C# tutorials
10. Adding a class to a project

Note: While reading this page, bear in mind that I'm no computer expert and that the text below may be partly inaccurate. If you find errors or have proposals for improvements, please send me a message and help make this a better page for the benefit of future visitors. To the left, there are links to more C# tutorials.

To complete this tutorial, follow these instructions:

1. Open Visual C# 2010 Express.

2. Click on New Project in the File menu.

3. Choose Windows Forms Application if that option isn't already chosen, change the name if you like and click on OK.

4. Point at Toolbox in the left margin and click on the Auto Hide icon at the top of the window (to keep the window to stay open and easier to work with).

5. Drag a Button to Form 1.

6. Drag a Rich Textbox to Form 1. Resize the textbox if you like.

7. Double-click on the button. The file Form1.cs will open with the caret ready to write code that will run when button 1 is clicked.

8. Write or paste this code where the caret is:

richTextBox1.Text = c1.hello;

9. Write or paste this code right above public Form1():

Class1 c1 = new Class1();

10. Click on Add Class in the Project menu.

11. Choose Class if that option isn't already chosen, keep the name Class1.cs and click on Add.

12. Place the caret right after the first curly brace right below class Class1, press return and write or paste this code where the caret is:

public string hello = "Hello world!";

13. Press F5 to start debugging the program.

14. Click on the button. The text Hello world! should appear in the textbox.

Comment on the first code snippet

c1 means that the string hello belongs to c1 of the type Class1.

Comment on the second code snippet

c1 is a new instance of the class Class1, that is defined in the file Class1.cs.

Comment on the third code snippet

The keyword public makes the string hello accessible to other classes.

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