Sometimes in a real scenario, you need to access a function of a VB class in a C# page, so there is nothing different in this scenario. You just need to create the object of the VB class in your C# page and just use it. I will explain it in detail in the following procedure.
Step 1: Create a ASP.NET empty website named "TestApp" using C#.
Step 2: Create a Web Form using C# in the website named "Default.aspx".
Step 3: Create a class file in the website named "MyClass1.vb" using Visual Basic.
Step 4: Write a function of addition in the VB class that accepts 2 integer values and return the addition of both of the values using another integer variable.
Public Function Add(value1 As Integer, value2 As Integer) As Integer
Dim result = (value1 + value2)
Step 5: Call the addition function of the VB class in the C# page by creating the object of MyClass1.
Print the addition value on the page.
MyClass1 obj = new MyClass1 ();
int addition = obj.Add(2, 3);
Run the page to see the output.