Attribute.GetHashCode-Methode
Gibt den Hashcode für diese Instanz zurück.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Public Overrides Function GetHashCode As Integer
'Usage
Dim instance As Attribute
Dim returnValue As Integer
returnValue = instance.GetHashCode
public override int GetHashCode ()
public:
virtual int GetHashCode () override
public int GetHashCode ()
public override function GetHashCode () : int
Rückgabewert
Ein 32-Bit-Ganzzahl-Hashcode mit Vorzeichen.
Beispiel
Das folgende Codebeispiel veranschaulicht die Verwendung der GetHashCode-Methode im Kontext von Attribute.
Imports System
Imports System.Reflection
Imports System.Collections
Module HashCodeVB
' Visual Basic requires that the AttributeUsage be specified.
' A custom attribute to allow two authors per method.
<AttributeUsage(AttributeTargets.All.Method)> _
Public Class AuthorsAttribute
Inherits Attribute
Public Sub New(ByVal name1 As String, ByVal name2 As String)
myAuthorName1 = name1
myAuthorName2 = name2
End Sub
Protected myAuthorName1 As String
Protected myAuthorName2 As String
Public Property AuthorName1() As String
Get
Return myAuthorName1
End Get
Set(ByVal Value As String)
myAuthorName1 = AuthorName1
End Set
End Property
Public Property AuthorName2() As String
Get
Return myAuthorName2
End Get
Set(ByVal Value As String)
myAuthorName2 = AuthorName2
End Set
End Property
' Use the hash code of the string objects and Xor them together.
Public Overrides Function GetHashCode() As Integer
Return myAuthorName1.GetHashCode() Xor myAuthorName2.GetHashCode()
End Function
End Class
' Provide the author names for each method of the class.
Public Class TestClass
<Authors("Immanuel Kant", "Lao Tzu")> _
Public Sub Method1()
End Sub
<Authors("Jean-Paul Sartre", "Friedrich Nietzsche")> _
Public Sub Method2()
End Sub
<Authors("Immanuel Kant", "Lao Tzu")> _
Public Sub Method3()
End Sub
<Authors("Jean-Paul Sartre", "Friedrich Nietzsche")> _
Public Sub Method4()
End Sub
<Authors("Immanuel Kant", "Friedrich Nietzsche")> _
Public Sub Method5()
End Sub
End Class
Sub Main()
' Get the class type to access its metadata.
Dim clsType As Type = GetType(TestClass)
' Use a hash table to store the hash codes and methods.
Dim hTable As Hashtable = New Hashtable()
Dim mInfo As MethodInfo
' Iterate through all the methods of the class.
For Each mInfo In clsType.GetMethods()
' Get the unique hash code for these authors.
Dim attr As Attribute = Attribute.GetCustomAttribute(mInfo, GetType(AuthorsAttribute))
If Not attr Is Nothing Then
Dim authAttr As AuthorsAttribute = CType(attr, _
AuthorsAttribute)
Dim hCode As Integer = authAttr.GetHashCode()
' See if it's already been added to the hash table.
If hTable.Contains(hCode) Then
Dim o As Object = hTable(hCode)
If TypeOf o Is ArrayList Then
' If so, retrieve the array using the Item syntax.
Dim al As ArrayList = CType(o, ArrayList)
' Add the method to the array list.
al.Add(mInfo.Name)
' Put the edited array list back into the table.
hTable(hCode) = al
End If
' This is the first occurrence of this hash code.
Else
' Create a new array list.
Dim al As ArrayList = New ArrayList()
' Add the method name as the first entry.
al.Add(mInfo.Name)
' Add the new hash code and array list to the table.
hTable.Add(hCode, al)
End If
End If
Next
' Get the hash table's enumerator and iterate through the table.
Dim dictEnum As IDictionaryEnumerator = hTable.GetEnumerator
While dictEnum.MoveNext()
' Get the array list for this iteration.
Dim o As Object = dictEnum.Value
If TypeOf o Is ArrayList Then
Dim al As ArrayList = CType(o, ArrayList)
Dim i As Integer
' Access each element of the array.
for i = 0 to al.Count - 1
' For the first element, retrieve the author names.
