Tuple<T1,T2,T3,T4,T5,T6>.IStructuralEquatable.Equals 方法

参考

定义

命名空间:: System

程序集:: System.Runtime.dll

程序集:: mscorlib.dll

程序集:: netstandard.dll

重要

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返回一个值，该值根据指定的比较方法指示当前的 Tuple<T1,T2,T3,T4,T5,T6> 对象是否与指定对象相等。

 virtual bool System.Collections.IStructuralEquatable.Equals(System::Object ^ other, System::Collections::IEqualityComparer ^ comparer) = System::Collections::IStructuralEquatable::Equals;

bool IStructuralEquatable.Equals (object other, System.Collections.IEqualityComparer comparer);

abstract member System.Collections.IStructuralEquatable.Equals : obj * System.Collections.IEqualityComparer -> bool
override this.System.Collections.IStructuralEquatable.Equals : obj * System.Collections.IEqualityComparer -> bool

Function Equals (other As Object, comparer As IEqualityComparer) As Boolean Implements IStructuralEquatable.Equals

参数

other: Object

与该实例进行比较的对象。

comparer: IEqualityComparer

一个对象，该对象定义用于评估两个对象是否相等的方法。

Boolean

如果当前实例等于指定对象，则为 true；否则为 false。

实现

Equals(Object, IEqualityComparer)

示例

以下示例定义一个 RateComparer 类，该类对相等性执行自定义测试。如果传递给其IStructuralEquatable.Equals方法的值的类型为Double或Single，则该方法仅使用最多三个小数位数来测试相等性。否则，它只需调用 x 参数 Equals 的方法。此示例使用此 IEqualityComparer 实现来确定包含 1960 年至 2000 年间总体变化速率的数据的四 Tuple<T1,T2,T3,T4,T5,T6> 个对象是否相等。

using System;
using System.Collections;

public class RateComparer<T1, T2, T3, T4, T5, T6> : IEqualityComparer
{
   private int argument = 0;

   public new bool Equals(object x, object y) 
   {
      argument++;
      if (argument == 1) return true;

      double fx, fy; 
      if (x is Double || x is Single)
      {
            fx = (double) x;
            fy = (double) y;
            return Math.Round(fx * 1000).Equals(Math.Round(fy * 1000));
      }
      else
      {
         return x.Equals(y);
      }
   }
   
   public int GetHashCode(object obj)
   {
      if (obj is Single || obj is Double)
         return Math.Round(((double) obj) * 1000).GetHashCode();
      else
         return obj.GetHashCode();
   }                
}

public class Example
{
   public static void Main()
   {
      var rate1 = Tuple.Create("New York", .014505, -.1042733, 
                               .0354833, .093644, .0290792);
      var rate2 = Tuple.Create("Unknown City", .014505, -.1042733, 
                               .0354833, .093644, .0290792);
      var rate3 = Tuple.Create("Unknown City", .014505, -.1042733, 
                               .0354833, .093644, .029079);
      var rate4 = Tuple.Create("San Francisco", -.0332858, -.0512803, 
                               .0662544, .0728964, .0491912);
      IStructuralEquatable eq = rate1;
      // Compare first tuple with remaining two tuples.
      Console.WriteLine("{0} = ", rate1.ToString());
      Console.WriteLine("   {0} : {1}", rate2, 
                        eq.Equals(rate2, new RateComparer<string, double, double, double, double, double>()));
      Console.WriteLine("   {0} : {1}", rate3, 
                        eq.Equals(rate3, new RateComparer<string, double, double, double, double, double>()));
      Console.WriteLine("   {0} : {1}", rate4, 
                        eq.Equals(rate4, new RateComparer<string, double, double, double, double, double>()));
   }
}
// The example displays the following output:
//    (New York, 0.014505, -0.1042733, 0.0354833, 0.093644, 0.0290792) =
//       (Unknown City, 0.014505, -0.1042733, 0.0354833, 0.093644, 0.0290792) : True
//       (Unknown City, 0.014505, -0.1042733, 0.0354833, 0.093644, 0.029079) : True
//       (San Francisco, -0.0332858, -0.0512803, 0.0662544, 0.0728964, 0.0491912) : False

open System
open System.Collections

type RateComparer<'T1, 'T2, 'T3, 'T4, 'T5, 'T6>() =
    let mutable argument = 0

    interface IEqualityComparer with
        member _.Equals(x, y) = 
            argument <- argument + 1
            if argument = 1 then true
            else
                match x with
                | :? double as fx ->
                    let fy = y :?> double
                    Math.Round(fx * 1000.).Equals(Math.Round(fy * 1000.))
                | _ ->
                    x.Equals y
        
        member _.GetHashCode(obj) =
            if obj :? Single || obj :? Double then
                Math.Round((obj :?> double) * 1000.).GetHashCode()
            else
                obj.GetHashCode()

