QueryResponse<T>.MoveNextAsync(QueryOptions, CancellationToken) Method

Reference

Definition

Namespace:: Microsoft.Azure.Devices

Assembly:: Microsoft.Azure.Devices.dll

Package:: Microsoft.Azure.Devices v2.0.0-preview002

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Advances to the next element of the query results.

public System.Threading.Tasks.Task<bool> MoveNextAsync (Microsoft.Azure.Devices.QueryOptions queryOptions = default, System.Threading.CancellationToken cancellationToken = default);

member this.MoveNextAsync : Microsoft.Azure.Devices.QueryOptions * System.Threading.CancellationToken -> System.Threading.Tasks.Task<bool>

Public Function MoveNextAsync (Optional queryOptions As QueryOptions = Nothing, Optional cancellationToken As CancellationToken = Nothing) As Task(Of Boolean)

Parameters

queryOptions: QueryOptions

cancellationToken: CancellationToken

Returns

Task<Boolean>

True if there was a next item in the query results. False if there were no more items.

Exceptions

IotHubServiceException

If this method made a request to IoT hub to get the next page of items but IoT hub responded to the request with a non-successful status code. For example, if the provided request was throttled, IotHubServiceException with ThrottlingException is thrown. For a complete list of possible error cases, see IotHubServiceErrorCode.

HttpRequestException

If this method made a request to IoT hub to get the next page of items but the HTTP request fails due to an underlying issue such as network connectivity, DNS failure, or server certificate validation.

OperationCanceledException

If the provided cancellation token has requested cancellation.

Examples


   QueryResponse<Twin> queriedTwins = await iotHubServiceClient.Query.CreateAsync<Twin>("SELECT * FROM devices");
   while (await queriedTwins.MoveNextAsync())
   {
       Twin queriedTwin = queriedTwins.Current;
       Console.WriteLine(queriedTwin);
   }

Remarks

Like with a more typical implementation of IEnumerator, this function should be called once before checking Current.

This function is async because it may make a service request to fetch the next page of results if the current page of results has been advanced through already. Note that this function will return True even if it is at the end of a particular page of items as long as there is at least one more page to be fetched.

Applies to

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