Tuple<T1, T2, T3, T4, T5>.IStructuralEquatable.Equals Method
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Returns a value that indicates whether the current Tuple<T1, T2, T3, T4, T5> object is equal to a specified object based on a specified comparison method.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Private Function Equals ( _
other As Object, _
comparer As IEqualityComparer _
) As Boolean Implements IStructuralEquatable.Equals
bool IStructuralEquatable.Equals(
Object other,
IEqualityComparer comparer
)
Parameters
- other
Type: System.Object
The object to compare with this instance.
- comparer
Type: System.Collections.IEqualityComparer
An object that defines the method to use to evaluate whether the two objects are equal.
Return Value
Type: System.Boolean
true if the current instance is equal to the specified object; otherwise, false.
Implements
Remarks
This member is an explicit interface member implementation. It can be used only when the Tuple<T1, T2, T3, T4, T5> instance is cast to an IStructuralEquatable interface.
The IEqualityComparer.Equals implementation is called only if other is not nulla null reference (Nothing in Visual Basic), and if it can be successfully cast (in C#) or converted (in Visual Basic) to a Tuple<T1, T2, T3, T4, T5> object whose components are of the same types as the current instance. The IStructuralEquatable.Equals(Object, IEqualityComparer) method first passes the Item1 values of the Tuple<T1, T2, T3, T4, T5> objects to be compared to the IEqualityComparer.Equals implementation. If this method call returns true, the method is called again and passed the Item2 values of the two Tuple<T1, T2, T3, T4, T5> objects. This continues until the method call returns false when it compares a specific pair of Item values, or the two Item5 values are passed to the method.
Examples
The following example defines a DoubleComparer class that implements the IEqualityComparer interface. The example instantiates two Tuple<T1, T2, T3, T4, T5> objects by using a random number generator to populate their second through fifth components, casts the first instance to an IStructuralEquatable interface, and then uses a DoubleComparer object to test the two Tuple<T1, T2, T3, T4, T5> objects for approximate equality.
Imports System.Collections
Public Class DoubleComparer(Of T1, T2, T3, T4, T5) : Implements IEqualityComparer
Private difference As Double
Private argument As Integer = 0
Public Sub New(ByVal difference As Double)
Me.difference = difference
End Sub
Public Overloads Function Equals(ByVal x As Object, ByVal y As Object) As Boolean _
Implements IEqualityComparer.Equals
argument += 1
' Return true for Item1.
If argument = 1 Then
Return True
Else
Dim d1 As Double = CDbl(x)
Dim d2 As Double = CDbl(y)
If d1 - d2 < d1 * difference Then
Return True
Else
Return False
End If
End If
End Function
Public Overloads Function GetHashCode(ByVal 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()
ElseIf TypeOf obj Is T4 Then
Return CType(obj, T4).GetHashCode()
Else
Return CType(obj, T5).GetHashCode()
End If
End Function
End Class
Module Example
Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
Dim value1 = GetValues(1)
Dim value2 = GetValues(2)
Dim iValue1 As IStructuralEquatable = value1
outputBlock.Text += String.Format("{0} ={3}{1} :{3}{2}", value1, value2, _
iValue1.Equals(value2, _
New DoubleComparer(Of Integer, Double, Double, Double, Double)(0.01)), _
vbCrLf) & vbCrLf
End Sub
Private Function GetValues(ByVal ctr As Integer) As Tuple(Of Integer, Double, Double, Double, Double)
' Generate four random numbers between 0 and 1
Dim rnd As New Random(CInt((DateTime.Now.Ticks >> 32) >> ctr))
Return Tuple.Create(ctr, rnd.NextDouble(), rnd.NextDouble(), _
rnd.NextDouble(), rnd.NextDouble)
End Function
End Module
' The example displays output like the following:
' (1, 0.910850029862882, 0.894596965934428, 0.319678635019659, 0.801647342649124) =
' (2, 0.818546649915421, 0.355961162762698, 0.0438506622071614, 0.679904267042831) :
' False
using System;
using System.Collections;
public class DoubleComparer<T1, T2, T3, T4, T5> : IEqualityComparer
{
private double difference;
private int argument = 0;
public DoubleComparer(double difference)
{
this.difference = difference;
}
new public bool Equals(object x, object y)
{
argument += 1;
// Return true for Item1.
if (argument == 1) return true;
double d1 = (double)x;
double d2 = (double)y;
if (d1 - d2 < d1 * difference)
return true;
else
return false;
}
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 if (obj is T4)
return ((T4)obj).GetHashCode();
else
return ((T5)obj).GetHashCode();
}
}
public class Example
{
public static void Demo(System.Windows.Controls.TextBlock outputBlock)
{
var value1 = GetValues(1);
var value2 = GetValues(2);
IStructuralEquatable iValue1 = value1;
outputBlock.Text += String.Format("{0} =\n{1} :\n{2}", value1, value2,
iValue1.Equals(value2,
new DoubleComparer<int, double, double, double, double>(.01))) + "\n";
}
private static Tuple<int, double, double, double, double> GetValues(int ctr)
{
// Generate four random numbers between 0 and 1
Random rnd = new Random((int)DateTime.Now.Ticks >> 32 >> ctr);
return Tuple.Create(ctr, rnd.NextDouble(), rnd.NextDouble(),
rnd.NextDouble(), rnd.NextDouble());
}
}
Version Information
Silverlight
Supported in: 5, 4
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.