If i = 0 Then
Dim methodName as Object = al(i)
' Get the metadata for the method.
Dim mInfo2 As MethodInfo = _
clsType.GetMethod(CType(methodName, String))
' Retrieve the Authors attribute again.
Dim attr As Attribute = Attribute.GetCustomAttribute( _
mInfo2, GetType(AuthorsAttribute))
If Not attr Is Nothing And _
TypeOf attr Is AuthorsAttribute Then
' Convert the attribute to access its data.
Dim authAttr As AuthorsAttribute = _
CType(attr, AuthorsAttribute)
' Display the author's names.
Console.WriteLine("Authors: {0}, {1}", _
authattr.AuthorName1, authattr.AuthorName2)
Else
Console.WriteLine("The authors could not " + _
"be retrieved.")
End If
End If
' Display each method authored by this team.
Console.WriteLine(al(i))
Next i
Console.WriteLine("")
End If
End While
End Sub
End Module
using System;
using System.Reflection;
using System.Collections;
namespace HashCodeCS
{
// A custom attribute to allow two 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();
}
}
// Provide the author names for each method of the class.
public class TestClass
{
[Authors("Immanuel Kant", "Lao Tzu")]
public void Method1()
{}
[Authors("Jean-Paul Sartre", "Friedrich Nietzsche")]
public void Method2()
{}
[Authors("Immanuel Kant", "Lao Tzu")]
public void Method3()
{}
[Authors("Jean-Paul Sartre", "Friedrich Nietzsche")]
public void Method4()
{}
[Authors("Immanuel Kant", "Friedrich Nietzsche")]
public void Method5()
{}
}
class DemoClass
{
static void Main(string[] args)
{
// Get the class type to access its metadata.
Type clsType = typeof(TestClass);
// Use a hash table to store the hash codes and methods.
Hashtable hTable = new Hashtable();
// Iterate through all the methods of the class.
foreach(MethodInfo mInfo in clsType.GetMethods())
{
// Get the Authors attribute for the method if it exists.
AuthorsAttribute authAttr =
(AuthorsAttribute)Attribute.GetCustomAttribute(
mInfo, typeof(AuthorsAttribute));
if (authAttr != null)
{
// Get the unique hash code for these authors.
int hCode = authAttr.GetHashCode();
// See if it's already been added to the hash table.
if (hTable.Contains(hCode))
{
// If so, retrieve the array using the Item syntax.
ArrayList al = (ArrayList)hTable[hCode];
// Add the method to the array list.
al.Add(mInfo.Name);
// Put the edited array list back into the table.
hTable[hCode] = al;
}
// This is the first occurrence of this hash code.
else
{
// Create a new array list.
ArrayList al = new ArrayList();
// Add the method name as the first entry.
al.Add(mInfo.Name);
// Add the new hash code and array list to the table.
hTable.Add(hCode, al);
}
}
}
// Get the hash table's enumerator and iterate through the table.
IDictionaryEnumerator dictEnum = hTable.GetEnumerator();
while (dictEnum.MoveNext())
{
// Get the array list for this iteration.
ArrayList al = (ArrayList)dictEnum.Value;
// Access each element of the array.
for (int i=0; i<al.Count; i++)
{
// For the first element, retrieve the author names.
if (i == 0)
{
// Get the metadata for the method.
MethodInfo mInfo = clsType.GetMethod((String)al[i]);
// Retrieve the Authors attribute again.
AuthorsAttribute authAttr =
(AuthorsAttribute)Attribute.GetCustomAttribute(
mInfo, typeof(AuthorsAttribute));
// Display the authors names.
if (authAttr != null)
Console.WriteLine("Authors: {0}, {1}",
authAttr.AuthorName1, authAttr.AuthorName2);
else
Console.WriteLine("The authors could not be retrieved.");
}
// Display each method authored by this team.
