,System.Func{--0,--1})} ,System.Func{--0,--1},System.Collections.Generic.IEqualityComparer{--1})}

ObservableAsync.DistinctBy(IObservableAsync, Func) method¶

Defined in

Type: ObservableAsync Namespace: ReactiveUI.Extensions.Async Assembly: ReactiveUI.Extensions.dll

Applies to

net10.0, net10.0-browserwasm1.0, net10.0-desktop1.0, net9.0, net9.0-browserwasm1.0, net9.0-desktop1.0, net8.0, net8.0-ios17.5, net8.0-maccatalyst17.5, net8.0-macos14.2, net8.0-macos14.5, net8.0-tvos17.2, netstandard2.1, net462, net481

Overloads¶

1. public static IObservableAsync<T> DistinctBy<T, TKey>(this IObservableAsync<T> @this, Func<T, TKey> keySelector)
2. public static IObservableAsync<T> DistinctBy<T, TKey>(this IObservableAsync<T> @this, Func<T, TKey> keySelector, IEqualityComparer<TKey> equalityComparer)

1. Overload¶

public static IObservableAsync<T> DistinctBy<T, TKey>(this IObservableAsync<T> @this, Func<T, TKey> keySelector)

View source

Summary: Returns a sequence that contains distinct elements from the source sequence according to a specified key selector function.

Type parameters

Name	Description
`T`	The type of the elements in the source sequence.
`TKey`	The type of the key returned by the key selector function.

Parameters

Name	Type	Description
`this`	[IObservableAsync](#	The source observable sequence.
`keySelector`	Func	A function to extract the key for each element. Cannot be null.

Returns: IObservableAsync -- An observable sequence that contains only the first occurrence of each distinct key as determined by the key selector.

Remarks

Elements are considered distinct based on the value returned by the key selector and the default equality comparer for the key type.

2. Overload¶

public static IObservableAsync<T> DistinctBy<T, TKey>(this IObservableAsync<T> @this, Func<T, TKey> keySelector, IEqualityComparer<TKey> equalityComparer)

View source

Summary: Returns an observable sequence that contains only distinct elements from the source sequence, comparing values based on a specified key and equality comparer.

Type parameters

Name	Description
`T`	The type of the elements in the source sequence.
`TKey`	The type of the key used to determine the distinctness of elements.

Parameters

Name	Type	Description
`this`	[IObservableAsync](#	The source observable sequence.
`keySelector`	Func	A function to extract the key for each element. Cannot be null.
`equalityComparer`	IEqualityComparer	An equality comparer to compare keys for equality. Cannot be null.

Returns: IObservableAsync -- An observable sequence that contains only the first occurrence of each distinct key as determined by the specified key selector and equality comparer.

Remarks

Elements are considered distinct based on the value returned by the keySelector function and compared using the provided equalityComparer. Only the first occurrence of each key is included in the resulting sequence.

Exceptions

Type	Condition
System.ArgumentNullException	Thrown if `keySelector` or `equalityComparer` is null.