UriTemplateEquivalenceComparer Class

Definition

Namespace:

System

Assembly:

System.ServiceModel.dll

A class used to compare UriTemplate instances for structural (instead of reference) equivalence.

public ref class UriTemplateEquivalenceComparer : System::Collections::Generic::IEqualityComparer<UriTemplate ^>

public class UriTemplateEquivalenceComparer : System.Collections.Generic.IEqualityComparer<UriTemplate>

type UriTemplateEquivalenceComparer = class
    interface IEqualityComparer<UriTemplate>

Public Class UriTemplateEquivalenceComparer
Implements IEqualityComparer(Of UriTemplate)

Inheritance

Object

UriTemplateEquivalenceComparer

Implements

IEqualityComparer<UriTemplate>

Examples

The following example shows the difference between reference equality and structural equality. It also shows how to use the UriTemplateEquivalenceComparer as a comparer in a dictionary.

// Define two structurally equivalent templates
UriTemplate temp1 = new UriTemplate("weather/{state}/{city}");
UriTemplate temp2 = new UriTemplate("weather/{country}/{village}");

// Notice they are not reference equal, in other words
// they are do not refer to the same object
if (temp1 == temp2)
    Console.WriteLine("{0} and {1} are reference equal", temp1, temp2);
else
    Console.WriteLine("{0} and {1} are NOT reference equal", temp1, temp2);

// Notice they are structrually equal
if (temp1.IsEquivalentTo(temp2))
    Console.WriteLine("{0} and {1} are structurally equal", temp1, temp2);
else
    Console.WriteLine("{0} and {1} are NOT structurally equal", temp1, temp2);

// Create a dictionary and use UriTemplateEquivalenceComparer as the comparer
Dictionary<UriTemplate, object> templates = new Dictionary<UriTemplate, object>(new UriTemplateEquivalenceComparer());

// Add template 1 into the dictionary
templates.Add(temp1, "template1");

// The UriTemplateEquivalenceComparer will be used here to compare the template in the table with template2
// they are structurally equivalent, so ContainsKey will return true.
if (templates.ContainsKey(temp2))
    Console.WriteLine("Both templates hash to the same value");
else
    Console.WriteLine("Both templates do NOT hash to the same value");

'Define two structurally equivalent templates
Dim temp1 As UriTemplate = New UriTemplate("weather/{state}/{city}")
Dim temp2 As UriTemplate = New UriTemplate("weather/{country}/{village}")

'Notice they are not reference equal, in other words
'they are do not refer to the same object
If temp1.Equals(temp2) Then
    Console.WriteLine("{0} and {1} are reference equal", temp1, temp2)
Else
    Console.WriteLine("{0} and {1} are NOT reference equal", temp1, temp2)
End If

'Notice they are structrually equal
If (temp1.IsEquivalentTo(temp2)) Then
    Console.WriteLine("{0} and {1} are structurally equal", temp1, temp2)
Else
    Console.WriteLine("{0} and {1} are NOT structurally equal", temp1, temp2)
End If

'Create a dictionary and use UriTemplateEquivalenceComparer as the comparer
Dim templates As Dictionary(Of UriTemplate, Object) = New Dictionary(Of UriTemplate, Object)(New UriTemplateEquivalenceComparer())

'Add template 1 into the dictionary
templates.Add(temp1, "template1")

'The UriTemplateEquivalenceComparer will be used here to compare the template in the table with template2
'they are structurally equivalent, so ContainsKey will return true.
If (templates.ContainsKey(temp2)) Then
    Console.WriteLine("Both templates hash to the same value")
Else
    Console.WriteLine("Both templates do NOT hash to the same value")
End If

Remarks

UriTemplate instances are compared using reference equality by default. The UriTemplateEquivalenceComparer class evaluates equivalence using IsEquivalentTo(UriTemplate) instead of the default reference equality check. This class is useful when you wish to compare two UriTemplate instances based on the URIs they match instead of strict reference equality.

Constructors

UriTemplateEquivalenceComparer()

Initializes a new instance of the UriTemplateEquivalenceComparer class.

Methods

Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
Equals(UriTemplate, UriTemplate)	Compares two UriTemplate instances for equivalence.
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetHashCode(UriTemplate)	Gets a hash code for the specified UriTemplate instance.
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)