INFO: VB 6.0 Readme Part 3: Control Issues

The information below includes the documentation and workarounds for Visual Basic 6.0. This information can also be found in the README.htm file that ships with Visual Basic 6.0 on the Visual Basic 6.0 CD-ROM. Please see the REFERENCES section of this article for a list of the Microsoft Knowledge Base articles relating to the Visual Basic 6.0 readme.

Following is a list of all parts of the readme file:

Part 1. Important Issues - Please Read First!
Part 2. Data Access Issues and DataBinding Tips
Part 3. Control Issues
Part 4. Language Issues
Part 5. Samples Issues
Part 6. Wizard Issues
Part 7. Error Message Issues
Part 8. WebClass Designer Issues
Part 9. DHTML Page Designer Issues
Part 10. Extensibility issues
Part 11. Miscellaneous Issues
Part 12. Microsoft Transaction Server (MTS) Issues
Part 13. Dictionary Object
Part 14. Visual Component Manager
Part 15. Application Performance Manager

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

The ColWordWrapOption property syntax has these parts:

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

Syntax

The ColWordWrapOption property syntax has these parts:

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

Syntax

The ColWordWrapOption property syntax has these parts:

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

Syntax

The ColWordWrapOptionFixed property syntax has these parts:

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

Syntax
The ColWordWrapOptionFixed property syntax has these parts:

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

Syntax
The ColWordWrapOptionHeader property syntax has these parts:

Settings
The settings for integer are:

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:

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:

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.

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

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:

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:

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

The SelPrint method syntax has these parts:

Settings

The settings for vStartDoc are:

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:

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:

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:

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".

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:

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.

For additional information, please see the following articles in the Microsoft Knowledge Base: