Task<TResult>.Factory Property

Definition

Namespace:

System.Threading.Tasks

Assemblies:

netstandard.dll, System.Runtime.dll

Source:

Future.cs

Gets a factory method for creating and configuring Task<TResult> instances.

C#

public static System.Threading.Tasks.TaskFactory<TResult> Factory { get; }

Property Value

TaskFactory<TResult>

A factory object that can create a variety of Task<TResult> objects.

Remarks

This property returns a default instance of the TaskFactory<TResult> class that is identical to the one created by calling the parameterless TaskFactory<TResult>.TaskFactory<TResult>() constructor. It has the following property values:

Property	Value
TaskFactory<TResult>.CancellationToken	CancellationToken.None
TaskFactory<TResult>.ContinuationOptions	TaskContinuationOptions.None
TaskFactory<TResult>.CreationOptions	TaskCreationOptions.None
TaskFactory<TResult>.Scheduler	null, or TaskScheduler.Current

The most common use of this property is to create and start a new task in a single call to the TaskFactory<TResult>.StartNew method.

Note

Starting with .NET Framework 4.5, the Task.Run method provides the easiest way to create a Task<TResult> object with default configuration values.

The following example uses the static Factory property to make three calls to the TaskFactory<TResult>.StartNew method. The first starts a Task<Int32> object, which executes a lambda expression that returns 1. The second starts a Task<Test> object, which executes a lambda expression that instantiates a new Test instance. The third starts a Task<String[]> object, which enumerates the files in the C:\Users\Public\Pictures\Sample Pictures\ directory. (Note that successful execution of the example requires that the directory exist and that it contain files.

C#

using System;
using System.Linq;
using System.Threading.Tasks;

class Program
{
    static void Main()
    {
        // Return a value type with a lambda expression
        Task<int> task1 = Task<int>.Factory.StartNew(() => 1);
        int i = task1.Result;

        // Return a named reference type with a multi-line statement lambda.
        Task<Test> task2 = Task<Test>.Factory.StartNew(() =>
        {
            string s = ".NET";
            double d = 4.0;
            return new Test { Name = s, Number = d };
        });
        Test test = task2.Result;

        // Return an array produced by a PLINQ query
        Task<string[]> task3 = Task<string[]>.Factory.StartNew(() =>
        {
            string path = @"C:\Users\Public\Pictures\Sample Pictures\";
            string[] files = System.IO.Directory.GetFiles(path);

            var result = (from file in files.AsParallel()
                          let info = new System.IO.FileInfo(file)
                          where info.Extension == ".jpg"
                          select file).ToArray();

            return result;
        });

        foreach (var name in task3.Result)
            Console.WriteLine(name);
    }
    class Test
    {
        public string Name { get; set; }
        public double Number { get; set; }
    }
}

Applies to

See also

• Task Parallel Library (TPL)
• Task-based Asynchronous Programming