Question

how to use ParameterizedThreadStart in c# I want to make threads take void method and this method take sqlconnection ?

Answer 1

The ParameterizedThreadStart delegate only takes an Object parameter, so the method has to match that. You have to cast the Object reference to SqlConnection in the method:

public void Work(Object o) {
  SqlConnection conn = o as SqlConnection;
  ...
}

When calling it you don’t have to specifically cast the SqlConnection to Object, that is done implicitly:

Thread t = new Thread(Work);
t.Start(conn);

However, you might want to consider that the method should create it’s own connection. The connection object is not thread safe, so you can’t use the same connetion object in more than one thread at a time.