Silverlight users cannot register for MySql.Data.dll inconsistencies

This blog post records people to solve a "user cannot register" the process of the problem

1 Problem Description:

Users can delete, but not register, or modify permissions:

Figure 1 User Registration failure

Figure 2 Error modifying user permissions

2 resolution Process

1) Rough method: Directly replace the correct project

I've replaced the correct access and DataService project with the original error access and DataService, and I still have an error. Even, I will replace the usermanage and dataaccesssilverlight two projects, still do not work.

Figure 3 Several projects that have been replaced (these projects are related to user management)

2) Modify the port number

I have used the new port number to publish the DataService project, also does not work:

Figure 4 Creating a new port number

3) Replace database

I even thought that there might be a problem with the database, so I even replace the database with a correct one, and the problem persists.

4) Debug within DataService Using test data

The three methods mentioned above are not a cure for the symptoms. The most fundamental approach is to debug the service itself.

I had thought of using IE's developer tools to capture requests and responses, but I couldn't understand the specifics of the process, and I didn't see any problems. So the road won't work either.

In the end, it is to be debugged under the DataService project.

First you need to look at the page function definition of the registered User:

Figure 5 Registering a user function

The parameter type of this function is a custom class, not a base data type, so you cannot use parameter debugging. Such as:

Figure 6 Call to register a user function

To solve this problem, we can write a test function:

Figure 7 Test function

?

By tracing the test function, the problem is found here: cmd cannot be converted to Mysqlcommand,cmd after conversion to null

Figure 8 Error: cmd cannot be converted to Mysqlcommand.

It dawned on me that it should be the MySql.Data.dll version number. Later the inspection, found the project under the reference

C:\Program Files (x86) \mysql\connector.net 6.9\assemblies\v4.0

This path is MySql.Data.dll, and its version information is:

Figure 9 Default Library version information

And the correct version is:

Figure 10 Target Library version information

After you find the cause of the problem, re-locate the target library and re-reference it to resolve the issue.

Silverlight users cannot register for MySql.Data.dll inconsistencies