How to call C# function from VB.Net?

Introduction

ClassLibrary(C# Coding)

.Net provides create your own class library code and build into DLL and reuse the DLL file. Here created simple class library function in C# code for return a string.

1. Start new project , from the New Project dialogue box select the class library template under C# project types
2.  Name box, type a name for your Class Library. Example here name it SampleCsharp, then click OK.

4. Then Click ok you can get namespace SampleCsharp and the class(rename the class name as Muhilsample) , it look like this



5. write your code inside the class example i have written one function which get input and display the string with some manipulation string.

6.

 public string DisplayString(string GetString)
        {
           
 string str = "Hello" + GetString + " Hw are you?";
            return
 str;
        }

7. The above code get the input string and add front hello and how are you in the end.
8.  Build the project, it will create a DLL look like this

9. SampleCsharp.dll created , now you can use it in another project.

Window Application(Vb.Net coding)

1. Now add new project from the window, select visual basic under other languages

2. click Project > Add Reference. You should see a dialogue box appear with a few tabs on it. Click the Browse tab. Browse to where you saved your Class Library.

3. Then locate the Bin > Debug folder from above. Your DLL will be in there:

4. Click OK .now have a look at the Solution Explorer on the right, and you can  see it appear on the list of references

5.

6. Now you can use the namespace and their classes in your vb.Net
7.

  Dim obj As New SampleCsharp.MuhilSample
        MessageBox.Show(obj.DisplayString("Muhil"))

8. Create a instance for the SampleCsharp.Muhilsample(its written in C# sharp) but object created in VB.NET

9. call the DisplayString with arguments

10. write the above code in page_load event

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim obj As New SampleCsharp.MuhilSample
        MessageBox.Show(obj.DisplayString("Muhil"))
    End Sub

11. Build and run the application output will be