Attributes

using System;
using System.Reflection;
using System.Collections;

// The IsTested class is a user-defined custom attribute class.
// It can be applied to any declaration including
// - types (struct, class, enum, delegate)
// - members (methods, fields, events, properties, indexers)
// It is used with no arguments.
public class IsTestedAttribute : Attribute
{
public override string ToString()
{
return "Is Tested";
}
}

// The AuthorAttribute class is a user-defined attribute class.
// It can be applied to classes and struct declarations only.
// It takes one unnamed string argument (the author's name).
// It has one optional named argument Version, which is of type int.
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct)]
public class AuthorAttribute : Attribute
{
// This constructor specifies the unnamed arguments to the attribute class.
public AuthorAttribute(string name)
{
this.name = name;
this.version = 0;
}

// This property is readonly (it has no set accessor)
// so it cannot be used as a named argument to this attribute.
public string Name
{
get
{
return name;
}
}

// This property is read-write (it has a set accessor)
// so it can be used as a named argument when using this
// class as an attribute class.
public int Version
{
get
{
return version;
}
set
{
version = value;
}
}

public override string ToString()
{
string value = "Author : " + Name;
if (version != 0)
{
value += " Version : " + Version.ToString();
}
return value;
}

private string name;
private int version;
}

// Here you attach the AuthorAttribute user-defined custom attribute to
// the Account class. The unnamed string argument is passed to the
// AuthorAttribute class's constructor when creating the attributes.
[Author("Joe Programmer")]
class Account
{
// Attach the IsTestedAttribute custom attribute to this method.
[IsTested]
public void AddOrder(Order orderToAdd)
{
orders.Add(orderToAdd);
}

private ArrayList orders = new ArrayList();
}

// Attach the AuthorAttribute and IsTestedAttribute custom attributes
// to this class.
// Note the use of the 'Version' named argument to the AuthorAttribute.
[Author("Jane Programmer", Version = 2), IsTested()]
class Order
{
// add stuff here ...
}

class MainClass
{
private static bool IsMemberTested(MemberInfo member)
{
foreach (object attribute in member.GetCustomAttributes(true))
{
if (attribute is IsTestedAttribute)
{
return true;
}
}
return false;
}

private static void DumpAttributes(MemberInfo member)
{
Console.WriteLine("Attributes for : " + member.Name);
foreach (object attribute in member.GetCustomAttributes(true))
{
Console.WriteLine(attribute);
}
}

public static void Main()
{
// display attributes for Account class
DumpAttributes(typeof(Account));

// display list of tested members
foreach (MethodInfo method in (typeof(Account)).GetMethods())
{
if (IsMemberTested(method))
{
Console.WriteLine("Member {0} is tested!", method.Name);
}
else
{
Console.WriteLine("Member {0} is NOT tested!", method.Name);
}
}
Console.WriteLine();

// display attributes for Order class
DumpAttributes(typeof(Order));

// display attributes for methods on the Order class
foreach (MethodInfo method in (typeof(Order)).GetMethods())
{
if (IsMemberTested(method))
{
Console.WriteLine("Member {0} is tested!", method.Name);
}
else
{
Console.WriteLine("Member {0} is NOT tested!", method.Name);
}
}
Console.WriteLine();
}
}