Q190249: INFO: VB 6.0 Readme Part 9: DHTML Page Designer Issues
Article: Q190249
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:6.0
Operating System(s):
Keyword(s): kbhtml kbActiveX kbDHTML kbInternet kbPageDesigner kbVBp kbVBp600
Last Modified: 11-JAN-2001
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The information in this article applies to:
- Microsoft Visual Basic Learning Edition for Windows, version 6.0
- Microsoft Visual Basic Professional Edition for Windows, version 6.0
- Microsoft Visual Basic Enterprise Edition for Windows, version 6.0
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SUMMARY
=======
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
MORE INFORMATION
================
DHTML Page Designer Issues
--------------------------
Page Designer Error Messages
----------------------------
There are currently no Help topics for the following error messages:
- "Save internal HTML to File?"
This occurs if you specify a new, existing HTML file in the Property Page.
If you have HTML code in an instance of the Page Designer and you decide to
use a different, existing HTML file with the designer, you must open the
property page and specify the name of the existing file. The Page Designer
must then know what to do with the internal HTML that is currently in the
designer. If you answer Yes to this question, Visual Basic will save the
HTML to a file after you specify a filename.
- "DHTML Page Designers cannot be private"
This occurs if you attempt to change a DHTML Page Designer's Public
property to False. While ActiveX designers can be either public or private,
they must be Public to be accessible in a DHTML application. Private
designers can be useful in certain cases, such as in the Data Environment
when you want to encapsulate your data access logic in the Data
Environment, but not make it public.
- "Reload changed HTML file?"
This occurs if the Page Designer notices that the HTML file referenced by
the designer has changed on disk. This message confirms whether you want to
load the modified HTML back into the designer.
Page Designer: "Me." Not Supported
----------------------------------
You cannot use the "Me" reference in your page designer code to reference
the DHTMLPage object. For example, the documentation frequently shows that
you can write code such as "Me.Document.item". This is not supported.
Instead of using Me, you must use the "DHTMLPage" statement. For example,
instead of Me.Document, you would use DHTMLPage.Document. If the designer
is private, "Me" can be used, but private is not allowed in DHTML pages.
Page Designer: Cannot Access HTML Elements from Forms or External Objects
-------------------------------------------------------------------------
You cannot write code in a form, message box, or other object that
references HTML elements on the page. Page elements are only accessible
within the page itself.
Page Designer: Image SourceFiles are Resolved Incorrectly
---------------------------------------------------------
Often, as you work in the page designer, you will want to reference an
image that is located in the same directory as your current HTML page.
Normally, when you reference such an image, you do not include a path in
the image element's SRC attribute. The lack of a path tells the browser to
pull the image from the page's current directory. For example, you might
enter "myimage.gif" in the SRC property for an image of this type, rather
than specifying "c:\mydhtml\myimage.gif." This is called a relative path,
because it does not specify the full location of the image file.
At design-time, the page designer does not correctly display these images
with relative paths. When you enter such a property value in the SRC
property or display a page that contains such a reference, two things will
happen:
- The image element will appear empty at design time.
- The page designer appends the word "About:" to the value of your SRC
property. For example, you might see "About:myimage.gif."
Despite these problems, the image appears correctly when you run the
project. So you can ignore the "About:" keyword that appears in the SRC
property and the fact that the image doesn't appear in the designer. When
you save the HTML file, the image tag will be written correctly.
Page Designer: Binary Persistence Issue:
Some controls attempt to save some or all of their properties in a binary
format that cannot be directly represented in HTML. Because of this
situation, some control properties may not be saved after you run your
project. In order to correct this problem, set the property at run-time.
The following list shows the known properties for which this problem
occurs:
Tabbed Dialog Control: TabsPerRow property does not persist
Windowless Controls Listbox: List items do not persist
Common Controls: Tabstrip settings do not persist
Common Controls: Toolbar settings do not persist
Common Controls: StatusBar settings do not persist
ADODC Control: ConnectionString property does not persist
In addition, for many controls, font properties do not persist. This
occurrence is the most common manifestation of the binary persistence
problem.
Page Designer:
Type Library Problems are Preventing Some Help Topics from Appearing
--------------------------------------------------------------------
When you begin a page designer project, you will see two DHTML type
libraries in the Object Browser, the DHTMLPAGELIB library, and a
DHTMLProject library.
