This documentation is archived and is not being maintained.

cref Attribute (C# Programming Guide)

The cref attribute in an XML documentation tag means "code reference." It specifies that the inner text of the tag is a code element, such as a type, method, or property. Documentation tools like Sandcastle use the cref attributes to automatically generate hyperlinks to the page where the type or member is documented.

The following example shows cref attributes used in <see> tags.


// Save this file as CRefTest.cs
// Compile with: csc CRefTest.cs /doc:Results.xml 

namespace TestNamespace
{
    /// <summary>
    /// TestClass contains several cref examples.
    /// </summary>
    public class TestClass
    {
        /// <summary>
        /// This sample shows how to specify the <see cref="TestClass"/> constructor as a cref attribute.�
        /// </summary>
        public TestClass()
        { }

        /// <summary>
        /// This sample shows how to specify the <see cref="TestClass(int)"/> constructor as a cref attribute.�
        /// </summary>
        public TestClass(int value)
        { }

        /// <summary>
        /// The GetZero method.
        /// </summary>
        /// <example> 
        /// This sample shows how to call the <see cref="GetZero"/> method.
        /// <code>
        /// class TestClass 
        /// {
        ///     static int Main() 
        ///     {
        ///         return GetZero();
        ///     }
        /// }
        /// </code>
        /// </example>
        public static int GetZero()
        {
            return 0;
        }

        /// <summary>
        /// The GetGenericValue method.
        /// </summary>
        /// <remarks> 
        /// This sample shows how to specify the <see cref="GetGenericValue"/> method as a cref attribute.
        /// </remarks>

        public static T GetGenericValue<T>(T para)
        {
            return para;
        }
    }

    /// <summary>
    /// GenericClass.
    /// </summary>
    /// <remarks> 
    /// This example shows how to specify the <see cref="GenericClass{T}"/> type as a cref attribute.
    /// </remarks>
    class GenericClass<T>
    {
        // Fields and members.
    }

    class Program
    {
        static int Main()
        {
            return TestClass.GetZero();
        }
    }
}


When compiled, the program produces the following XML file. Notice that the cref attribute for the GetZero method, for example, has been transformed by the compiler to "M:TestNamespace.TestClass.GetZero". The "M:" prefix means "method" and is a convention that is recognized by documentation tools such as Sandcastle. For a complete list of prefixes, see Processing the XML File (C# Programming Guide).

<?xml version="1.0"?>
<doc>
    <assembly>
        <name>CRefTest</name>
    </assembly>
    <members>
        <member name="T:TestNamespace.TestClass">
            <summary>
            TestClass contains cref examples.
            </summary>
        </member>
        <member name="M:TestNamespace.TestClass.#ctor">
            <summary>
            This sample shows how to specify the <see cref="T:TestNamespace.TestClass"/> constructor as a cref attribute. 
            </summary>
        </member>
        <member name="M:TestNamespace.TestClass.#ctor(System.Int32)">
            <summary>
            This sample shows how to specify the <see cref="M:TestNamespace.TestClass.#ctor(System.Int32)"/> constructor as a cref attribute. 
            </summary>
        </member>
        <member name="M:TestNamespace.TestClass.GetZero">
            <summary>
            The GetZero method.
            </summary>
            <example> 
            This sample shows how to call the <see cref="M:TestNamespace.TestClass.GetZero"/> method.
            <code>
            class TestClass 
            {
                static int Main() 
                {
                    return GetZero();
                }
            }
            </code>
            </example>
        </member>
        <member name="M:TestNamespace.TestClass.GetGenericValue``1(``0)">
            <summary>
            The GetGenericValue method.
            </summary>
            <remarks> 
            This sample shows how to specify the <see cref="M:TestNamespace.TestClass.GetGenericValue``1(``0)"/> method as a cref attribute.
            </remarks>
        </member>
        <member name="T:TestNamespace.GenericClass`1">
            <summary>
            GenericClass.
            </summary>
            <remarks> 
            This example shows how to specify the <see cref="T:TestNamespace.GenericClass`1"/> type as a cref attribute.
            </remarks>
        </member>
    </members>    <members>
        <member name="T:TestNamespace.TestClass">
            <summary>
            TestClass contains two cref examples.
            </summary>
        </member>
        <member name="M:TestNamespace.TestClass.GetZero">
            <summary>
            The GetZero method.
            </summary>
            <example> This sample shows how to call the <see cref="M:TestNamespace.TestClass.GetZero"/> method.
            <code>
            class TestClass 
            {
                static int Main() 
                {
                    return GetZero();
                }
            }
            </code>
            </example>
        </member>
        <member name="M:TestNamespace.TestClass.GetGenericValue``1(``0)">
            <summary>
            The GetGenericValue method.
            </summary>
            <remarks> 
            This sample shows how to specify the <see cref="M:TestNamespace.TestClass.GetGenericValue``1(``0)"/> method as a cref attribute.
            </remarks>
        </member>
        <member name="T:TestNamespace.GenericClass`1">
            <summary>
            GenericClass.
            </summary>
            <remarks> 
            This example shows how to specify the <see cref="T:TestNamespace.GenericClass`1"/> type as a cref attribute.
            </remarks>
        </member>
    </members>
</doc>
Show: