Tuple<T1,T2,T3,T4>.IStructuralEquatable.Equals Metode
Definisi
Penting
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Mengembalikan nilai yang menunjukkan apakah objek saat ini Tuple<T1,T2,T3,T4> sama dengan objek tertentu berdasarkan metode perbandingan yang ditentukan.
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 -> boolFunction Equals (other As Object, comparer As IEqualityComparer) As Boolean Implements IStructuralEquatable.EqualsParameter
- other
- Object
Objek untuk dibandingkan dengan instans ini.
- comparer
- IEqualityComparer
Objek yang menentukan metode yang akan digunakan untuk mengevaluasi apakah kedua objek sama.
Mengembalikan
true jika instans saat ini sama dengan objek yang ditentukan; jika tidak, false.
Penerapan
Contoh
Contoh berikut mendefinisikan Item3And4Comparer kelas yang mengimplementasikan IEqualityComparer antarmuka dan mengubah cara Tuple<T1,T2,T3,T4> objek dievaluasi untuk kesetaraan. Metode selalu mengembalikan ketika diteruskan Item1 nilai properti dan Item2 dari dua Tuple<T1,T2,T3,T4> objek, dan memanggil obj.Equals metode untuk mengevaluasi nilai properti merekaItem3.true Panggilan metode ini mengembalikan true, ini juga memanggil obj.Equals metode untuk mengevaluasi nilai properti tuples Item4 . Akibatnya, metode menguji kesetaraan hanya berdasarkan nilai Item3 properti dan Item4 . Output mengilustrasikan hasil untuk kumpulan Tuple<T1,T2,T3,T4> data objek yang mencatat nama kota AS, bulan dalam setahun, dan suhu tinggi dan rendah rata-rata untuk bulan tersebut.
using System;
using System.Collections;
public class Item3And4Comparer<T1, T2, T3, T4> : IEqualityComparer
{
private int argument = 0;
new public bool Equals(object x, object y)
{
argument++;
// Return true for all values of Item1, Item2.
if (argument <= 2)
return true;
else
return x.Equals(y);
}
public int GetHashCode(object obj)
{
if (obj is T1)
return ((T1) obj).GetHashCode();
else if (obj is T2)
return ((T2) obj).GetHashCode();
else if (obj is T3)
return ((T3) obj).GetHashCode();
else
return ((T4) obj).GetHashCode();
}
}
public class Example
{
public static void Main()
{
Tuple<string, int, double, double>[] temperatures =
{ Tuple.Create("New York, NY", 4, 61.0, 43.0),
Tuple.Create("Chicago, IL", 2, 34.0, 18.0),
Tuple.Create("Newark, NJ", 4, 61.0, 43.0),
Tuple.Create("Boston, MA", 6, 77.0, 59.0),
Tuple.Create("Detroit, MI", 9, 74.0, 53.0),
Tuple.Create("Minneapolis, MN", 8, 81.0, 61.0) };
// Compare each item with every other item for equality.
for (int ctr = 0; ctr < temperatures.Length; ctr++)
{
IStructuralEquatable temperatureInfo = temperatures[ctr];
for (int ctr2 = ctr + 1; ctr2 < temperatures.Length; ctr2++)
Console.WriteLine("{0} = {1}: {2}",
temperatureInfo, temperatures[ctr2],
temperatureInfo.Equals(temperatures[ctr2],
new Item3And4Comparer<string, int, double, double>()));
Console.WriteLine();
}
}
}
// The example displays the following output:
// (New York, NY, 4, 61, 43) = (Chicago, IL, 2, 34, 18): False
// (New York, NY, 4, 61, 43) = (Newark, NJ, 4, 61, 43): True
// (New York, NY, 4, 61, 43) = (Boston, MA, 6, 77, 59): False
// (New York, NY, 4, 61, 43) = (Detroit, MI, 9, 74, 53): False
// (New York, NY, 4, 61, 43) = (Minneapolis, MN, 8, 81, 61): False
//
// (Chicago, IL, 2, 34, 18) = (Newark, NJ, 4, 61, 43): False
// (Chicago, IL, 2, 34, 18) = (Boston, MA, 6, 77, 59): False
// (Chicago, IL, 2, 34, 18) = (Detroit, MI, 9, 74, 53): False
// (Chicago, IL, 2, 34, 18) = (Minneapolis, MN, 8, 81, 61): False
//
// (Newark, NJ, 4, 61, 43) = (Boston, MA, 6, 77, 59): False
// (Newark, NJ, 4, 61, 43) = (Detroit, MI, 9, 74, 53): False
// (Newark, NJ, 4, 61, 43) = (Minneapolis, MN, 8, 81, 61): False
//
// (Boston, MA, 6, 77, 59) = (Detroit, MI, 9, 74, 53): False
// (Boston, MA, 6, 77, 59) = (Minneapolis, MN, 8, 81, 61): False
//
// (Detroit, MI, 9, 74, 53) = (Minneapolis, MN, 8, 81, 61): False
open System
open System.Collections
type Item3And4Comparer<'T1, 'T2, 'T3, 'T4 when 'T1: equality and 'T2: equality and 'T3: equality and 'T4: equality>() =
let mutable argument = 0
interface IEqualityComparer with
member _.Equals(x: obj, y: obj) =
argument <- argument + 1
// Return true for all values of Item1, Item2.
if argument <= 2 then
true
else
x.Equals y
member _.GetHashCode(obj: obj) =
match obj with
| :? 'T1 as obj ->
obj.GetHashCode()
| :? 'T2 as obj ->
obj.GetHashCode()
| :? 'T3 as obj ->
obj.GetHashCode()
| _ ->
(obj :?> 'T4).GetHashCode()
let temperatures =
[| Tuple.Create("New York, NY", 4, 61.0, 43.0)
Tuple.Create("Chicago, IL", 2, 34.0, 18.0)
Tuple.Create("Newark, NJ", 4, 61.0, 43.0)
Tuple.Create("Boston, MA", 6, 77.0, 59.0)
Tuple.Create("Detroit, MI", 9, 74.0, 53.0)
Tuple.Create("Minneapolis, MN", 8, 81.0, 61.0) |]
// Compare each item with every other item for equality.
for ctr = 0 to temperatures.Length - 1 do
let temperatureInfo: IStructuralEquatable = temperatures[ctr]
for ctr2 = ctr + 1 to temperatures.Length - 1 do
printfn $"{temperatureInfo} = {temperatures[ctr2]}: {temperatureInfo.Equals(temperatures[ctr2], Item3And4Comparer<string, int, double, double>())}"
printfn ""
// The example displays the following output:
// (New York, NY, 4, 61, 43) = (Chicago, IL, 2, 34, 18): False
// (New York, NY, 4, 61, 43) = (Newark, NJ, 4, 61, 43): True
// (New York, NY, 4, 61, 43) = (Boston, MA, 6, 77, 59): False
// (New York, NY, 4, 61, 43) = (Detroit, MI, 9, 74, 53): False
// (New York, NY, 4, 61, 43) = (Minneapolis, MN, 8, 81, 61): False
//
// (Chicago, IL, 2, 34, 18) = (Newark, NJ, 4, 61, 43): False
// (Chicago, IL, 2, 34, 18) = (Boston, MA, 6, 77, 59): False
// (Chicago, IL, 2, 34, 18) = (Detroit, MI, 9, 74, 53): False
// (Chicago, IL, 2, 34, 18) = (Minneapolis, MN, 8, 81, 61): False
//
// (Newark, NJ, 4, 61, 43) = (Boston, MA, 6, 77, 59): False
// (Newark, NJ, 4, 61, 43) = (Detroit, MI, 9, 74, 53): False
// (Newark, NJ, 4, 61, 43) = (Minneapolis, MN, 8, 81, 61): False
//
// (Boston, MA, 6, 77, 59) = (Detroit, MI, 9, 74, 53): False
// (Boston, MA, 6, 77, 59) = (Minneapolis, MN, 8, 81, 61): False
//
// (Detroit, MI, 9, 74, 53) = (Minneapolis, MN, 8, 81, 61): False
Imports System.Collections
Public Class Item3And4Comparer(Of T1, T2, T3, T4) : Implements IEqualityComparer
Private argument As Integer = 0
Public Overloads Function Equals(x As Object, y As Object) As Boolean _
Implements IEqualityComparer.Equals
argument += 1
' Return true for all values of Item1, Item2.
If argument <= 2 Then
Return True
Else
Return x.Equals(y)
End If
End Function
Public Overloads Function GetHashCode(obj As Object) As Integer _
Implements IEqualityComparer.GetHashCode
If TypeOf obj Is T1 Then
Return CType(obj, T1).GetHashCode()
ElseIf TypeOf obj Is T2 Then
Return CType(obj, T2).GetHashCode()
ElseIf TypeOf obj Is T3 Then
REturn CType(Obj, T3).GetHashCode()
Else
Return CType(obj, T4).GetHashCode()
End If
End Function
End Class
Module Example
Public Sub Main()
Dim temperatures() =
{ Tuple.Create("New York, NY", 4, 61, 43), _
Tuple.Create("Chicago, IL", 2, 34, 18), _
Tuple.Create("Newark, NJ", 4, 61, 43), _
Tuple.Create("Boston, MA", 6, 77, 59), _
Tuple.Create("Detroit, MI", 9, 74, 53), _
Tuple.Create("Minneapolis, MN", 8, 81, 61) }
' Compare each item with every other item for equality.
For ctr As Integer = 0 To temperatures.Length - 1
Dim temperatureInfo As IStructuralEquatable = temperatures(ctr)
For ctr2 As Integer = ctr + 1 To temperatures.Length - 1
Console.WriteLine("{0} = {1}: {2}",
temperatureInfo, temperatures(ctr2),
temperatureInfo.Equals(temperatures(ctr2),
New Item3And4Comparer(Of String, Integer, Double, Double)))
Next
Console.WriteLine()
Next
End Sub
End Module
' The example displays the following output:
' (New York, NY, 4, 61, 43) = (Chicago, IL, 2, 34, 18): False
' (New York, NY, 4, 61, 43) = (Newark, NJ, 4, 61, 43): True
' (New York, NY, 4, 61, 43) = (Boston, MA, 6, 77, 59): False
' (New York, NY, 4, 61, 43) = (Detroit, MI, 9, 74, 53): False
' (New York, NY, 4, 61, 43) = (Minneapolis, MN, 8, 81, 61): False
'
' (Chicago, IL, 2, 34, 18) = (Newark, NJ, 4, 61, 43): False
' (Chicago, IL, 2, 34, 18) = (Boston, MA, 6, 77, 59): False
' (Chicago, IL, 2, 34, 18) = (Detroit, MI, 9, 74, 53): False
' (Chicago, IL, 2, 34, 18) = (Minneapolis, MN, 8, 81, 61): False
'
' (Newark, NJ, 4, 61, 43) = (Boston, MA, 6, 77, 59): False
' (Newark, NJ, 4, 61, 43) = (Detroit, MI, 9, 74, 53): False
' (Newark, NJ, 4, 61, 43) = (Minneapolis, MN, 8, 81, 61): False
'
' (Boston, MA, 6, 77, 59) = (Detroit, MI, 9, 74, 53): False
' (Boston, MA, 6, 77, 59) = (Minneapolis, MN, 8, 81, 61): False
'
' (Detroit, MI, 9, 74, 53) = (Minneapolis, MN, 8, 81, 61): False
Keterangan
Anggota ini adalah implementasi anggota antarmuka eksplisit. Ini hanya dapat digunakan ketika instans dilemparkan Tuple<T1,T2,T3,T4> ke IStructuralEquatable antarmuka.
Implementasi IEqualityComparer.Equals dipanggil hanya jika other bukan null, dan jika dapat berhasil ditransmisikan (dalam C#) atau dikonversi (di Visual Basic) ke Tuple<T1,T2,T3,T4> objek yang komponennya memiliki jenis yang sama dengan instans saat ini. Metode ini IStructuralEquatable.Equals(Object, IEqualityComparer) terlebih dahulu meneruskan Item1 nilai Tuple<T1,T2,T3,T4> objek yang akan dibandingkan IEqualityComparer.Equals dengan implementasi. Jika panggilan metode ini mengembalikan true, metode dipanggil lagi dan melewati Item2 nilai dua Tuple<T1,T2,T3,T4> objek. Jika panggilan metode ini kembali true , metode ini dipanggil untuk ketiga kalinya dan melewati Item3 nilai dua Tuple<T1,T2,T3,T4> objek. Jika panggilan metode ini kembali true lagi, metode dipanggil untuk waktu keempat dan terakhir dan melewati Item4 nilai dua Tuple<T1,T2,T3,T4> objek.
