How to page results from TFS WorkItemTrackingHttpClient QueryByWiqlAsync - tfs

Question

I'm using WorkItemTrackingHttpClient.QueryByWiqlAsync to retrieve the results of a query. It returns the top 200 records by default. It has a top param which you can use to specify a value less then 200.
However, the result of my query is greater than 200 records. Does anyone know how to execute a query using the TFS client with proper paging .i.e. page and page size? For example, return page 10 where the page count is say 50.
I've looked around but can't see how to do this using the client which is surprising as the capability seems so fundamental.
I'm using the Nuget Package Microsoft.TeamFoundationServer.Client 16.153.0. I'm also connecting to TFS 2017 onprem.

Answer 1

Yeah, we can only return a list of work items which limits to Maximum 200 by calling the API. It's by design, see Work Items - List for details.
However we can use WIQL Queries to retrieve data from Azure DevOps. It is very flexible and it could be used in any situation. See WIQL queries and Azure DevOps Rest API for WIQL Queries
To get all the work items, we can try following steps:
Execute a stored query using the work item query API to retrieve a
list of work item IDs
Split the list of work item IDs into groups of 200, which is the
maximum batch size that the work items API supports
Call the work items API for each list of 200 work item IDs to get
the work item details.
You can reference this thread for details.
Besides, below code for your reference, it's working for me:
using Microsoft.TeamFoundation.WorkItemTracking.WebApi;
using Microsoft.TeamFoundation.WorkItemTracking.WebApi.Models;
using Microsoft.VisualStudio.Services.Client;
using Microsoft.VisualStudio.Services.Common;
using System;
using System.Collections.Generic;
using System.Linq;
namespace QueryWorkitems0619
{
class Program
{
static void Main(string[] args)
{
Uri uri = new Uri("http://tfs2017:8080/tfs/DefaultCollection");
//string PAT = "xxxx";
string project = "SCRUM-TFVC";
//VssBasicCredential credentials = new VssBasicCredential(user, PAT);
VssCredentials credentials = new VssClientCredentials();
credentials.Storage = new VssClientCredentialStorage();
//create a wiql object and build our query
Wiql wiql = new Wiql()
{
Query = "Select * " +
"From WorkItems " +
"Where [Work Item Type] = 'Product Backlog Item' " +
"And [System.TeamProject] = '" + project + "' " +
"And [System.State] <> 'Closed' " +
"Order By [State] Asc, [Changed Date] Desc"
};
//create instance of work item tracking http client
using (WorkItemTrackingHttpClient workItemTrackingHttpClient = new WorkItemTrackingHttpClient(uri, credentials))
{
//execute the query to get the list of work items in the results
WorkItemQueryResult workItemQueryResult = workItemTrackingHttpClient.QueryByWiqlAsync(wiql).Result;
//Splict the query result (the list of work item IDs) into groups of 200.
var QueryGroups = from i in Enumerable.Range(0, workItemQueryResult.WorkItems.Count())
group workItemQueryResult.WorkItems.ToList()[i] by i / 200;
foreach (var QueryGroup in QueryGroups)
{
//some error handling
if (QueryGroup.Count() != 0)
{
//need to get the list of our work item ids and put them into an array
List<int> list = new List<int>();
foreach (var item in QueryGroup.ToList())
{
list.Add(item.Id);
}
int[] arr = list.ToArray();
//build a list of the fields we want to see
string[] fields = new string[3];
fields[0] = "System.Id";
fields[1] = "System.Title";
fields[2] = "System.State";
//get work items for the ids found in query
var workItems = workItemTrackingHttpClient.GetWorkItemsAsync(arr, fields, workItemQueryResult.AsOf).Result;
Console.WriteLine("\n\n----------------------------------------------------------------");
Console.WriteLine("\nQuery Results: {0} items found for Group {1}", workItems.Count, QueryGroup.Key);
Console.WriteLine("\n----------------------------------------------------------------");
//loop though work items and write to console
foreach (var workItem in workItems)
{
Console.WriteLine("ID:{0} Title:{1} State:{2}", workItem.Id, workItem.Fields["System.Title"], workItem.Fields["System.State"]);
}
}
}
Console.ReadLine();
}
}
}
}