INFO: VB 6.0 Readme Part 3: Control Issues

MORE INFORMATION

Lightweight Controls Must Be Borderless

When creating a lightweight User control by setting the Windowless property to True, the BorderStyle property is invalidated. By definition a lightweight control has no border.

If you first set the BorderStyle property to anything other than 0 - None and subsequently change the Windowless property to True, you will receive an error message "Windowless UserControls only support BorderStyle = None". Run Time Error 711: Compiled .Exe Doesn't Contain Information About Unreferenced Control Causing Controls.Add to Fail

Problem:

1. Create a new Standard EXE. Form1 is created by default.
2. Add a user control to the project.
3. Add the following code:
   

         Dim WithEvents x as VBControlExtender
   
         Private Sub Form_Load ()
             Set x = Controls.Add ("Project1.Usercontrol1", "XX")
             x.Visible = True
         End Sub
   
   						

4. On the File menu, click Make Project1.exe (Don't run the project.)
5. Run the EXE.
   
   Result: You get an error (711) stating that Project1.Usercontrol1 is an invalid ProgID since no info about it can be found in the exe.
   
   Solution: Before compiling the project, under the Project menu, click Project1 Properties. On the Make tab, clear the "Remove information about unused ActiveX controls" check box.

Remarks

By default, ActiveX controls that are referenced but not placed on any type of form at design time are not available for Controls.Add at runtime or in an executable.

Hierarchical FlexGrid Control: ColWordWrapOption, ColWordWrapOptionBand,

ColWordWrapOptionFixed, ColWordWrapOptionHeader Properties

The following properties are part of the Hierarchical FlexGrid control's feature set but are not documented in the control's help:

ColWordWrapOption, ColWordWrapOptionBand, ColWordWrapOptionFixed, ColWordWrapOptionHeader. Descriptions and syntaxes for these properties are found below. Settings for all properties are the same, and can be found at the bottom of the topic:

ColWordWrapOption Property
Returns or sets a value that specifies how text is wrapped in a specified column.
Syntax

object.ColWordWrapOption (Index) = integer
				

The ColWordWrapOption property syntax has these parts:

   Part                  Description
   ----------------------------------------------------
   object         An object expression that evaluates to a Hierarchical
                  FlexGrid control.

   Index          Long. The number of the column to get or set word wrap
                  on. The value must be in the range of -1 to Cols - 1.
                  Setting this value to -1 selects all columns.

   integer        A numeric expression that determines how words will wrap,
                  as shown in settings.
				

ColWordWrapOptionBand Property
Returns or sets a value that specifies how text is wrapped in a specified band.

Syntax

object.ColWordWrapOptionBand (BandNumber, BandColIndex) = integer
				

The ColWordWrapOption property syntax has these parts:

   Part                  Description
   ----------------------------------------------------
   object         An object expression that evaluates to a Hierarchical
                  FlexGrid control.

   BandNumber     Long. The number of the band to get or set word wrap on.
                  The value must be in the range of 0 to Bands - 1.

   BandColIndex   Long. The number of the column to get or set word wrap
                  on. This optional parameter defaults to -1, indicating
                  all columns in the band. Valid values are -1 to Cols -1.

   integer        A numeric expression that determines how words will wrap,
                  as shown in settings.
				

ColWordWrapOptionBand Property
Returns or sets a value that specifies how text is wrapped in a specified band.

Syntax

object.ColWordWrapOptionBand (BandNumber, BandColIndex) = integer
				

The ColWordWrapOption property syntax has these parts:

   Part              Description
   ---------------------------------------------------------------
   object         An object expression that evaluates to a
                  Hierarchical FlexGrid control.

   BandNumber     Long. The number of the band to get or set
                  word wrap on. The value must be in the range
                  of 0 to Bands - 1.

   BandColIndex   Long. The number of the column to get or set
                  word wrap on. This optional parameter
                  defaults to -1, indicating all columns in the
                  band. Valid values are -1 to Cols -1.

   integer        A numeric expression that determines how
                  words will wrap, as shown in settings.
				

ColWordWrapOptionFixed Property
Returns or sets a value that specifies how text is wrapped in a specified fixed column.

