MongoQueryableFirstAsyncTSource Method (IMongoQueryableTSource, ExpressionFuncTSource, Boolean, CancellationToken) |
Returns the first element of a sequence that satisfies a specified condition.
Namespace:
MongoDB.Driver.Linq
Assembly:
MongoDB.Driver (in MongoDB.Driver.dll) Version: 2.15.0+f503bf610759c13f78cff9a3c01e91453185d2ed
Syntax public static Task<TSource> FirstAsync<TSource>(
this IMongoQueryable<TSource> source,
Expression<Func<TSource, bool>> predicate,
CancellationToken cancellationToken = default
)
<ExtensionAttribute>
Public Shared Function FirstAsync(Of TSource) (
source As IMongoQueryable(Of TSource),
predicate As Expression(Of Func(Of TSource, Boolean)),
Optional cancellationToken As CancellationToken = Nothing
) As Task(Of TSource)
[<ExtensionAttribute>]
static member FirstAsync :
source : IMongoQueryable<'TSource> *
predicate : Expression<Func<'TSource, bool>> *
?cancellationToken : CancellationToken
(* Defaults:
let _cancellationToken = defaultArg cancellationToken new CancellationToken()
*)
-> Task<'TSource>
Parameters
- source
- Type: MongoDB.Driver.LinqIMongoQueryableTSource
An IMongoQueryableT to return an element from. - predicate
- Type: System.Linq.ExpressionsExpressionFuncTSource, Boolean
A function to test each element for a condition. - cancellationToken (Optional)
- Type: System.ThreadingCancellationToken
The cancellation token.
Type Parameters
- TSource
- The type of the elements of source.
Return Value
Type:
TaskTSource
The first element in
source that passes the test in
predicate.
Usage Note
In Visual Basic and C#, you can call this method as an instance method on any object of type
IMongoQueryableTSource. When you use instance method syntax to call this method, omit the first parameter. For more information, see
Extension Methods (Visual Basic) or
Extension Methods (C# Programming Guide).
See Also