Hello, Newsgroupians:

I'm a little confused when it comes to threads in C#.  Here's what I'm
trying to do...

I have a List<> containing a set of MyPoint(s)...

public struct MyPoint
{
 int x;
 int y;
 int val;
}

class MyClass
{
 List<MyPoint> m_list = new List<MyPoint>();
 ...
}

Now, in my main thread I'm going to populate the list.  Assume the
following...

class MyClass
{
 public MyClass()
 {
   for (int i = 0; i < 10; i++)
   {
     MyPoint pt = new MyPoint;
     pt.x = <Some X>
     pt.y = <Some Y>
     // pt.val is changed in the thread

     m_list.Add(pt);
   }
 }
 ...
}

Now, in the secondary thread, I am going to be changing .val
For simplicity, assume I do the following...

class MyClass
{
 void SomeFunc()
 {
   Thread th = new Thread(new ThreadStart(this.ThreadFunc));
   th.Start();
   while (th.IsAlive)  // Wait until the secondary thread is done
   {
     Thread.Sleep(1000);
   }
 
   for (int i = 0; i < m_list.Count; i++)
   {
     Console.WriteLine(m_list[i].val);
   }
 }

 public void ThreadFunc()
 {
   Random r = new Random();
   for (int i = 0; i < this.m_list.Count; i++)
   {
     MyPoint pt = this.m_list[i];
     pt.val = r.Next();
   }
   ...
 }
}

Yet, even after waiting for the secondary thread to end, the .val for each
MyPoint in the List<> is always zero.  I don't understand why it isn't
changing.  I've tried setting some variables to static; this didn't work.

Overall, what do I need to do to make it so the secondary thread can write
to the values in the List<> and have the main thread read these values once
the thread has ended?  Thank you.

Trecius