Console.WriteLine(al[i]);
}
Console.WriteLine("");
}
}
}
}
using namespace System;
using namespace System::Reflection;
using namespace System::Collections;
// A custom attribute to allow two authors per method.
public ref class AuthorsAttribute: public Attribute
{
public:
AuthorsAttribute( String^ name1, String^ name2 )
{
authorName1 = name1;
authorName2 = name2;
}
protected:
String^ authorName1;
String^ authorName2;
public:
property String^ AuthorName1
{
String^ get()
{
return authorName1;
}
void set( String^ value )
{
authorName1 = value;
}
}
property String^ AuthorName2
{
String^ get()
{
return authorName2;
}
void set( String^ value )
{
authorName2 = value;
}
}
// Use the hash code of the string objects and xor them together.
virtual int GetHashCode() override
{
return authorName1->GetHashCode() ^ authorName2->GetHashCode();
}
};
// Provide the author names for each method of the class.
public ref class TestClass
{
public:
[Authors("Immanuel Kant","Lao Tzu")]
void Method1(){}
[Authors("Jean-Paul Sartre","Friedrich Nietzsche")]
void Method2(){}
[Authors("Immanuel Kant","Lao Tzu")]
void Method3(){}
[Authors("Jean-Paul Sartre","Friedrich Nietzsche")]
void Method4(){}
[Authors("Immanuel Kant","Friedrich Nietzsche")]
void Method5(){}
};
int main()
{
// Get the class type to access its metadata.
Type^ clsType = TestClass::typeid;
// Use a hash table to store the hash codes and methods.
Hashtable^ hTable = gcnew Hashtable;
// Iterate through all the methods of the class.
IEnumerator^ myEnum = clsType->GetMethods()->GetEnumerator();
while ( myEnum->MoveNext() )
{
MethodInfo^ mInfo = safe_cast<MethodInfo^>(myEnum->Current);
// Get the Authors attribute for the method if it exists.
AuthorsAttribute^ authAttr = dynamic_cast<AuthorsAttribute^>(Attribute::GetCustomAttribute( mInfo, AuthorsAttribute::typeid ));
if ( authAttr != nullptr )
{
// Get the unique hash code for these authors.
int hCode = authAttr->GetHashCode();
// See if it's already been added to the hash table.
if ( hTable->Contains( hCode ) )
{
// If so, retrieve the array using the Item syntax.
ArrayList^ al = dynamic_cast<ArrayList^>(hTable[ hCode ]);
// Add the method to the array list.
al->Add( mInfo->Name );
// Put the edited array list back into the table.
hTable[ hCode ] = al;
}
// This is the first occurrence of this hash code.
else
{
// Create a new array list.
ArrayList^ al = gcnew ArrayList;
// Add the method name as the first entry.
al->Add( mInfo->Name );
// Add the new hash code and array list to the table.
hTable->Add( hCode, al );
}
}
}
// Get the hash table's enumerator and iterate through the table.
IDictionaryEnumerator^ dictEnum = hTable->GetEnumerator();
while ( dictEnum->MoveNext() )
{
// Get the array list for this iteration.
ArrayList^ al = dynamic_cast<ArrayList^>(dictEnum->Value);
// Access each element of the array.
for ( int i = 0; i < al->Count; i++ )
{
// For the first element, retrieve the author names.
if ( i == 0 )
{
// Get the metadata for the method.
MethodInfo^ mInfo = clsType->GetMethod( dynamic_cast<String^>(al[ i ]) );
// Retrieve the Authors attribute again.
AuthorsAttribute^ authAttr = dynamic_cast<AuthorsAttribute^>(Attribute::GetCustomAttribute( mInfo, AuthorsAttribute::typeid ));
// Display the authors names.
if ( authAttr != nullptr )
Console::WriteLine( "Authors: {0}, {1}", authAttr->AuthorName1, authAttr->AuthorName2 );
else
Console::WriteLine( "The authors could not be retrieved." );
}
// Display each method authored by this team.
Console::WriteLine( al[ i ] );
}
Console::WriteLine( "" );
}
}
package HashCodeJSL;
import System.*;
import System.Reflection.*;
import System.Collections.*;
// A custom attribute to allow two authors per method.
