrates how to use multiple Picture Boxes and one HEdit Control with the DelayRecog = True. This will allow the user to input signatures into a field which will then remain as written, no recognition is performed.

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

2. Add the following controls, and set the indicated properties:

      Control          Property     Value
      ----------------------------------------
      Picture Box      Name         PictureB
                       Index        0
                       AutoRedraw   True
   
      Picture Box      Name         PictureB
                       Index        1
                       AutoRedraw   True
   
      HEdit Control    Name         HEdit1
                       DelayRecog   True
                       Text         <blank>
   
      Command Button   Name         Command1
                       Caption      Clear
   
   

3. Add the following code to the General Declarations section of Form1:

      'Enter each of the following Declare statements on one, single line:
      Declare Function GetDC Lib "USER" (ByVal hWnd As Integer) As Integer
      Declare Function BitBlt Lib "GDI" (ByVal hDestDC As Integer,
         ByVal x As Integer, ByVal y As Integer, ByVal nWidth As Integer,
         ByVal nHeight As Integer, ByVal hSrsDC As Integer,
         ByVal xSrc As Integer, ByVal ySrc As Integer, ByVal dwRop) As Integer
   
         Const SRCCOPY &H00CC0020&  ' Will be used in the call to BitBlt
         Dim LastPos As Integer     ' Will be used to keep track of the
                                    ' last edited field.
         Dim InkArray(2) As String  ' This array will be used to store the
                                    ' InkDataString for each of the fields.
   
   

4. Add the following code to the appropriate Control's event procedures:

      Sub Command1_Click ()
         HEdit1.InkDataString = ""     ' Clear the field.
      End Sub
   
      Sub Form_Load ()
         Call PictureB_Click(0)    ' Position the HEdit control over the
      End Sub                      ' first field.
   
      Sub Picture1_Click (index As Integer)
         ' Copy the image in the HEdit control to the Picture Box
         destDC = GetDC(HEdit.hWnd)
         ' Enter the following three lines as one, single line:
         dummy% = BitBlt(PictureB(LastPos).HDC, 0, 0,
            PictureB(LastPos).ScaleWidth-2, PictureB(LastPos).ScaleHeight-2,
            destDC, 1, 1)
         InkArray(LastPos) = HEdit1.InkDataString
         ' Save the Ink data for this field.  It will be reassigned
         ' to the HEdit control the next time that field is selected
         ' and the HEdit control is positioned on top of it.
         LastPos = index        ' Update LastPos to the current field.
         HEdit1.Visible = False ' This prevent a flicker when the
                                ' control is moved.
         HEdit1.Top = PictureB(index).Top     ' Move the HEdit Control on
         HEdit1.Left = PictureB(index).Left   ' top of the selected Picture
         HEdit1.Width = PictureB(index).Width ' box field.
         HEdit1.Height = PictureB(index).Height
         HEdit1.InkDataString = InkArray(index) ' Reset the Ink in the
                                                ' Hedit Control to that
                                                ' stored for this field.
         HEdit1.Visible = True
      End Sub
   
   

Step-by-Step Example Two

The following example demonstrates how to use multiple Labels and one HEdit Control with DelayRecog = False. This works using a BEdit control as well. This allows the user to input hand-written characters into a field where those characters will then be recognized and converted into font characters.