I have a DLL file. How can I view the functions in that DLL?
Use dotPeek by JetBrains.
https://www.jetbrains.com/decompiler/
dotPeek is a free tool based on ReSharper. It can reliably decompile any .NET assembly into C# or IL code.
You may try the Object Browser in Visual Studio.
Select Edit Custom Component Set. From there, you can choose from a variety of .NET, COM or project libraries or just import external dlls via Browse.