XPQueryExtensions.ToLookupAsync<T, TKey>(IQueryable<T>, Func<T, TKey>, IEqualityComparer<TKey>, CancellationToken) Method
Asynchronously enumerates a query and uses a key selector and a comparer to construct a Lookup<TKey,TElement>.
Namespace: DevExpress.Xpo
Assembly: DevExpress.Xpo.v18.2.dll
Declaration
public static Task<ILookup<TKey, T>> ToLookupAsync<T, TKey>(
this IQueryable<T> query,
Func<T, TKey> keySelector,
IEqualityComparer<TKey> equalityComparer,
CancellationToken cancellationToken = default(CancellationToken)
)
Parameters
Name | Type | Description |
---|---|---|
query | IQueryable<T> | An XPQuery<T> to be enumerated. |
keySelector | Func<T, TKey> | A function that acquires each persistent object’s key. |
equalityComparer | IEqualityComparer<TKey> | A function that returns a result value for each persistent object. |
Optional Parameters
Name | Type | Default | Description |
---|---|---|---|
cancellationToken | CancellationToken | *null* | A CancellationToken object that delivers a cancellation notice to the running operation. |
Type Parameters
Name |
---|
T |
TKey |
Returns
Type | Description |
---|---|
Task<ILookup<TKey, T>> | A Task that returns a Lookup<TKey,TElement>. |
See Also