Convert void to string problem

You never need to "convert" void to string; the question is incorrect. This is a wrong manner of interpretation of compiler messages: if compiler tells you "cannot do A", it does not mean you solve this by doing "A".

Your error message should mean that you're trying to assign a string variable (class/structure field/property) a value returned by a function; and the compile-time return type of the function is not assignment-compatible with the target type, which is System.String.

A special case of this situation is the function returning void. The keyword "void" does not mean any real type; it simply means the method which returns nothing. Such method is called for its side effect and cannot appear in the assignment operation at all.

Therefore, you don't need to "convert" anything — there is nothing to convert. You should start writing code understanding the meaning of every word and delimiter you're writing down.

Start from reading C# manual from the very beginning to the very end doing simple exercises. Right now, you need to proceed really slowly.

—SA