/** @attribute System.AttributeUsageAttribute(AttributeTargets.Method)
*/
public class AuthorsAttribute extends Attribute
{
public AuthorsAttribute(String name1, String name2)
{
authorName1 = name1;
authorName2 = name2;
} //AuthorsAttribute
protected String authorName1;
protected String authorName2;
/** @property
*/
public String get_AuthorName1()
{
return authorName1;
} //get_AuthorName1
/** @property
*/
public void set_AuthorName1(String value)
{
authorName1 = value;
} //set_AuthorName1
/** @property
*/
public String get_AuthorName2()
{
return authorName2;
} //get_AuthorName2
/** @property
*/
public void set_AuthorName2(String value)
{
authorName2 = value;
} //set_AuthorName2
// Use the hash code of the string objects and xor them together.
public int GetHashCode()
{
return authorName1.GetHashCode() ^ authorName2.GetHashCode();
} //GetHashCode
} //AuthorsAttribute
// Provide the author names for each method of the class.
public class TestClass
{
/** @attribute Authors("Immanuel Kant", "Lao Tzu")
*/
public void Method1()
{
} //Method1
/** @attribute Authors("Jean-Paul Sartre", "Friedrich Nietzsche")
*/
public void Method2()
{
} //Method2
/** @attribute Authors("Immanuel Kant", "Lao Tzu")
*/
public void Method3()
{
} //Method3
/** @attribute Authors("Jean-Paul Sartre", "Friedrich Nietzsche")
*/
public void Method4()
{
} //Method4
/** @attribute Authors("Immanuel Kant", "Friedrich Nietzsche")
*/
public void Method5()
{
} //Method5
} //TestClass
class DemoClass
{
public static void main(String[] args)
{
// Get the class type to access its metadata.
Type clsType = TestClass.class.ToType();
// Use a hash table to store the hash codes and methods.
Hashtable hTable = new Hashtable();
// Iterate through all the methods of the class.
for (int iCtr = 0; iCtr < clsType.GetMethods().length; iCtr++) {
MethodInfo mInfo = (MethodInfo)clsType.GetMethods()[iCtr];
// Get the Authors attribute for the method if it exists.
AuthorsAttribute authAttr = (AuthorsAttribute)Attribute.
GetCustomAttribute(mInfo, AuthorsAttribute.class.ToType());
if (authAttr != null) {
// Get the unique hash code for these authors.
int hCode = authAttr.GetHashCode();
// See if it's already been added to the hash table.
if (hTable.Contains((Int32)hCode)) {
// If so, retrieve the array using the Item syntax.
ArrayList al = (ArrayList)hTable.get_Item((Int32)hCode);
// Add the method to the array list.
al.Add(mInfo.get_Name());
// Put the edited array list back into the table.
hTable.set_Item((Int32)hCode, al);
}
// This is the first occurrence of this hash code.
else {
// Create a new array list.
ArrayList al = new ArrayList();
// Add the method name as the first entry.
al.Add(mInfo.get_Name());
// Add the new hash code and array list to the table.
hTable.Add((Int32)hCode, al);
}
}
}
// Get the hash table's enumerator and iterate through the table.
IDictionaryEnumerator dictEnum = hTable.GetEnumerator();
while (dictEnum.MoveNext()) {
// Get the array list for this iteration.
ArrayList al = (ArrayList)dictEnum.get_Value();
// Access each element of the array.
for (int i = 0; i < al.get_Count(); i++) {
// For the first element, retrieve the author names.
if (i == 0) {
// Get the metadata for the method.
MethodInfo mInfo = clsType.GetMethod((String)al.
get_Item(i));
// Retrieve the Authors attribute again.
AuthorsAttribute authAttr = (AuthorsAttribute)Attribute.
GetCustomAttribute(mInfo,
AuthorsAttribute.class.ToType());
// Display the authors names.
if (authAttr != null) {
Console.WriteLine("Authors: {0}, {1}",authAttr.
get_AuthorName1(), authAttr.get_AuthorName2());
}
else {
Console.WriteLine("The authors could not be "
+ "retrieved.");
}
}
// Display each method authored by this team.
