Guid.CompareTo Method (Object) (System)

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.NET Framework Class Library

Guid.CompareTo Method (Object)

Compares this instance to a specified object and returns an indication of their relative values.

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

Syntax

Visual Basic

Public Function CompareTo ( _
	value As Object _
) As Integer

public int CompareTo(
	Object value
)

Visual C++

public:
virtual int CompareTo(
	Object^ value
) sealed

abstract CompareTo : 
        value:Object -> int 
override CompareTo : 
        value:Object -> int

Parameters

value: Type: System.Object
An object to compare, or null.

Return Value

Type: System.Int32
A signed number indicating the relative values of this instance and value.

Return value	Description
A negative integer	This instance is less than value.
Zero	This instance is equal to value.
A positive integer	This instance is greater than value, or value is null.

Implements

IComparable.CompareTo(Object)

Exceptions

Exception	Condition
ArgumentException	value is not a Guid.

Remarks

Any instance of Guid, regardless of its value, is considered greater than null.

The value parameter must be null or an instance of Guid; otherwise, an exception is thrown.

Examples

The following example demonstrates how to attach and read a Guid object as an attribute on a user-defined class or interface.

Visual Basic


Imports System.Runtime.InteropServices

' Guid for the interface IMyInterface.
<Guid("F9168C5E-CEB2-4faa-B6BF-329BF39FA1E4")> _
Interface IMyInterface
    Sub MyMethod()
End Interface

' Guid for the coclass MyTestClass.
<Guid("936DA01F-9ABD-4d9d-80C7-02AF85C822A8")> _
Public Class MyTestClass
    Implements IMyInterface

    Public Sub MyMethod() Implements IMyInterface.MyMethod
    End Sub

    Public Shared Sub Main()
        Dim IMyInterfaceAttribute As GuidAttribute = CType(Attribute.GetCustomAttribute(GetType(IMyInterface), GetType(GuidAttribute)),
                                                           GuidAttribute)

        ' The Value property of GuidAttribute returns a string. 
        Console.WriteLine("IMyInterface Attribute: " + IMyInterfaceAttribute.Value)

        ' Use the string to create a guid.
        Dim myGuid1 As New Guid(IMyInterfaceAttribute.Value)
        ' Use a byte array to create a guid.
        Dim myGuid2 As New Guid(myGuid1.ToByteArray())

        ' Equals is overridden to perform a value comparison.
        If myGuid1.Equals(myGuid2) Then
            Console.WriteLine("myGuid1 equals myGuid2")
        Else
            Console.WriteLine("myGuid1 does not equal myGuid2")
        End If 

        ' The equality operator can also be used to determine if two guids have same value.
        If myGuid1.ToString() = myGuid2.ToString() Then
            Console.WriteLine("myGuid1 == myGuid2")
        Else
            Console.WriteLine("myGuid1 != myGuid2")
        End If
    End Sub
End Class
' The example displays the following output:
'       IMyInterface Attribute: F9168C5E-CEB2-4faa-B6BF-329BF39FA1E4
'       myGuid1 equals myGuid2
'       myGuid1 == myGuid2


using System;
using System.Runtime.InteropServices;

// Guid for the interface IMyInterface.
[Guid("F9168C5E-CEB2-4faa-B6BF-329BF39FA1E4")]
interface IMyInterface
{
    void MyMethod();
}

// Guid for the coclass MyTestClass.
[Guid("936DA01F-9ABD-4d9d-80C7-02AF85C822A8")]
public class MyTestClass : IMyInterface
{
    public void MyMethod() {}

    public static void Main( string []args )
    {
        GuidAttribute IMyInterfaceAttribute = (GuidAttribute) Attribute.GetCustomAttribute(typeof(IMyInterface), typeof(GuidAttribute));

        // The Value property of GuidAttribute returns a string. 
        System.Console.WriteLine("IMyInterface Attribute: " + IMyInterfaceAttribute.Value );    

        // Using the string to create a guid.
        Guid myGuid1 = new Guid(IMyInterfaceAttribute.Value );
        // Using a byte array to create a guid.
        Guid myGuid2 = new Guid(myGuid1.ToByteArray());

        // Equals is overridden to perform a value comparison.
        if (myGuid1.Equals(myGuid2))
            System.Console.WriteLine("myGuid1 equals myGuid2");
        else
            System.Console.WriteLine("myGuid1 does not equal myGuid2" );

        // Equality operator can also be used to determine if two guids have same value.
        if ( myGuid1 == myGuid2 )
            System.Console.WriteLine( "myGuid1 == myGuid2" );
        else
            System.Console.WriteLine( "myGuid1 != myGuid2" );
    }
}
// The example displays the following output:
//       IMyInterface Attribute: F9168C5E-CEB2-4faa-B6BF-329BF39FA1E4
//       myGuid1 equals myGuid2
//       myGuid1 == myGuid2

Visual C++


using namespace System;
using namespace System::Runtime::InteropServices;

// Guid for the interface IMyInterface.
[Guid("F9168C5E-CEB2-4faa-B6BF-329BF39FA1E4")]
public interface class IMyInterface
{
public:
   void MyMethod();
};


// Guid for the coclass MyTestClass.
[Guid("936DA01F-9ABD-4d9d-80C7-02AF85C822A8")]
public ref class MyTestClass: public IMyInterface
{
public:
   virtual void MyMethod(){}
};

int main()
{
   Attribute^ IMyInterfaceAttribute = Attribute::GetCustomAttribute( IMyInterface::typeid, GuidAttribute::typeid );

   // The Value property of GuidAttribute returns a string. 
   System::Console::WriteLine( String::Concat(  "IMyInterface Attribute: ", (dynamic_cast<GuidAttribute^>(IMyInterfaceAttribute))->Value ) );

   // Using the string to create a guid.
   Guid myGuid1 = Guid(dynamic_cast<GuidAttribute^>(IMyInterfaceAttribute)->Value);

   // Using a byte array to create a guid.
   Guid myGuid2 = Guid(myGuid1.ToByteArray());

   // Equals is overridden to perform a value comparison.
   if ( myGuid1.Equals( myGuid2 ) )
      System::Console::WriteLine(  "myGuid1 equals myGuid2" );
   else
      System::Console::WriteLine(  "myGuid1 not equals myGuid2" );

   // Equality operator can also be used to determine if two guids have same value.
   if ( myGuid1 == myGuid2 )
      System::Console::WriteLine(  "myGuid1 == myGuid2" );
   else
      System::Console::WriteLine(  "myGuid1 != myGuid2" );
}
// The example displays the following output:
//       IMyInterface Attribute: F9168C5E-CEB2-4faa-B6BF-329BF39FA1E4
//       myGuid1 equals myGuid2
//       myGuid1 == myGuid2

Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference

Guid Structure

CompareTo Overload

System Namespace