Part 1: Creating a Class Library (DLL)

In this section, we will learn how to create a simple DLL file

1. Open a New Project as shows below and Select Class Library from the templates.

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Select the File Name and the Location where you want to save this file.

2. This is what you will see on the main window.

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Now create a simple function in the class Class1.

In this case I have created the highlighted function to add two numbers.

3. Now, select Build Solution from the Build Menu in the Menu Bar.

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4. Here is the DLL file created in the Debug folder.

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Now this DLL file can be copied and pasted anywhere and can be used by any number of programs at a given point of time.

Part 2: Using a Class Library (DLL)

In this section, we will learn how to use the DLL file that we have created.

NOTE:

Namespace we used : MyDLL

Class : Class1

Function : addnumbers(int a. int b)

1. Create a new Windows Application.
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2. Build a Simple Windows Form as Shown Below.

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3. Now, we need to add the Reference of the DLL file that we had created earlier.

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4. Select the DLL file from the browse tab.

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5. Now, we will use the class and the namespace of the DLL file.

Click on the button to generate an EventHandler

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Make a Note of the namespace that has been added to the coding.

6. Create a new object of the class. Now add the member function of the class with the help of the Object c.

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7. This is how the event handler will look like.

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8. Now, run the program.And, here is the output.

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This is just a simple dll file created. We can create DLL file for any method and use it anywhere we like.