Syntax

object.ColWordWrapOptionFixed(index) = integer
				

The ColWordWrapOptionFixed property syntax has these parts:

   Part                  Description
   ----------------------------------------------------
   object         An object expression that evaluates to a Hierarchical
                  FlexGrid control.

   index          Long. The number of the column to get/set word wrap on.
                  This optional parameter defaults to -1. Valid values are
                  -1 to Cols -1.

   Integer        A numeric expression that determines how words will wrap,
                  as shown in settings.
				

ColWordWrapOptionFixed Property
Returns or sets a value that specifies how text is wrapped in a specified fixed column.

Syntax

object.ColWordWrapOptionFixed(index) = integer
				

The ColWordWrapOptionFixed property syntax has these parts:

   Part              Description
   ------------------------------------------------------------------
   object         An object expression that evaluates to a
                  Hierarchical FlexGrid control.

   index          Long. The number of the column to get/set
                  word wrap on. This optional parameter
                  defaults to -1. Valid values are -1 to Cols
                  -1.

   integer        A numeric expression that determines how
                  words will wrap, as shown in settings.
				

ColWordWrapOptionHeader Property
Returns or sets a value that specifies how text is wrapped in column headers.

Syntax

object.ColWordWrapOptionHeader(BandNumber, BandColIndex) = integer
				

The ColWordWrapOptionHeader property syntax has these parts:

   Part              Description
   --------------------------------------------------------------------
   object          An object expression that evaluates to a
                   Hierarchical FlexGrid control.

   BandNumber      Long. The number of the band to get/set word
                   wrap on. The value must be in the range of 0
                   to Bands - 1.

   BandColIndex    Long. The number of the column to get/set
                   word wrap on. This optional parameter
                   defaults to -1 indicating all column headers
                   in the band. Valid values are -1 to Cols -1.

   integer         A numeric expression that determines how
                   words will wrap, as shown in settings.
				

Settings
The settings for integer are:

   Constant             Value    Description
   ------------------------------------------------------------
   flexSingleLine       0       (Default) Displays text on a
                                single line only.

   flexWordBreak        1       The lines are automatically
                                broken between words.

   flexWordEllipsis     2       Truncates text that does not
                                fit in the rectangle and adds
                                ellipsis.

   flexWordBreakEllip   3       Breaks words between lines and
   sis                          adds ellipsis if text doesn't
                                fit in the rectangle.
				

Hierarchical FlexGrid Control: ColIsVisible and RowIsVisible Properties are

Read Only

The ColIsVisible and RowIsVisible properties are read-only properties and cannot be set programmatically. You can use the properties to test whether a column or row is visible, and hide the column or row, if appropriate, as show below:

  With MSHFlexGrid1
     If .ColIsVisible(1) Then .ColWidth(1) = 0
     If .RowIsVisible(1) Then .RowHeight(1) = 0
  End With
				

Hierarchical FlexGrid Control: Additional Settings for GridLines, GridLinesBand, GridLinesFixed, GridLinesHeader, GridLinesIndent, and

GridLinesUnpopulated Properties

Two additional settings are possible for the following properties:

ridLines, GridLinesBand, GridLinesFixed, GridLinesHeader, GridLinesIndent, GridLinesUnpopulated Properties. The possible settings are show in the table below:

   Constant             Value    Description
   ---------------------------------------------------------------
   flexGridDashes       4        Dashed Lines. Sets line style
                                 between cells to dashed lines.

   flexGridDots         5        Dotted Lines. Sets line style
                                 between cells to dotted lines.
				

Remarks:

These settings can be used in addition to flexGridNone, flexGridFlat, flexGridInset and flexGridRaised.

DataRepeater Control: Setting Public Properties Affect only the Current

Control

When creating a user control to be used in a DataRepeater control, be aware that public properties of the control will be set only on the current control (the "live" control with the focus). For example, if you expose the Font property of a user control, at run time, resetting that property (as shown in the example code below) will only affect the current control in the DataRepeater control. The font of repeated controls will not be affected.

