IEqualityComparer.GetHashCode(Object) 方法

定义

命名空间:

System.Collections

程序集:

System.Runtime.dll

返回指定对象的哈希代码。

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

public int GetHashCode (object obj);

abstract member GetHashCode : obj -> int

Public Function GetHashCode (obj As Object) As Integer

参数

obj

Object

Object，将为其返回哈希代码。

返回

Int32

指定对象的哈希代码。

例外

ArgumentNullException

obj 的类型为引用类型，obj 为 null。

示例

下面的代码示例演示不区分大小写 IEqualityComparer的实现。 在此示例中， GetHashCode 方法返回 类型 Object 提供的哈希代码。

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

注解

实现此方法以提供对象的自定义哈希代码，对应于 方法提供的 Equals 自定义相等性比较。

实施者说明

需要实现，以确保如果Equals(Object, Object)方法返回true两个 对象 x 和 y，则 方法x返回GetHashCode(Object)的值必须等于 为 y返回的值。

另请参阅

• GetHashCode()
• IHashCodeProvider