Help is enabled for the DHTMLPAGELIB library, but not for the DHTMLProject
library. Most elements in DHTMLProject should be available within the other
library. In other cases, type library problems are preventing certain
pieces of the help to appear or function correctly. This happens in the
following cases:
- When you try to access help from the Properties window for an ActiveX
control's properties.
- When you try to access help from the Code Editor window, for the
Document property.
In most cases, you should be able to locate the topic you want through the
index in the MSDN Help viewer.
Page Designer: Modal Prompts Appear Behind Browser in Run Mode
--------------------------------------------------------------
If you add a message box to your DHTML page, the message box appears behind
Internet Explorer when activated in run mode. In addition, you cannot move
Internet Explorer out of the way in order to view the message, because the
message is modal. When you hear the beep that indicates a message is on the
screen, select the Visual Basic application from your taskbar to view and
clear the message.
Page Designer: Do Not Watch Objects of Type HTMLDocument
--------------------------------------------------------
Expanding a watch on objects of type HTMLDocument may cause problems within
the IDE. Avoid watching objects of this type.
Page Designer: Cannot Design Frames Within A Page Designer
----------------------------------------------------------
When you create Web pages in the DHTML Page Designer, you cannot insert
framesets within the page and fill their contents. You can, however,
display the pages you create for your DHTML application within a frameset
created outside of Visual Basic. If you want to design and debug frames,
the process is as follows:
1. In Visual Basic, design the contents of each frame with an individual
DHTML Page Designer.
2. In an external editing program, design the frameset document as a
separate .htm file and save it in the temp directory. Set the SRC
attributes for each frame to point to your content pages, using the
names you defined in their BuildFile properties.
3. In Visual Basic, choose "Start Browser with URL" on the Debugging tab of
the Project Properties dialog box and enter the path of the frameset
file.
4. Enter run mode. Visual Basic launches Internet Explorer and loads the
frameset page you designed in an external program. The frameset document
should then load your page designer pages in the appropriate frames.
5. Debug your application as usual.
Page Designer: Cannot use Visual Basic Code with the SetInterval Method
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If you use the SetInterval method of the Internet Explorer BaseWindow
object on a timer within your DHTML applications, you must set the first
parameter of the method to point to a Javascript or VBScript time routine
contained within the HTML page. This method cannot reference a Visual Basic
routine within your page designer code.
Page Designer: Control Issues
-----------------------------
The following are items to be aware of as you work with ActiveX Controls in
your DHTML applications:
- You must use the compiled version of any ActiveX controls you add to
your DHTML pages.
- You cannot use a DHTML page within an ActiveX Control project in this
release. The reverse is also true -- that is, the ActiveX control
project cannot be part of the project group in which you are working.
The safest and most reliable way to build and debug a user control is to
compile the user control project, then close that project, add the
control to the page designer, and proceed from there. Interactive
debugging and design between the two projects is not possible at this
point.
- When you embed an ActiveX control on a page in your DHTML application,
not all of the appropriate type library information is copied with it.
This can cause errors when you try to access a link in the object
browser to the information for that control, and it can prevent you from
accessing extended properties and methods for the control in the
statement completion window that appears when you write code.
- Some ActiveX controls will not work correctly with the page designer.
You cannot use the following controls in a DHTML page: MS Chart, Script
Debugger, Hierarchical FlexGrid, SrcEdit OC, LayoutDTC, Tabular Data
control, PageNavbarDTC, DBGrid(use DataGrid that ships with VB6) or IE
Popup Window. In addition, you cannot use private or uncompiled user
controls on pages in your DHTML applications. In addition, it is
possible that some controls you have obtained from third parties may not
work correctly with the page designer.
Most controls that work with Internet Explorer 4 should work with the page
designer. If you buy a third-party control that does not work with the page
designer, test it within Internet Explorer and then contact the control
vendor. For information on how to build ActiveX controls that work with the
page designer and Internet Explorer, please see the article "Building
ActiveX Controls for Internet Explorer 4.0," available in your MSDN library
or on Microsoft's Web site in the MSDN Online section.
- If you have an ActiveX control for which you have set the background
transparent, it will appear opaque at design time when added to your
DHTML application.
- If your DHTML page contains a Listview control and you try to access the
ColHeader.Width property, you will encounter an error saying that the
object does not support this property. The property does appear on the
Auto List Members drop-down list, but you should not use it in your
code.
- Some Visual Basic controls, such as the common dialog or the sysinfo
control, are invisible at run-time. If you add one of these objects to
your HTML page, you cannot select it and move it around within the page
after you initially draw it. You can, however, select the control in the
treeview and either delete it or access its properties.
