EntityFrameworkQueryableExtensions.ToDictionaryAsync Method

Definition

Overloads

ToDictionaryAsync<TSource,TKey,TElement>(IQueryable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, CancellationToken)

Creates a Dictionary<TKey,TValue> from an IQueryable<T> by enumerating it asynchronously according to a specified key selector and an element selector function.

ToDictionaryAsync<TSource,TKey,TElement>(IQueryable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>, CancellationToken)

Creates a Dictionary<TKey,TValue> from an IQueryable<T> by enumerating it asynchronously according to a specified key selector function, a comparer, and an element selector function.

ToDictionaryAsync<TSource,TKey>(IQueryable<TSource>, Func<TSource,TKey>, CancellationToken)

Creates a Dictionary<TKey,TValue> from an IQueryable<T> by enumerating it asynchronously according to a specified key selector function.

ToDictionaryAsync<TSource,TKey>(IQueryable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>, CancellationToken)

Creates a Dictionary<TKey,TValue> from an IQueryable<T> by enumerating it asynchronously according to a specified key selector function and a comparer.

ToDictionaryAsync<TSource,TKey,TElement>(IQueryable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, CancellationToken)

Creates a Dictionary<TKey,TValue> from an IQueryable<T> by enumerating it asynchronously according to a specified key selector and an element selector function.

public static System.Threading.Tasks.Task<System.Collections.Generic.Dictionary<TKey,TElement>> ToDictionaryAsync<TSource,TKey,TElement> (this System.Linq.IQueryable<TSource> source, Func<TSource,TKey> keySelector, Func<TSource,TElement> elementSelector, System.Threading.CancellationToken cancellationToken = default);
static member ToDictionaryAsync : System.Linq.IQueryable<'Source> * Func<'Source, 'Key> * Func<'Source, 'Element> * System.Threading.CancellationToken -> System.Threading.Tasks.Task<System.Collections.Generic.Dictionary<'Key, 'Element>>
<Extension()>
Public Function ToDictionaryAsync(Of TSource, TKey, TElement) (source As IQueryable(Of TSource), keySelector As Func(Of TSource, TKey), elementSelector As Func(Of TSource, TElement), Optional cancellationToken As CancellationToken = Nothing) As Task(Of Dictionary(Of TKey, TElement))

Type Parameters

TSource

The type of the elements of source.

TKey

The type of the key returned by keySelector.

TElement

The type of the value returned by elementSelector.

Parameters

source
IQueryable<TSource>

An IQueryable<T> to create a Dictionary<TKey,TValue> from.

keySelector
Func<TSource,TKey>

A function to extract a key from each element.

elementSelector
Func<TSource,TElement>

A transform function to produce a result element value from each element.

cancellationToken
CancellationToken

A CancellationToken to observe while waiting for the task to complete.

Returns

Task<Dictionary<TKey,TElement>>

A task that represents the asynchronous operation. The task result contains a Dictionary<TKey,TValue> that contains values of type TElement selected from the input sequence.

Exceptions

source or keySelector or elementSelector is null.

Remarks

Multiple active operations on the same context instance are not supported. Use await to ensure that any asynchronous operations have completed before calling another method on this context. See Avoiding DbContext threading issues for more information.

See Querying data with EF Core for more information.

Applies to

ToDictionaryAsync<TSource,TKey,TElement>(IQueryable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>, CancellationToken)

Creates a Dictionary<TKey,TValue> from an IQueryable<T> by enumerating it asynchronously according to a specified key selector function, a comparer, and an element selector function.

public static System.Threading.Tasks.Task<System.Collections.Generic.Dictionary<TKey,TElement>> ToDictionaryAsync<TSource,TKey,TElement> (this System.Linq.IQueryable<TSource> source, Func<TSource,TKey> keySelector, Func<TSource,TElement> elementSelector, System.Collections.Generic.IEqualityComparer<TKey> comparer, System.Threading.CancellationToken cancellationToken = default);
public static System.Threading.Tasks.Task<System.Collections.Generic.Dictionary<TKey,TElement>> ToDictionaryAsync<TSource,TKey,TElement> (this System.Linq.IQueryable<TSource> source, Func<TSource,TKey> keySelector, Func<TSource,TElement> elementSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer, System.Threading.CancellationToken cancellationToken = default);
static member ToDictionaryAsync : System.Linq.IQueryable<'Source> * Func<'Source, 'Key> * Func<'Source, 'Element> * System.Collections.Generic.IEqualityComparer<'Key> * System.Threading.CancellationToken -> System.Threading.Tasks.Task<System.Collections.Generic.Dictionary<'Key, 'Element>>
<Extension()>
Public Function ToDictionaryAsync(Of TSource, TKey, TElement) (source As IQueryable(Of TSource), keySelector As Func(Of TSource, TKey), elementSelector As Func(Of TSource, TElement), comparer As IEqualityComparer(Of TKey), Optional cancellationToken As CancellationToken = Nothing) As Task(Of Dictionary(Of TKey, TElement))

Type Parameters

TSource

The type of the elements of source.

