Returning the results from a series of Tasks run in Batches using C# and .Net (dotnet)

This article will review a straightforward way to return all the results from several Tasks which are run in batches. Batching your tasks will help manage resources on your servers so it is always a clever idea.

In your project, first install the batching NuGet package morelinq.

dotnet add package morelinq --version 4.1.0

With this package Batching is made much easier.

In our example I’ll be using a custom Cat object

class Cat

  {

    public string Name { get; set; }

    public string Breed { get; set; }

  }

We first create several tasks:

// Create a list of tasks that return Cat objects
List<Task<Cat>> tasks = new List<Task<Cat>>()
  {
  Task.Run(() => GetCat("Task 1")),
  Task.Run(() => GetCat("Task 2")),
  Task.Run(() => GetCat("Task 3"))
....and so on
  };

Then we batch the calls, 5 at a time:

int batchSize=5;
foreach (var batch in tasks.Batch(batchSize)) 
  await Task.WhenAll(batch.ToArray());

Next, we can pull all the Cat results out of the completed tasks:

// Retrieve the Cat objects from each task

 List<Cat> cats = tasks.Select(task => task.Result).ToList();

Done!