ValueType.Equals(Object) 方法


指示這個執行個體和指定的物件是否相等。Indicates whether this instance and a specified object are equal.

 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



要與目前執行個體比較的物件。The object to compare with the current instance.


如果 true 和這個執行個體為同型別並表示相同的值,則為 obj,否則為 falsetrue if obj and this instance are the same type and represent the same value; otherwise, false.


下列範例示範如何使用衍生的實值型別來覆寫 Equals 方法。The following example demonstrates how the Equals method can be overridden by a derived value type.

public ref struct Complex
   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;
         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
         Return False
      End If
   End Function
   Public Overloads Function GetHashCode() As Integer
      Return m_Re.GetHashCode() ^ m_Im.GetHashCode()
   End Function

End Structure


ValueType.Equals(Object) 方法會覆寫 Object.Equals(Object),並為 .NET Framework 中的所有實值型別提供實值相等的預設執行。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.

預設的實值會呼叫目前實例之每個欄位上的 Object.Equals(Object),並 obj 並在所有欄位相等時傳回 trueThe default implementation calls Object.Equals(Object) on each field of the current instance and obj and returns true if all fields are equal.


特別是當您的實值型別包含屬於參考型別的欄位時,您應該覆寫 Equals(Object) 方法。Particularly if your value type contains fields that are reference types, you should override the Equals(Object) method. 這可以改善效能,並讓您更清楚地表示類型的相等意義。This can improve performance and enable you to more closely represent the meaning of equality for the type.

Windows 執行階段Windows Runtime 的注意事項Notes for the Windows 執行階段Windows Runtime

當您在 Windows 執行階段Windows Runtime 結構上呼叫 Equals 方法時,它會為不會覆寫 Equals的實數值型別提供預設行為。When you call the Equals method on a Windows 執行階段Windows Runtime structure, it provides the default behavior for value types that don't override Equals. 這是 .NET Framework 為 Windows 執行階段Windows Runtime 提供的支援之一部分(請參閱Windows Store 應用程式的 .NET Framework 支援和 Windows 執行階段)。This is part of the support that the .NET Framework provides for the Windows 執行階段Windows Runtime (see .NET Framework Support for Windows Store Apps and Windows Runtime). Windows 執行階段Windows Runtime 結構不能覆寫 Equals,即使它們是以C#或 Visual Basic 撰寫,因為它們不能有方法。structures can't override Equals, even if they're written with C# or Visual Basic, because they can't have methods. (此外,Windows 執行階段Windows Runtime 本身的結構不會繼承 ValueType)。不過,當您在或 Visual Basic 程式C#代碼中使用這些方法時,它們似乎會有 ToStringEqualsGetHashCode 方法,而且 .NET Framework 會提供這些方法的預設行為。(In addition, structures in the Windows 執行階段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.