- If you add a File Upload control (FlUpl) to your DHTML designer and you
click it during design-time, it will activate and display the standard
file chooser dialog box. You can cancel this dialog box and move on.
- There is a nonfunctional InnerText property available in the Auto List
Members drop-down list for the horizontal rule element. Do not set a
value for this property as it will produce no result.
- When you add an ActiveX control to your page, the Height and Width
properties do not update automatically as the control is resized in the
designer. To refresh the numbers in the height and width properties,
click in a blank area of the treeview after resizing your control.
- When you click a control in the toolbox and then move the cursor to the
Design pane of the designer, the cursor does not change from an I-beam
to a pointer to indicate that you can click and draw your control. You
can still click and drag your control to the desired shape, even though
the cursor is still an I-beam.
- When you copy controls between two DHTML projects in the same project
group, the Components dialog box is not updated. You will need to set
the necessary references to that control manually.
- If you use the ImageList control, its picture will not be loaded if the
project is Run in debug mode. However, the image will work correctly
when you run the compiled DLL.
Page Designer: Miscellaneous HTML Issues
----------------------------------------
The following are items to be aware of as you create and work with HTML in
the DHTML page designer:
- If your page contains a CHARSET metatag, this tag will be stripped out
when the page is read into the designer. This should not cause a problem
in most pages.
- The column widths you see in tables within the designer may not match
the column widths you see when you run your page in the browser. You may
be able to avoid this problem either by setting your column widths in
percentages rather than pixels, or by making sure the left-most column
does not have a width measurement set for it.
- Do not assign ID property values with greater than 117 characters. If
you do, you may receive an error when running your application.
- If the first paragraph element on your page does not contain text and is
followed by another HTML element, you may see unexpected results if you
delete the first <P> tag. In this case, other elements on the page may
also be deleted.
- You may receive inconsistent results when trying to delete a DIV tag
using the designer's treeview panel. If you have trouble deleting a DIV
tag, use the Launch Editor function and remove the <DIV> and </DIV> tags
manually.
- When you run your project, table borders will appear only for cells that
contain text. You can force a table border to appear for empty cells in
your tables by placing a <BR> tag in each unused table cell.
- Property values set for the TITLE element on your HTML page may not
persist in the property grid after you run the project. However, if you
examine the HTML source code in the browser you will see that your title
properties are still present in the HTML stream.
- Elements on a page are always anchored by the upper left corner.
Therefore, if you resize the element by stretching the top or left
borders, you will see an element of the size you indicated when you
release the cursor but it will still be positioned from the original
top, left corner. This may produce unexpected results. You can avoid
this by first positioning your control with the upper left corner in the
appropriate place, then sizing it correctly.
- You may have difficulty removing font formatting from some elements. For
example, if you add an H1 heading to your page, press ENTER, and type a
few sentences below it, the paragraph will receive the same formatting
as the heading, it will appear large and in bold. You cannot remove this
formatting using the bold icons on the formatting toolbar. You can
remove this kind of incorrect formatting either by using the Launch
Editor feature and manually correcting the formatting tags, or by
changing the style of the selected text in the designer to Normal.
- Some properties that appear in the Properties window for the Document
object are not valid. These properties begin with the letters "on". If
you set a value for any of these properties, you will see no results
based on the value you set when you run the project or examine the HTML
source.
- For a check box HTML element, a property called "Indeterminate" is used
to set the check box to a grayed-out state. However, if you set this
property to True and then click the check box to move it to the blank
state, the Indeterminate property does not reset to False. You can reset
it manually or click a third time to reset the value.
- For absolutely positioned controls with Height and Width properties that
appear in the Properties window, you cannot resize the control by
changing the values of those properties directly. Instead, resize the
control by dragging one of its borders in the designer.
- If you insert an input image element onto your page from the HTML
toolbox, then use the Shape property to change it from another shape to
a polygon, you will receive an error.
- The treeview pane of the designer may not reflect the exact order of
items as they appear in the design pane. The treeview shows the
structural relationship of elements on the page in the order in which
they appear in the HTML stream. The position of an element in the HTML
stream does not always correspond to the position of an element on the
displayed page, because you can change an element's position with
attributes and inline styles. Your page will appear in Internet Explorer
as it does in the design pane of the designer.
