This document discusses how to organize and document classes in C#. It covers coding multiple classes in a single file, using partial classes, namespaces, and XML documentation comments. It also describes the benefits of creating class libraries, which allow classes to be shared across multiple projects through project references rather than code duplication. Documentation comments provide information about classes, methods, properties and parameters to both developers and in Visual Studio tooltips.

1. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 1
Chapter 16
How to organize and
document your classes

2. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 2
Objectives
Applied
1. Add XML documentation to your classes.
2. Create and use a class library.
Knowledge
1. Describe two ways that you can code two or more classes in a
single file.
2. Describe the benefits of creating and using a class library.
3. Describe the use of namespaces.
4. Describe the use of partial classes.

3. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 3
A file with two classes coded one after the other
public class Class1
{
// Body of Class1
}
public class Class2
{
// Body of Class2
}

4. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 4
A file with nested classes
public class OuterClass
{
// code that uses the inner class
InnerClass ic = new InnerClass();
// Body of OuterClass
public class InnerClass
{
// Body of InnerClass
}
}

5. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 5
A Customer class that’s split into two files
The first file
public partial class Customer
{
// Some members of the Customer class
}
The second file
public partial class Customer
{
// The rest of the members of the Customer class
}

6. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 6
A Form class that’s split into two files
The Form1.cs file
public partial class Form1 : Form
{
// The code for the Form1 class that's added
// by the programmer
}
The Form1.designer.cs file
partial class Form1
{
// The code for the Form1 class that's generated
// by Visual Studio
}

7. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 7
Code that declares a namespace
namespace ProductMaintenance
{
public partial class Form1 : Form
{
// Body of Form1 class
}
}

8. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 8
Code that declares nested namespaces
namespace Murach
{
namespace Validation
{
// Body of Validation namespace
}
}
Another way to nest namespaces
namespace Murach.Validation
{
// Body of Validation namespace
}
A using statement that specifies a namespace
using Murach.Validation;

9. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 9
Part of a Validator class with XML documentation
/// <summary>
/// Provides static methods for validating data.
/// </summary>
public class Validator
{
public Validator()
{
}
/// <summary>
/// The title that will appear in dialog boxes.
/// </summary>
public static string Title = "Entry Error";
/// <summary>
/// Checks whether user entered data into a text box.
/// </summary>
/// <param name="textBox">
/// The text box control to be validated.
/// </param>

10. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 10
Part of a Validator class with XML documentation
(cont.)
/// <returns>
/// True if the user has entered data.
/// </returns>
public static bool IsPresent(TextBox textBox)
{
if (textBox.Text == "")
{
MessageBox.Show(textBox.Tag
+ " is a required field.", Title);
textBox.Focus();
return false;
}
return true;
}

11. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 11
XML elements you can use for class
documentation
Element Description
<summary> Provides a general description of a class,
property, method, or other element.
<value> Describes the value of a property.
<returns> Describes the return value of a method.
<param name="name"> Describes a parameter of a method.

12. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 12
A screen tip with documentation for a method
A screen tip with documentation for a parameter

13. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 13
Two projects that use the Validator class
Project 1
Validator
(Validation
class)
Form1
(Form class)
Project 2
Validator
(Validation
class)
Form1
(Form class)

14. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 14
Two projects that access the Validator class via a
class library
Project 1
Form1
(Form class)
ValidationLibrary Project 2
Form1
(Form class)
Validator
(Validation
class)

15. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 15
A class library project

16. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 16
A project with a reference to a class library

17. Murach’s C# 2010, C16 © 2010, Mike Murach & Associates, Inc. Slide 17
A using statement for the validation class library
using Murach.Validation;