How to pass and Reterive data from Thread - Part 3

To reterive data from a Thread, you need a delegate callback methdo.

step1 : Decalre the delegate for the callback method

public delegate void CallbackMethod(int anynum);


This delegare define the signature of the funtion which will be called by the Thread.

Step 2: Amend you call to accept delegate method while creating instance of the class

private CallbackMethod _callback;

public TypeSafe(int num, string msg, CallbackMethod callback)
{
_num = num;
_msg = msg;
_callback = callback;
}



Step 3: Amend the ThreadProc (procedure that will be running on the Thread) to make a call to callback method


public void ThreadProc()
{
Console.WriteLine(_msg, _num);

if (_callback != null)
{
_callback(_num + 100);
}
}


Step 4: Create a static function which you want to be called by the Thread. Note this should match the signature of the delegate


public static void ResultCallback(int n)
{
Console.WriteLine("result from callback is {0}", n);
}


Step 5: Pass the address of the method as a delegate instance


TypeSafe ts = new TypeSafe(100, "This is message from a TypeSafe Thread with num as {0}",new CallbackMethod(ResultCallback));


Compile and Run the code.

here is the complete code


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

namespace ThreadTypeSafe
{
class Program
{
static void Main(string[] args)
{
TypeSafe ts = new TypeSafe(100, "This is message from a TypeSafe Thread with num as {0}",new CallbackMethod(ResultCallback));
Thread t1 = new Thread(ts.ThreadProc);
t1.Start();
t1.Join();
Console.WriteLine("Main thread exiting");
Console.ReadKey();
}

public static void ResultCallback(int n)
{
Console.WriteLine("result from callback is {0}", n);
}

}

public delegate void CallbackMethod(int anynum);

public class TypeSafe
{
private int _num;
private string _msg;
private CallbackMethod _callback;

public TypeSafe(int num, string msg, CallbackMethod callback)
{
_num = num;
_msg = msg;
_callback = callback;
}

public void ThreadProc()
{
Console.WriteLine(_msg, _num);

if (_callback != null)
{
_callback(_num + 100);
}
}

}
}