IEqualityComparer.GetHashCode(Object) Method

public:
 int GetHashCode(System::Object ^ obj);

public int GetHashCode(object obj);

abstract member GetHashCode : obj -> int

Public Function GetHashCode (obj As Object) As Integer

A hash code for the specified object.

The following code example demonstrates the implementation of a case-insensitive IEqualityComparer. In this example, the GetHashCode method returns the hash code provided by the Object type.

class myCultureComparer : IEqualityComparer
{
    public CaseInsensitiveComparer myComparer;

    public myCultureComparer()
    {
        myComparer = CaseInsensitiveComparer.DefaultInvariant;
    }

    public myCultureComparer(CultureInfo myCulture)
    {
        myComparer = new CaseInsensitiveComparer(myCulture);
    }

    public new bool Equals(object x, object y)
    {
        return myComparer.Compare(x, y) == 0;
    }

    public int GetHashCode(object obj)
    {
        return obj.ToString().ToLower().GetHashCode();
    }
}

Public Class myCultureComparer
    Implements IEqualityComparer

    Dim myComparer As CaseInsensitiveComparer

    Public Sub New()
        myComparer = CaseInsensitiveComparer.DefaultInvariant
    End Sub

    Public Sub New(ByVal myCulture As CultureInfo)
        myComparer = New CaseInsensitiveComparer(myCulture)
    End Sub

    Public Function Equals1(ByVal x As Object, ByVal y As Object) _
        As Boolean Implements IEqualityComparer.Equals

        Return myComparer.Compare(x, y) = 0
    End Function

    Public Function GetHashCode1(ByVal obj As Object) _
        As Integer Implements IEqualityComparer.GetHashCode
        Return obj.ToString().ToLower().GetHashCode()
    End Function
End Class

Implement this method to provide customized hash codes for objects, corresponding to the customized equality comparison provided by the Equals method.

Implementations are required to ensure that if the Equals(Object, Object) method returns true for two objects x and y, then the value returned by the GetHashCode(Object) method for x must equal the value returned for y.

• GetHashCode()
• IHashCodeProvider