Console.WriteLine(al.get_Item(i));
}
Console.WriteLine("");
}
} //main
} //DemoClass
import System;
import System.Reflection;
import System.Collections;
package HashCodeJS {
// A custom attribute to allow 2 authors per method.
public AttributeUsage(AttributeTargets.Method) class AuthorsAttribute extends Attribute {
public function AuthorsAttribute(name1 : String, name2 : String) {
authorName1 = name1;
authorName2 = name2;
}
protected var authorName1 : String;
protected var authorName2 : String;
public function get AuthorName1() : String {
return authorName1;
}
public function set AuthorName1(AuthorName1 : String) {
authorName1 = AuthorName1;
}
public function get AuthorName2() : String{
return authorName2;
}
public function set AuthorName2(AuthorName2 : String) {
authorName2 = AuthorName2;
}
// Use the hash code of the string objects and xor them together.
public override function GetHashCode() : int {
return authorName1.GetHashCode() ^ authorName2.GetHashCode();
}
}
// Provide the author names for each method of the class.
public class TestClass {
public AuthorsAttribute("Immanuel Kant", "Lao Tzu")
function Method1()
{}
public AuthorsAttribute("Jean-Paul Sartre", "Friedrich Nietzche")
function Method2()
{}
public AuthorsAttribute("Immanuel Kant", "Lao Tzu")
function Method3()
{}
public AuthorsAttribute("Jean-Paul Sartre", "Friedrich Nietzche")
function Method4()
{}
public AuthorsAttribute("Immanuel Kant", "Friedrich Nietzche")
function Method5()
{}
}
class DemoClass {
static function Main() {
// Get the class type to access its metadata.
var testclass : TestClass = new TestClass();
var clsType : Type = testclass.GetType();
// Use a hash table to store the hash codes and methods.
var hTable : Hashtable = new Hashtable();
// Iterate through all the methods of the class.
var mInfo : MethodInfo[] = clsType.GetMethods()
for (var i : int = 0; i < mInfo.length; i++) {
// Get the Authors attribute for the method if it exists.
var attr : Attribute = Attribute.GetCustomAttribute(mInfo[i], AuthorsAttribute);
if (attr != null) {
// Get the unique hash code for these authors.
var hCode : int = attr.GetHashCode();
// See if it's already been added to the hash table.
if (hTable.Contains(hCode)) {
// If so, retrieve the array import the Item syntax.
var al : ArrayList = ArrayList(hTable[hCode]);
// Add the method to the array list.
al.Add(mInfo[i].Name);
// Put the edited array list back into the table.
hTable[hCode] = al;
}
// This is the first occurrence of this hash code.
else {
// Create a new array list.
var al2 : ArrayList = new ArrayList();
// Add the method name as the first entry.
al2.Add(mInfo[i].Name);
// Add the new hash code and array list to the table.
hTable.Add(hCode, al2);
}
}
}
// Get the hash table's enumerator and iterate through the table.
var dictEnum : IDictionaryEnumerator = hTable.GetEnumerator();
while (dictEnum.MoveNext()) {
// Get the array list for this iteration.
var al3 : ArrayList = ArrayList(dictEnum.Value);
// Access each element of the array.
for (var j : int = 0; j < al3.Count; j++) {
// For the first element, retrieve the author names.
if (j == 0) {
// Get the metadata for the method.
var mInfo2 : MethodInfo = clsType.GetMethod(String(al3[j]));
// Retrieve the Authors attribute again.
var attr2 : Attribute =
Attribute.GetCustomAttribute(mInfo2,
AuthorsAttribute);
// Display the authors names.
if (attr2 != null)
Console.WriteLine("Authors: {0}, {1}",
AuthorsAttribute(attr2).AuthorName1,
AuthorsAttribute(attr2).AuthorName2);
else
Console.WriteLine("The authors could not be retrieved.");
}
// Display each method authored by this team.
Console.WriteLine(al3[j]);
}
Console.WriteLine("");
}
}
}
}
/*
* Output:
* Authors: Jean-Paul Sartre, Friedrich Nietzche
* Method4
* Method2
* Authors: Immanuel Kant, Lao Tzu
* Method3
* Method1
* Authors: Immanuel Kant, Friedrich Nietzche
* Method5
*/
HashCodeJS.DemoClass.Main();
Plattformen
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
.NET Compact Framework
Unterstützt in: 2.0, 1.0