Thread Constructor (ParameterizedThreadStart)

Parameters

• start
  Type: System.Threading.ParameterizedThreadStart
  A delegate that represents the methods to be invoked when this thread begins executing.

Imports System.Threading

Public Class Example

   Private Shared outputBlock As System.Windows.Controls.TextBlock

   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)

      Example.outputBlock = outputBlock

      ' To start a thread using a static thread procedure, use the
      ' class name and method name when you create the 
      ' ParameterizedThreadStart delegate. Visual Basic expands the 
      ' AddressOf expression to the appropriate delegate creation 
      ' syntax:
      '    New ParameterizedThreadStart(AddressOf Example.DoWork)
      '
      Dim newThread As New Thread(AddressOf Example.DoWork)
      newThread.Start(42)

   End Sub

   ' Simulate work. To communicate with objects on the UI thread, get the 
   ' Dispatcher for one of the UI objects. Use the Dispatcher object's 
   ' BeginInvoke method to queue a delegate that will run on the UI thread,
   ' and therefore can safely access UI elements like the TextBlock.
   Private Shared Sub DoWork(ByVal state As Object)

      Dim data As Integer = CInt(state)
      Dim display As New Action(Of String)(AddressOf DisplayOutput)

      outputBlock.Dispatcher.BeginInvoke(display, _
         String.Format("Shared thread procedure. Data={0}" & vbLf, data))

   End Sub

   ' The Dispatcher.BeginInvoke method runs this helper method on the 
   ' UI thread, so it can safely access the TextBlock that is used to 
   ' display the output.
   Private Shared Sub DisplayOutput(msg)
      outputBlock.Text &= msg
   End Sub

End Class

' This code example produces the following output:
'
'Shared thread procedure. Data='42'

using System;
using System.Threading;

public class Example
{
   private static System.Windows.Controls.TextBlock outputBlock;

   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      Example.outputBlock = outputBlock;

      // To start a thread using a shared thread procedure, use
      // the class name and method name when you create the 
      // ParameterizedThreadStart delegate. C# infers the 
      // appropriate delegate creation syntax:
      //    New ParameterizedThreadStart(Example.DoWork)
      //
      Thread newThread = new Thread(Example.DoWork);
      newThread.Start(42);
   }

   // Simulate work. To communicate with objects on the UI thread, get the 
   // Dispatcher for one of the UI objects. Use the Dispatcher object's 
   // BeginInvoke method to queue a delegate that will run on the UI thread,
   // and therefore can safely access UI elements like the TextBlock.
   private static void DoWork(object state)
   {
      int data = (int) state;

      outputBlock.Dispatcher.BeginInvoke(delegate () { 
         outputBlock.Text += String.Format("Static thread procedure. Data={0}\n", data); 
      });
   }
}

/* This code example produces the following output:

Static thread procedure. Data=42
 */