ValueType.Equals(Object) ValueType.Equals(Object) ValueType.Equals(Object) ValueType.Equals(Object) Method

定义

指示此实例与指定对象是否相等。Indicates whether this instance and a specified object are equal.

public:
 override bool Equals(System::Object ^ obj);
public override bool Equals (object obj);
override this.Equals : obj -> bool
Public Overrides Function Equals (obj As Object) As Boolean

参数

obj
Object Object Object Object

要与当前实例进行比较的对象。The object to compare with the current instance.

返回

如果 true 和该实例具有相同的类型并表示相同的值,则为 obj;否则为 falsetrue if obj and this instance are the same type and represent the same value; otherwise, false.

示例

下面的示例演示如何使用派生值类型重写 Equals 方法。The following example demonstrates how the Equals method can be overridden by a derived value type.

public ref struct Complex
{
public:
   double m_Re;
   double m_Im;
   virtual bool Equals( Object^ ob ) override
   {
      if ( dynamic_cast<Complex^>(ob) )
      {
         Complex^ c = dynamic_cast<Complex^>(ob);
         return m_Re == c->m_Re && m_Im == c->m_Im;
      }
      else
      {
         return false;
      }
   }

   virtual int GetHashCode() override
   {
      return m_Re.GetHashCode() ^ m_Im.GetHashCode();
   }
};
public struct Complex 
{
    public double m_Re;
    public double m_Im;

    public override bool Equals( object ob ){
        if( ob is Complex ) {
            Complex c = (Complex) ob;
            return m_Re==c.m_Re && m_Im==c.m_Im;
        }
        else {
            return false;
        }
    }

    public override int GetHashCode(){
        return m_Re.GetHashCode() ^ m_Im.GetHashCode();
    }
}
Public Structure Complex
   Private m_Re As Double
   Private m_Im As Double
       
   Public Overloads Function Equals(ob As Object) As Boolean
      If TypeOf ob Is Complex Then
         Dim c As Complex = CType(ob, Complex)
         Return m_Re = c.m_Re And m_Im = c.m_Im
      Else
         Return False
      End If
   End Function
   
   
   Public Overloads Function GetHashCode() As Integer
      Return m_Re.GetHashCode() ^ m_Im.GetHashCode()
   End Function

End Structure

注解

@No__t-0 方法将重写 Object.Equals(Object),并为 .NET Framework 中的所有值类型提供值相等性的默认实现。The ValueType.Equals(Object) method overrides Object.Equals(Object) and provides the default implementation of value equality for all value types in the .NET Framework.

默认实现在当前实例的每个字段上调用 Object.Equals(Object) @no__t,如果所有字段都相等,则返回 trueThe default implementation calls Object.Equals(Object) on each field of the current instance and obj and returns true if all fields are equal.

提示

特别是,如果您的值类型包含属于引用类型的字段,则应重写 Equals(Object) 方法。Particularly if your value type contains fields that are reference types, you should override the Equals(Object) method. 这可以提高性能,并使你能够更好地表示该类型的相等性含义。This can improve performance and enable you to more closely represent the meaning of equality for the type.

@No__t 的说明-0Notes for the Windows 运行时Windows Runtime

Windows 运行时Windows Runtime 结构调用 Equals 方法时,它为不重写 Equals 的值类型提供默认行为。When you call the Equals method on a Windows 运行时Windows Runtime structure, it provides the default behavior for value types that don't override Equals. 这是 .NET Framework 为 @no__t 提供的支持的一部分(请参阅Windows 应用商店应用和 Windows 运行时 .NET Framework 支持)。This is part of the support that the .NET Framework provides for the Windows 运行时Windows Runtime (see .NET Framework Support for Windows Store Apps and Windows Runtime). Windows 运行时Windows Runtime 结构不能重写 Equals,即使它们是用C#或 Visual Basic 编写的,因为它们不能有方法。structures can't override Equals, even if they're written with C# or Visual Basic, because they can't have methods. (此外,@no__t 中的结构不会继承 ValueType。)但是,当你在C#或 Visual Basic 代码中使用它们时,它们看起来有 ToStringEquals 和 @no__t 2 方法,而 .NET Framework 提供这些方法的默认行为。(In addition, structures in the Windows 运行时Windows Runtime itself don't inherit ValueType.) However, they appear to have ToString, Equals, and GetHashCode methods when you use them in your C# or Visual Basic code, and the .NET Framework provides the default behavior for these methods.

适用于