IEqualityComparer.GetHashCode(Object) Method

Definition

傳回指定物件的雜湊碼。Returns a hash code for the specified object.

public:
 int GetHashCode(System::Object ^ obj);
public int GetHashCode (object obj);
abstract member GetHashCode : obj -> int
Public Function GetHashCode (obj As Object) As Integer

Parameters

obj
Object

要傳回雜湊碼的 ObjectThe Object for which a hash code is to be returned.

Returns

Int32

指定物件的雜湊碼。A hash code for the specified object.

Exceptions

obj 的型別是參考型別,而 objnullThe type of obj is a reference type and obj is null.

Examples

下列程式碼範例示範如何執行不區分大小寫的 IEqualityComparerThe following code example demonstrates the implementation of a case-insensitive IEqualityComparer. 在此範例中,GetHashCode 方法會傳回 Object 類型所提供的雜湊碼。In this example, the GetHashCode method returns the hash code provided by the Object type.

ref class myCultureComparer : IEqualityComparer
{
private:
    CaseInsensitiveComparer^ myComparer;

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

    myCultureComparer(CultureInfo^ myCulture)
    {
        myComparer = gcnew CaseInsensitiveComparer(myCulture);
    }

    virtual bool Equals(Object^ x, Object^ y) 
    {
        if (myComparer->Compare(x, y) == 0)
        {
            return true;
        }
        else
        {
            return false;
        }
    }

    virtual int GetHashCode(Object^ obj)
    {
        return obj->ToString()->ToLower()->GetHashCode();
    }
};
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

Remarks

執行此方法可為物件提供自訂的雜湊碼,其對應于 Equals 方法所提供的自訂相等比較。Implement this method to provide customized hash codes for objects,corresponding to the customized equality comparison provided by the Equals method.

Notes to Implementers

需要執行以確保如果 Equals(Object, Object) 方法會傳回兩個物件 xytrue,則 GetHashCode(Object) x 方法所傳回的值必須等於針對 y所傳回的值。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.

Applies to

See also