Class JsonCollectionComparerAttribute
- Namespace
- Nerdbank.Json
- Assembly
- Nerdbank.Json.dll
Selects the IEqualityComparer<T> or IComparer<T> that the deserializer uses when it constructs the collection for the decorated dictionary or set member.
[AttributeUsage(AttributeTargets.Property|AttributeTargets.Field|AttributeTargets.Parameter, AllowMultiple = false, Inherited = false)]
[AssociatedTypeAttribute("comparerType", TypeShapeRequirements.Constructor)]
public sealed class JsonCollectionComparerAttribute : Attribute- Inheritance
-
JsonCollectionComparerAttribute
- Inherited Members
Examples
Remarks
The serializer already exposes a global ComparerProvider, but that provider cannot preserve member-specific semantics such as a case-insensitive dictionary. Apply this attribute to a property, field, or constructor parameter whose type is a mutable dictionary or set to control the comparer used for the freshly constructed collection during deserialization.
The comparer type must declare a public parameterless constructor and implement IEqualityComparer<T> or IComparer<T> for the collection's key or element type. It is activated through a source-generated type shape rather than runtime reflection, so the feature remains trimming-safe and NativeAOT-compatible. The comparer only influences the instances the deserializer creates; specify the same comparer in the member's initializer to influence instances that application code creates.
Getter-only collection initializers remain the preferred zero-configuration alternative: when a member is getter-only and already initialized with the desired comparer, the deserializer populates that instance and this attribute is unnecessary.
Constructors
JsonCollectionComparerAttribute(Type)
Initializes a new instance of the JsonCollectionComparerAttribute class.
public JsonCollectionComparerAttribute(Type comparerType)Parameters
comparerTypeTypeThe comparer type to activate. It must declare a public parameterless constructor and implement IEqualityComparer<T> or IComparer<T> for the decorated collection's key or element type.
Properties
ComparerType
Gets the comparer type activated for the decorated collection member.
public Type ComparerType { get; }