Task<TResult>.Factory Property
Definition
Important
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Gets a factory method for creating and configuring Task<TResult> instances.
public:
static property System::Threading::Tasks::TaskFactory<TResult> ^ Factory { System::Threading::Tasks::TaskFactory<TResult> ^ get(); };public static System.Threading.Tasks.TaskFactory<TResult> Factory { get; }static member Factory : System.Threading.Tasks.TaskFactory<'Result>Public Shared ReadOnly Property Factory As TaskFactory(Of TResult)Property Value
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:
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 the .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.
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; }
}
}
Imports System.Threading.Tasks
Module Module1
Sub Main()
ReturnAValue()
Console.WriteLine("Press any key to exit.")
Console.ReadKey()
End Sub
Sub ReturnAValue()
' Return a value type with a lambda expression
Dim task1 = Task(Of Integer).Factory.StartNew(Function() 1)
Dim i As Integer = task1.Result
' Return a named reference type with a multi-line statement lambda.
Dim task2 As Task(Of Test) = Task.Factory.StartNew(Function()
Dim s As String = ".NET"
Dim d As Integer = 4
Return New Test With {.Name = s, .Number = d}
End Function)
Dim myTest As Test = task2.Result
Console.WriteLine(myTest.Name & ": " & myTest.Number)
' Return an array produced by a PLINQ query.
Dim task3 As Task(Of String())= Task(Of String()).Factory.StartNew(Function()
Dim path = "C:\Users\Public\Pictures\Sample Pictures\"
Dim files = System.IO.Directory.GetFiles(path)
Dim result = (From file In files.AsParallel()
Let info = New System.IO.FileInfo(file)
Where info.Extension = ".jpg"
Select file).ToArray()
Return result
End Function)
For Each name As String In task3.Result
Console.WriteLine(name)
Next
End Sub
Class Test
Public Name As String
Public Number As Double
End Class
End Module
