Frequently asked questions

CLASSES

How can I access a class from a different program, so that it can be used in the program.  Importing Class References.  Drew Moffit (Spring 2008)

WEB APPLICATIONS

What causes the Security Error "Access Denied" when accessing data in a Web Service (Kyle)? Access Denied Error

What causes a Login Failure in Web Applications and how can the problem be solved (Kyle)? Login Failure

How does a postback work in VB.Net (Dr. Mc)? Here's how!

Index of  0 error with two table database Web application--what causes it and how can it be corrected (Andrea)?  Index of 0

The debugger will not start with my Web application on the Web server.  What can I do (David)? Solution

Copied web application to another computer and it produces an error message that says the debugger cannot be started. Did you copy it first to the desktop, then to the wwwroot folder?  If you did, here is your solution.  Paul Bradley (Fall 2005)

WEB SERVICES

How do I create a web service (Dr. Mc?  See this article

What causes the Web Service 401 Error and what can I do about it (Mario)?  401 Error

Cannot get my Web Service that connects to a SQL server database to work!  Here is the fix.  The SQL Fix. (Keith Gibb 11/3/05)

Cannot get my Web Service that connects to an Access database to work!  Here is the fix for that one, too. Access WS Fix. (Keith Gibb 11/3/05)

MOBILE WEB APPLICATIONS

Cannot get details to show AND the back button to work properly when viewing record details based on a selection from the objectlist control.

Solution:  For this to work properly, the database must be placed somewhere besides the project Bin folder--place it outside the project folder, make sure that enableviewstate is set to true for the objectlist control, and check for postback before binding in the load procedure as follows:

             if ispostback=false then
                   me.databind
            end if

 (Keith Gibb and Paul Bradley--12/12/05)

MSDE AND SQL SERVER

MSDE is installed, but the SQL server does not show up in VB.Net.  What can be done to correct this problem?

  1. Select Start button

  2. Select Settings

  3. Select Network Connections

  4. Right click your network connection icon and select Properties

  5. Check and see if you have File and Print sharing for Microsoft networks.  If not, then:

  1. Click the Install Button

  2. Click the Service Icon

  3. Install the file and print sharing for microsoft. 

You follow pretty much the same instructions for installing MS client for Windows Network, but it is found under "Client" rather than "Service."

Lee Stevens told me this was a remedy for the server not showing up in VB.Net. 

2/9/05  NEW: From Mario Antunes--You must have VB.Net Professional.  The server icon and associated services are not available with the VB.Net Standard Edition.

Web Server Not Running ASP.Net Version 1.1...  Specific Error Message: "Visual Studio has detected that the specified Web Server is not running ASP.NET version 1.1. You will be unable to run ASP.NET Web applications or services.".  Solution. SQL Server Not Running. (12/9/05 by Paul Bradley)

USER CONTROLS

How do I make the calendar in a calendar control occupy the whole screen (David)? Here' how!

How do I add a user control to the Toolbox (Andrea)? Adding User Control

DATABASE

How do I change my connection when I move my DB stuff from one computer to the next (SQL connection)?  Here's how!   (Keith Gibb 9-20-2005)

How do I combine fields in a database table to make a single field (Mario)?  Here it is!

Working with multiple tables--Error: Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints. Cause of this error--violating referential integrity! Error and solution!

Your Data Adapter and/or Dataset (dsDummy1 or whatever you named it) disappear after you created them.  What causes the problem and what can be done to fix it? Missing da or ds

Error indicating that child list cannot be created from DB table.  Error, cause and solution!

Error:  Binding a text box to a field in a dataset passed from the data tier.  Controls fill with one record, but will not move forward or backward (via binding manger and next previous buttons) to other records.  Solution! (Justin Harper)

Error: Bound control with Visible Property set to false--does not work!  See explanation.

Acknowledgements:  Thanks to Mario Antunes, David Ingram,  Kyle Uptergrove and Andrea Holloway, Cody Crisp, Jimmy Welch, Keith Gibb, Justin Harper, Christina Lowcock, and Paul Bradley for their contributions to the FAQs page.