let rate1 = Tuple.Create("New York", 0.014505, -0.1042733, 0.0354833, 0.093644, 0.0290792)
let rate2 = Tuple.Create("Unknown City", 0.014505, -0.1042733, 0.0354833, 0.093644, 0.0290792)
let rate3 = Tuple.Create("Unknown City", 0.014505, -0.1042733, 0.0354833, 0.093644, 0.029079)
let rate4 = Tuple.Create("San Francisco", -0.0332858, -0.0512803, 0.0662544, 0.0728964, 0.0491912)
let eq: IStructuralEquatable = rate1
// Compare first tuple with remaining two tuples.
printfn $"{rate1} = "
printfn $"   {rate2} : {eq.Equals(rate2, RateComparer<string, double, double, double, double, double>())}"
printfn $"   {rate3} : {eq.Equals(rate3, RateComparer<string, double, double, double, double, double>())}"
printfn $"   {rate4} : {eq.Equals(rate4, RateComparer<string, double, double, double, double, double>())}"
// The example displays the following output:
//    (New York, 0.014505, -0.1042733, 0.0354833, 0.093644, 0.0290792) =
//       (Unknown City, 0.014505, -0.1042733, 0.0354833, 0.093644, 0.0290792) : True
//       (Unknown City, 0.014505, -0.1042733, 0.0354833, 0.093644, 0.029079) : True
//       (San Francisco, -0.0332858, -0.0512803, 0.0662544, 0.0728964, 0.0491912) : False

Imports System.Collections

Public Class RateComparer(Of T1, T2, T3, T4, T5, T6) : Implements IEqualityComparer
   Private argument As Integer = 0

   Public Overloads Function Equals(x As Object, y As Object) As Boolean _
                   Implements IEqualityComparer.Equals
      argument += 1
      If argument = 1 Then
         Return True
      Else
         Dim fx, fy As Double
         If typeof x Is Double Or typeof x Is Single Then
            fx = CDbl(x)
            fy = CDbl(y)
            Return Math.Round(fx * 1000).Equals(Math.Round(fy * 1000))
         Else
            Return x.Equals(y)
         End If
      End If   
   End Function
   
   Public Overloads Function GetHashCode(obj As Object) As Integer _
                    Implements IEqualityComparer.GetHashCode
      If TypeOf(obj) Is Single Or TypeOf(obj) Is Double Then
         Return Math.Round(CDbl(obj) * 1000).GetHashCode()
      Else
         Return obj.GetHashCode()
      End If
   End Function                
End Class

Module Example
   Public Sub Main()
      Dim rate1 = Tuple.Create("New York", .014505, -.1042733, 
                               .0354833, .093644, .0290792)
      Dim rate2 = Tuple.Create("Unknown City", .014505, -.1042733, 
                               .0354833, .093644, .0290792)
      Dim rate3 = Tuple.Create("Unknown City", .014505, -.1042733, 
                               .0354833, .093644, .029079)
      Dim rate4 = Tuple.Create("San Francisco", -.0332858, -.0512803, 
                               .0662544, .0728964, .0491912)
      Dim eq As IStructuralEquatable = rate1
      ' Compare first tuple with remaining two tuples.
      Console.WriteLine("{0} = ", rate1.ToString())
      Console.WriteLine("   {0} : {1}", rate2, 
                        eq.Equals(rate2, New RateComparer(Of String, Double, Double, Double, Double, Double)()))
      Console.WriteLine("   {0} : {1}", rate3, 
                        eq.Equals(rate3, New RateComparer(Of String, Double, Double, Double, Double, Double)()))
      Console.WriteLine("   {0} : {1}", rate4, 
                        eq.Equals(rate4, New RateComparer(Of String, Double, Double, Double, Double, Double)()))
   End Sub
End Module
' The example displays the following output:
'    (New York, 0.014505, -0.1042733, 0.0354833, 0.093644, 0.0290792) =
'       (Unknown City, 0.014505, -0.1042733, 0.0354833, 0.093644, 0.0290792) : True
'       (Unknown City, 0.014505, -0.1042733, 0.0354833, 0.093644, 0.029079) : True
'       (San Francisco, -0.0332858, -0.0512803, 0.0662544, 0.0728964, 0.0491912) : False

注解

此成员是显式接口成员的实现。它只能在 Tuple<T1,T2,T3,T4,T5,T6> 实例被强制转换为 IStructuralEquatable 接口时使用。

IEqualityComparer.Equals仅当other不是null时，才能调用该实现，如果可以在 C#) 中成功转换 (，或者Visual Basic) 中Tuple<T1,T2,T3,T4,T5,T6>转换为组件的类型与当前实例相同的对象 (。该方法IStructuralEquatable.Equals(Object, IEqualityComparer)首先传递Item1要与实现进行比较IEqualityComparer.Equals的对象的值Tuple<T1,T2,T3,T4,T5,T6>。如果此方法调用返回 true，则再次调用该方法并传递 Item2 两 Tuple<T1,T2,T3,T4,T5,T6> 个对象的值。这一点一直持续到方法调用在比较特定值对Item或两Item6个值传递给方法时返回false。

适用于

Tuple<T1,T2,T3,T4,T5,T6>.IStructuralEquatable.Equals 方法

定义

参数

返回

实现

示例

注解

适用于

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