  Private Sub Command1_Click()
     ' Only the current control's Font will be affected.
     DataRepeater1.RepeatedControl.FontName = "Courier"
  End Sub
				

The corresponding code in the user control would resemble the following:

  Public Property Get FontName() As String
     FontName = txtProductName.Font.Name
  End Property
  Public Property Let FontName(ByVal newFontName As String)
     txtProductName.Font.Name = newFontName
  End Property
				

TabStrip Control: Separators show only when the Style property =

TabFlatButtons

Separators will only appear on a TabStrip control when the Style property is set to TabFlatButtons. An example is shown below:

  Private Sub Form_Load()
     With TabStrip1
        .Style = tabFlatButtons
        .Separators = True
     End With
  End Sub
				

Data Report Designer: Error in Event Handling Code

In the topic titled Data Report Events, there is an error in code that shows how to handle asynchronous errors. For more information, search online, with Search titles only selected, for "Data Report Events" in the MSDN Library Visual Studio 6.0 documentation.

The code is found under the heading "Error Events' for Asynchronous Events." The code omits a "Select Case ErrObj.ErrorNumber" statement. The corrected code is:

   Private Sub DataReport_Error(ByVal JobType As _
   MSDataReportLib.AsyncTypeConstants, ByVal Cookie As Long, _
    ByVal ErrObj As MSDataReportLib.RptError, ShowError As Boolean)
      Select Case ErrObj.ErrorNumber
         Case rptErrPrinterInfo ' 8555
            MsgBox "A printing error has occurred. " & _
             "You may not have a Printer installed."
            ShowError = False
            Exit Sub
         Case Else ' handle other cases here.
            ShowError = True
      End Select
   End Sub
				

RichTextBox Control: SelPrint Method Has New Argument

The SelPrint method now features a second, optional argument. The syntax and part descriptions are shown below:

Syntax

object.SelPrint(lHDC As Long, [vStartDoc])
				

The SelPrint method syntax has these parts:

   Part        Description
   -----------------------------------------------------
   object      An object expression that evaluates to a
               RichTextbox control.

   lHDC        Long. The device context of the device you
               plan to use to print the contents of the
               control.

   vStartDoc   Boolean. Specifies the behavior of the
               control regarding startdoc and enddoc printer
               control operations, as shown in settings.
				

Settings

The settings for vStartDoc are:

   Constant    Value      Description
   ---------------------------------------------------------------
   True        -1    (Default) The control retains its
                     original behavior and sends startdoc
                     and enddoc commands to the printer.

   False       0     The control doesn't send startdoc and
                     enddoc commands, but sends only
                     startpage and endpage commands to the
                     printer.
				

Remarks:

The argument was added to remedy situations when printers do not print with the default behavior. When the SelPrint method is invoked, both Visual Basic and the RichTextBox control send startdoc and enddoc commands to the printer resulting in a nested pair of startdoc/enddoc commands. Some printers respond only to the first pair of commands and thereby become disabled when the RichTextbox control sends the second pair. In that case, setting the vStartDoc argument to False prevents the second pair of commands from being sent.

Visual Basic 5 Version of MSChart Control Available in Tools Directory

For pre-release users of Visual Basic only:

A Visual Basic 5.0x version of the MSChart control is now included with Visual Basic. If you need a Visual Basic 5 version of the Chart control, and you have installed the pre-release version of the MSChart control, please overwrite the pre-release version with the version contained in the Tools directory of the Visual Basic CD.

Toolbar Control: Style Property Settings Changed

The Style property settings for the Toolbar control have been changed. The help topic for the property lists tbrTransparent and tbrRight as possible settings, however these are not implemented in the current version. The actual possible settings and descriptions are shown below:

   Constant      Value     Description
   --------------------------------------------------------------
   tbrStandard    0      (Default) Standard toolbar.

   tbrFlat        1      Flat. The borders of a button
                         dynamically appear when the cursor
                         hovers over the button.
				

