designing exceptions for custom dll used by third party web sites
I'm designing a class library that will be sent out to the public for use with their applications. It interacts with a custom db system that they need to install on their servers.

I'm having trouble deciding how to throw exceptions from this dll which is mainly a wrapper to the custom db system.

I assume I have to create custom exceptions that can indicate various types of errors, including validations, data integrity errors etc.

This dll will be eventually used by public facing web sites. I would like to provide a good feedback to the end user by throwing proper exceptions so that the site can make a decision to display them or not. But I'm not sure if it is possible to anticipate all the user input errors. In case of an unexcepted event, do I just throw a regular .net exception with the error message? 

I have used many third party dlls that do not give you a clear way to handle the errors and I don't want to be one of them.
designing exceptions for custom dll used by third party web sites
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I'm designing a class library that will be sent out to the public for use with their applications. It interacts with a custom db system that they need to install on their servers.

I'm having trouble deciding how to throw exceptions from this dll which is mainly a wrapper to the custom db system.

I assume I have to create custom exceptions that can indicate various types of errors, including validations, data integrity errors etc.

This dll will be eventually used by public facing web sites. I would like to provide a good feedback to the end user by throwing proper exceptions so that the site can make a decision to display them or not. But I'm not sure if it is possible to anticipate all the user input errors. In case of an unexcepted event, do I just throw a regular .net exception with the error message? 

I have used many third party dlls that do not give you a clear way to handle the errors and I don't want to be one of them.