ThreadPool.QueueUserWorkItem is not working in C# Console

Question

I am trying to use ThreadPool in C# Console application as shown below. static void Main( string [] args) { for (var i = 1; i { ThreadPool.QueueUserWorkItem(n => { Console.WriteLine($ "Start operation {n}" ); Thread.Sleep(1000); // Simulate long running operation Console.WriteLine($ "Operation {n} completed" ); }, i); } Console.ReadKey(); } But it is showing the below error: The type or namespace name " QueueUserWorkItem " does not exist in the namespace "ThreadPool". What I am doing wrong or which reference I need to add. I have already used the namespace system.Threading. I am working on .Net framework version 4.6.

Suraj Kumar · Answer

I got my solution as the project name was also ThreadPool so it was not working. Now I have changed the name of project and now ThreadPool.QueueUserWorkItem is working. Previously my project was something like this. namespace ThreadPool { class Program { static void Main( string [] args) { for (var i = 1; i { ThreadPool.QueueUserWorkItem(n => { Console.WriteLine($ "Start operation {n}" ); Thread.Sleep(1000); // Simulate long running operation Console.WriteLine($ "Operation {n} completed" ); }, i); } Console.ReadKey(); } } } Now I have changed it to as below and is working now. namespace MyThreadPool { class Program { static void Main( string [] args) { for (var i = 1; i { ThreadPool.QueueUserWorkItem(n => { Console.WriteLine($ "Start operation {n}" ); Thread.Sleep(1000); // Simulate long running operation Console.WriteLine($ "Operation {n} completed" ); }, i); } Console.ReadKey(); } } }