Visual Basic Run-Time Error 720: Attempting to Add Anything Except a

Control to Controls Collection Causes Run-Time Error

Attempting to add an object that is not a control to the Controls collection causes run-time error 720. You can only add Visual Basic intrinsic controls or ActiveX controls to the collection. To reproduce:

1. Create a new Standard Exe. Form1 is created by default.
2. Add the following code:
   

         Private Sub Form_Load ()
            Controls.Add "Excel.Application", "MyExcelApp")
         End Sub
   
   						

3. Run the exe.

Result: You get an error (720): Invalid class string.

Hierarchical FlexGrid Control: Correcting Errors Binding a Recordset to the

HFlexGrid

If you receive the following error when trying to bind the Hierarchical FlexGrid to an ADO Recordset object, "DataSource settings may be incorrect", try changing some of the behavioral properties associated with the ADO Recordset Object or Command. For example, change the CursorLocation property to adUseNone or adUseClient.

Hierarchical FlexGrid Control: How to Change the Font of Individual Bands

Since the same font object is used for the entire grid object, you must create a new font object to change the fonts of individual bands, rather than changing the font directly.

For example, this way will not change the font for the individual band:

   MSHFlexGrid1.FontBand(1).Name = "Arial"
				

Since you are directly modifying the font object, this will change the fonts in all of the bands to Arial.

To change an individual band, first create a new Font object, then assign that Font object to the FontBand property:

  Dim ft As New StdFont
  ft.Name = "Arial"
  Set MSHFlexGrid1.FontBand(1) = ft
				

This will change just the band's font to Arial.

Hierarchical FlexGrid Control: Avoiding the display of duplicate headers

By default, the Hierarchical FlexGrid control uses the first FixedRow in the Hierarchical FlexGrid as a set of headers (which means it displays the names of the fields bound to each column in this row). Since, by default, the HFlexGrid control displays one FixedRow, if you enable the display of headers on Band 0, it will appear as though the header is being duplicated twice. To avoid this, set the FixedRow property to 0, or clear out the text values in the first FixedRow using code.

ADO Data Control: FetchProgress and FetchComplete Events Not Implemented

Although the reference topic for the ADO Data Control includes links to the FetchProgress and FetchComplete events, the events are not implemented for the control.

DataGrid: SizeMode and Size Properties Do Not Accept Value of 2

(dbgNumberOfColumns)

The reference topics for the Split object's SizeMode and Size properties refer to a non-existent property value of 2 (dbgNumberOfColumns). Please ignore this value.

Controls: ImageList Control on Page Designer

When using the ImageList control on a DHTML Page designer, images cannot be added at design time. If you try to use the following code in an uncompiled .dll project, you will get the run-time error: -2147418113 (8000ffff), "Method 'Add' of object images failed".

  Private Sub DHTMLPage_Load()
     ImageList1.ListImages.Add , , LoadPicture("C:\Winnt\winnt.bmp")
  End Sub
				

However, the code will work when the .dll project is compiled.

MSComm Control: EOFEnable Property Doesn't Stop Data Input

The EOFEnable property determines if the OnComm event occurs when an EOF character is detected. Contrary to the documentation for the property, however, input does not stop.

Treeview Control: Node Object's Visible Property is Read-Only

The Visible property of the Treeview control's Node object is a read-only property. If the node is not visible, you can use the EnsureVisible method to make it visible, as shown in the example:

  Private Sub Command1_Click()
     If Not TreeView1.Nodes(10).Visible Then
        TreeView1.Nodes(10).EnsureVisible
     End If
  End Sub
				

SysInfo Control: Constants Not Supported

The reference topics for the following events have lists of constants that identify devices and device data.:

• DeviceArrival Event
• DeviceOtherEvent Event
• DeviceQueryRemove Event
• DeviceQueryRemoveFailed Event
• DeviceRemoveComplete Event
• DeviceRemovePending Event

Contrary to the documentation, however, these constants are not supported by the events or the SysInfo control. The values associated with the constants listed in the help topics are valid, but the constant names are not.

User Control: Binary Persistence of PropertyBag Data Causes Page Designer

to Fail

The PropertyBag saves data in binary format. Due to a known problem with binary persistence and the DHTML page designer, however, such data causes the page designer and Visual Basic to fail. See Page Designer: Binary Persistence Issue for more information.