TKey

The type of the key returned by keySelector.

TElement

The type of the value returned by elementSelector.

Parameters

source
IQueryable<TSource>

An IQueryable<T> to create a Dictionary<TKey,TValue> from.

keySelector
Func<TSource,TKey>

A function to extract a key from each element.

elementSelector
Func<TSource,TElement>

A transform function to produce a result element value from each element.

comparer
IEqualityComparer<TKey>

An IEqualityComparer<T> to compare keys.

cancellationToken
CancellationToken

A CancellationToken to observe while waiting for the task to complete.

Returns

Task<Dictionary<TKey,TElement>>

A task that represents the asynchronous operation. The task result contains a Dictionary<TKey,TValue> that contains values of type TElement selected from the input sequence.

Exceptions

source or keySelector or elementSelector is null.

Remarks

Multiple active operations on the same context instance are not supported. Use await to ensure that any asynchronous operations have completed before calling another method on this context. See Avoiding DbContext threading issues for more information.

See Querying data with EF Core for more information.

Applies to

ToDictionaryAsync<TSource,TKey>(IQueryable<TSource>, Func<TSource,TKey>, CancellationToken)

Creates a Dictionary<TKey,TValue> from an IQueryable<T> by enumerating it asynchronously according to a specified key selector function.

public static System.Threading.Tasks.Task<System.Collections.Generic.Dictionary<TKey,TSource>> ToDictionaryAsync<TSource,TKey> (this System.Linq.IQueryable<TSource> source, Func<TSource,TKey> keySelector, System.Threading.CancellationToken cancellationToken = default);
static member ToDictionaryAsync : System.Linq.IQueryable<'Source> * Func<'Source, 'Key> * System.Threading.CancellationToken -> System.Threading.Tasks.Task<System.Collections.Generic.Dictionary<'Key, 'Source>>
<Extension()>
Public Function ToDictionaryAsync(Of TSource, TKey) (source As IQueryable(Of TSource), keySelector As Func(Of TSource, TKey), Optional cancellationToken As CancellationToken = Nothing) As Task(Of Dictionary(Of TKey, TSource))

Type Parameters

TSource

The type of the elements of source.

TKey

The type of the key returned by keySelector.

Parameters

source
IQueryable<TSource>

An IQueryable<T> to create a Dictionary<TKey,TValue> from.

keySelector
Func<TSource,TKey>

A function to extract a key from each element.

cancellationToken
CancellationToken

A CancellationToken to observe while waiting for the task to complete.

Returns

Task<Dictionary<TKey,TSource>>

A task that represents the asynchronous operation. The task result contains a Dictionary<TKey,TValue> that contains selected keys and values.

Exceptions

source or keySelector is null.

Remarks

Multiple active operations on the same context instance are not supported. Use await to ensure that any asynchronous operations have completed before calling another method on this context. See Avoiding DbContext threading issues for more information.

See Querying data with EF Core for more information.

Applies to

ToDictionaryAsync<TSource,TKey>(IQueryable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>, CancellationToken)

Creates a Dictionary<TKey,TValue> from an IQueryable<T> by enumerating it asynchronously according to a specified key selector function and a comparer.

public static System.Threading.Tasks.Task<System.Collections.Generic.Dictionary<TKey,TSource>> ToDictionaryAsync<TSource,TKey> (this System.Linq.IQueryable<TSource> source, Func<TSource,TKey> keySelector, System.Collections.Generic.IEqualityComparer<TKey> comparer, System.Threading.CancellationToken cancellationToken = default);
static member ToDictionaryAsync : System.Linq.IQueryable<'Source> * Func<'Source, 'Key> * System.Collections.Generic.IEqualityComparer<'Key> * System.Threading.CancellationToken -> System.Threading.Tasks.Task<System.Collections.Generic.Dictionary<'Key, 'Source>>
<Extension()>
Public Function ToDictionaryAsync(Of TSource, TKey) (source As IQueryable(Of TSource), keySelector As Func(Of TSource, TKey), comparer As IEqualityComparer(Of TKey), Optional cancellationToken As CancellationToken = Nothing) As Task(Of Dictionary(Of TKey, TSource))

Type Parameters

TSource

The type of the elements of source.

TKey

The type of the key returned by keySelector.

Parameters

source
IQueryable<TSource>

An IQueryable<T> to create a Dictionary<TKey,TValue> from.

keySelector
Func<TSource,TKey>

A function to extract a key from each element.

comparer
IEqualityComparer<TKey>

An IEqualityComparer<T> to compare keys.

cancellationToken
CancellationToken

A CancellationToken to observe while waiting for the task to complete.

Returns

Task<Dictionary<TKey,TSource>>

A task that represents the asynchronous operation. The task result contains a Dictionary<TKey,TValue> that contains selected keys and values.

Exceptions

source or keySelector is null.

Remarks

Multiple active operations on the same context instance are not supported. Use await to ensure that any asynchronous operations have completed before calling another method on this context. See Avoiding DbContext threading issues for more information.

See Querying data with EF Core for more information.

Applies to