Informations
Le sujet que vous avez demandé est indiqué ci-dessous. Toutefois, ce sujet ne figure pas dans la bibliothèque.

Attribute.Match Method

When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

public virtual bool Match(
	Object obj
)

Parameters

obj
Type: System.Object
An Object to compare with this instance of Attribute.

Return Value

Type: System.Boolean
true if this instance equals obj; otherwise, false.

This method determines if one Attribute equals another. Its default implementation is the same as Equals, which performs a value and reference comparison. Override this method to implement support for attribute values, such as flags or bit fields, that consist of components that are meaningful in themselves.

For example, consider an attribute whose value is a binary field divided into a bit field of flags. Two instances of this attribute have one flag in set in common while all the other flags differ. The Equals method cannot determine that the two instances have the same flag set, but the Match method can.

The following code example illustrates the use of Match in the context of Attribute.


using System;
using System.Reflection;

// A custom attribute to allow 2 authors per method.
public class AuthorsAttribute : Attribute
{
  public AuthorsAttribute(string name1, string name2)
  {
     authorName1 = name1;
     authorName2 = name2;
  }

  protected string authorName1;
  protected string authorName2;

  public string AuthorName1
  {
     get { return authorName1; }
     set { authorName1 = AuthorName1; }
  }

  public string AuthorName2
  {
     get { return authorName2; }
     set { authorName2 = AuthorName2; }
  }

  // Use the hash code of the string objects and xor them together.
  public override int GetHashCode()
  {
     return authorName1.GetHashCode() ^ authorName2.GetHashCode();
  }

  // Determine if the object is a match to this one.
  public override bool Match(object obj)
  {
     // Obviously a match.
     if (obj == this)
        return true;

     // Obviously we're not null, so no.
     if (obj == null)
        return false;

     if (obj is AuthorsAttribute)
        // Combine the hash codes and see if they're unchanged.
        return (((AuthorsAttribute)obj).GetHashCode() & GetHashCode())
           == GetHashCode();
     else
        return false;
  }
}

// Add some authors to methods of a class.
public class TestClass1
{
  [Authors("William Shakespeare", "Herman Melville")]
  public void Method1()
  { }

  [Authors("Leo Tolstoy", "John Milton")]
  public void Method2()
  { }
}

// Add authors to a second class's methods.
public class TestClass2
{
  [Authors("William Shakespeare", "Herman Melville")]
  public void Method1()
  { }

  [Authors("Leo Tolstoy", "John Milton")]
  public void Method2()
  { }

  [Authors("William Shakespeare", "John Milton")]
  public void Method3()
  { }
}

class Example
{
  public static void Demo(System.Windows.Controls.TextBlock outputBlock)
  {
     // Get the type for both classes to access their metadata.
     Type clsType1 = typeof(TestClass1);
     Type clsType2 = typeof(TestClass2);

     // Iterate through each method of the first class.
     foreach (MethodInfo mInfo1 in clsType1.GetMethods())
     {
        // Check each method for the Authors attribute.
        AuthorsAttribute authAttr1 = (AuthorsAttribute)
           Attribute.GetCustomAttribute(mInfo1,
           typeof(AuthorsAttribute));
        if (authAttr1 != null)
        {
           // Display the authors.
           outputBlock.Text += String.Format("Method {0} was authored by {1} " +
                          "and {2}.", mInfo1.Name,
                          authAttr1.AuthorName1,
                          authAttr1.AuthorName2) + "\n";
           // Iterate through each method of the second class.
           foreach (MethodInfo mInfo2 in clsType2.GetMethods())
           {
              // Check each method for the Authors attribute.
              AuthorsAttribute authAttr2 = (AuthorsAttribute)
                 Attribute.GetCustomAttribute(mInfo2,
                 typeof(AuthorsAttribute));
              // Compare with the authors in the first class.
              if (authAttr2 != null && authAttr2.Match(authAttr1))
                 outputBlock.Text += String.Format("Method {0} in class {1} " +
                    "was authored by the same team.",
                    mInfo2.Name, clsType2.Name) + "\n";
           }
           outputBlock.Text += "" + "\n";
        }
     }
  }
}

/*
 * Output:
 * Method Method1 was authored by William Shakespeare and Herman Melville.
 * Method Method1 in class TestClass2 was authored by the same team.
 *
 * Method Method2 was authored by Leo Tolstoy and John Milton.
 * Method Method2 in class TestClass2 was authored by the same team.
 */


Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Ajouts de la communauté

Afficher:
© 2014 Microsoft