Page Designer: Miscellaneous Debugging Issues
---------------------------------------------
The following are items to be aware of as you debug and test your DHTML
applications:
- In the Locals window, functions used in your DHTML application are
listed twice. This may cause difficulty because it allows you to
seemingly set two different values for Booleans.
- Several properties listed in the Locals window will produce an error if
you try to edit their value. These include the following properties:
DHTMLPage.BaseWindow.document.activeElement.all.length
DHTMLPage.BaseWindow.document.activeElement.offsetParent.all.length
DHTMLPage.BaseWindow.document.activeElement.children.length
- If you refresh Internet Explorer while your DHTML project is in break
mode, then you return to run mode in Visual Basic, your breakpoints will
no longer be hit and stop instructions will no longer be followed. Stop
debug mode, then press the F5 key again to begin your debug process a
second time.
Page Designer: Syntax for Navigating Programmatically
-----------------------------------------------------
In the "Navigating in DHTML Applications" topic in the Developing DHTML
Applications section of the Building Internet Applications book, the
documentation states that you can programmatically move between pages by
using this syntax in your code:
Private Function Button1_onclick() As Boolean
BaseWindow.navigate "Project1.DHTMLPage2.html"
End Function
This syntax is incorrect because an underscore rather than a period should
separate the project name and the page name. The correct syntax to use is
shown below:
Private Function Button1_onclick() As Boolean
BaseWindow.navigate "Project1_DHTMLPage2.html"
End Function
Page Designer: OBJECT Tag Insertion
-----------------------------------
In the topic "Testing your DHTML Projects," the documentation states that
an OBJECT tag is inserted into your page during debugging but does not
state that this tag is enclosed in a METADATA tag that is also inserted at
this time. In addition, the following clarifications may be helpful:
- The contents of the OBJECT tag's CODEBASE attribute are filled in during
packaging, when you use the Package and Deployment Wizard to prepare
your project for distribution.
- During debugging, the OBJECT tag is actually inserted into a temporary
copy of the HTML file. The final tag is set up during the packaging
process.
Page Designer:
Cannot CTRL+TAB Through Windows When Page Designer Has Focus
------------------------------------------------------------
When the Page Designer window has focus, you cannot use the CTRL+TAB
keystroke to move through all open windows in the Visual Basic IDE as you
can with other projects.
Page Designer: Cannot Delete a Table if it Contains No Columns
--------------------------------------------------------------
If you delete all of the columns from a table on your page and then try to
delete the table, it will still appear in the treeview pane of the
designer. To delete the table from the treeview, you must delete the
paragraph element under which the table element appears.
Page Designer: When Using Visual SourceSafe with Page Designer Projects,
You Must Manually Check in the Project's .HTM Files
---------------------------------------------------
When you check a DHTML project into Visual SourceSafe, the HTML pages
associated with the project are not automatically checked into the
SourceSafe tree with the rest of the project files. You must manually add
them to the tree as related files.
NOTE: This applies only when you have saved your HTML pages to external
files. If you have saved them within the project there are no .htm files to
check in for your design-time project.
Page Designer:
Unqualified BuildFile Property Results in DLL Building To Desktop
-----------------------------------------------------------------
If you edit the BuildFile property so that it does not specify the drive
and directory in which the file should be placed, the system will build the
resulting files directly to your desktop. Always enter the fully-qualified
path when entering values for this property.
Page Designer: Use of Load Event With Asynchronous Property
-----------------------------------------------------------
In the "Load Event" topic within the Reference section of the Visual Basic
documentation in MSDN, the documentation incorrectly states the following:
"Programmers can use this event when running asynchronously (when the
AsyncLoad property is set to True) as a notification that all elements have
been loaded onto the page."
In fact, this should say that programmers can use the Load event when
running synchronously (when AsyncLoad is set to False) as a notification
that all elements have been loaded.
Page Designer: Property Page Issues
-----------------------------------
The following are items to be aware of as you work in the property pages
for various HTML elements in the DHTML Page Designer:
- Some elements have additional tabs in their property pages that do not
appear when you view the property page in a DHTML project. In many
cases you can get to these tabs even if they are not visible by pressing
the TAB key.
- If you make changes to the custom property page for an ActiveX control
you have added to your DHTML application, you may not always see those
changes reflected in your DHTML project. To correct this problem, close
your DHTML project and recompile the ActiveX control project. Your
changes should then appear in the DHTML project. Repeat this process
each time you make changes to the property page for the control.
- The word "Test" will appear in the body of some property pages. This
will not cause any problems in your application.
Page Designer: Location of Project Files in .CAB Deployment
-----------------------------------------------------------
In the topic "Deploying your DHTML Projects," the documentation states that
the project DLL file, the Visual Basic run-time, and the .dsr and .dsx
files for the project are all placed into the same .cab file during the
deployment process. This is not correct. In fact, the .dsr and .dsx files
for the project are not placed into the .cab.
Page Designer: Name of Save Option Changed
------------------------------------------
In the documentation for the page designer, the procedures for choosing
save options tell you to select a Page Properties dialog box option called
"Save HTML Within the Designer" if you do not want to save to an external
HTML file. This option is actually named "Save HTML as part of the VB
Project."
Page Designer:
Problems Seeing Code Changes When Switching from Compiled to Debug Mode
-----------------------------------------------------------------------
You may, on occasion, encounter a problem where you do not see changes you
have made to the code in your DHTML application when you have run the
compiled DLL, made a change to the code, then entered debug mode. In this
situation, you can try either of the following fixes:
- Clear the Use Existing Browser check box on the Debugging tab of the
Project Properties dialog before you start the debug process, after
making changes to your code.
- Exit the browser after running the compiled DLL, before opening the IDE
to make code changes.
Page Designer: BuildFile Property and HTML File Created
-------------------------------------------------------
By default, the BuildFile property is set to the value of the SourceFile
property. The SourceFile Property is null if you selected "Save HTML inside
the VB Project" in the .DHTMLPage Properties dialog box, so in turn the
BuildFile property is null by default. Selecting "Save HTML in an external
file" in the .DHTMLPage Properties dialog box will set the SourceFile
Property which in turn will set the BuildFile property. Just make sure you
set the BuildFile property and always enter a fully qualified path.
NOTE: You want to store your page as an external HTML file. The DHTML Page
designer has some limitations when it comes to editing your HTML page. If
you don't store your page as an external HTML file you will not be able to
use an external editor on this page.
Page Designer:
Help on Most Language Elements Is Available in the Platform SDK
---------------------------------------------------------------
Most language elements in the page designer are inherited from the Internet
Explorer's document object model. F1 for these elements is not available.
To get help on these topics, open the "Platform SDK" node in the MSDN table
of contents, then open the "Internet/Intranet/Extranet Services" node and
look for the Dynamic HTML section. You can also use the Index to do a
search for the name of a particular language element.
REFERENCES
==========
For additional information, please see the following articles in the Microsoft
Knowledge Base:
Q170164 INFO: VB 6.0 Readme Part 1: Important Issues - Read First!
Q170163 INFO: VB 6.0 Readme Part 2: Data Access/Databinding Issues
Q170162 INFO: VB 6.0 Readme Part 3: Control Issues
Q170161 INFO: VB 6.0 Readme Part 4: Language Issues
Q170160 INFO: VB 6.0 Readme Part 5: Samples Issues
Q190046 INFO: VB 6.0 Readme Part 6: Wizard Issues
Q170158 INFO: VB 6.0 Readme Part 7: Error Message Issues
Q189539 INFO: VB 6.0 Readme Part 8: WebClass Designer Issues
Q170154 INFO: VB 6.0 Readme Part 10: Extensibility Issues
Q170157 INFO: VB 6.0 Readme Part 11: Miscellaneous Issues
Q170156 INFO: VB 6.0 Readme Part 12: Transaction Server (MTS) Issues
Q191792 INFO: VB 6.0 Readme Part 13: Dictionary Object
Q191791 INFO: VB 6.0 Readme Part 14: Visual Component Manager
Q191790 INFO: VB 6.0 Readme Part 15: Application Performance Explorer
Q190256 HOWTO: Show Table Borders for All Cells in DHTML Page Designer
Q190255 BUG: DHTML Page Designer Does Not Insert the <HTML> Tag
Q190254 BUG: Cannot Insert MFC 4.1-Based Controls in DHTML Page Designer
Q190251 BUG: Option Explicit Statement Is Not Added by a DHTML File
Q190250 BUG: DHTML Page Designer Cannot Find the Mshtml.hlp File
Q191183 HOWTO: Navigate Between DHTML Designer Pages
Additional query words:
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Keywords : kbhtml kbActiveX kbDHTML kbInternet kbPageDesigner kbVBp kbVBp600
Technology : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVBA600 kbVB600
Version : WINDOWS:6.0
Issue type : kbinfo
=============================================================================
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