Thread t = Thread.CurrentThread;
Console.WriteLine("Name before: [" + t.Name + "]");
Console.WriteLine("Name is null: " + (t.Name == null));
t.Name = "Main Thread";
Console.WriteLine("t.Name: " + t.Name);
Console.WriteLine("Thread.CurrentThread.Name: " + Thread.CurrentThread.Name);

static void Method2()
{
    for (int i = 1; i <= 3; i++)
    {
        if (i == 2)
        {
            Console.WriteLine("Method2: database operation started");
            Thread.Sleep(5000);   // pretend this is a slow DB call
            Console.WriteLine("Method2: database operation completed");
        }
        Console.WriteLine("Method2: " + i);
    }
}

Stopwatch sw = Stopwatch.StartNew();
Thread.CurrentThread.Name = "Main";
Console.WriteLine("Main started");
Thread t1 = new Thread(Method1) { Name = "Thread1" };
Thread t2 = new Thread(Method2) { Name = "Thread2" };
Thread t3 = new Thread(Method3) { Name = "Thread3" };
t1.Start();
t2.Start();
t3.Start();
Console.WriteLine("Main ended after " + sw.Elapsed.TotalSeconds.ToString("0.0") + " s");

class MyThread : Thread
{
}

Program.cs(4,18): error CS0509: 'MyThread': cannot derive from sealed type 'Thread'

Thread t1 = new Thread(DisplayNumbers) { Name = "t1" };
ThreadStart ts = new ThreadStart(DisplayNumbers);
Thread t2 = new Thread(ts) { Name = "t2" };
Thread t3 = new Thread(new ThreadStart(DisplayNumbers)) { Name = "t3" };
Thread t4 = new Thread(delegate () { DisplayNumbers(); }) { Name = "t4" };
Thread t5 = new Thread(() => DisplayNumbers()) { Name = "t5" };

NumberHelper obj = new NumberHelper("hi");
Thread t1 = new Thread(obj.DisplayNumbers);
t1.Start();

Program.cs(24,45): error CS1503: Argument 1: cannot convert from 'string' to 'int'

ResultCallback callback = new ResultCallback(ShowResult);
NumberHelper obj = new NumberHelper(10, callback);
Thread t1 = new Thread(obj.CalculateSum);
t1.Start();
static void ShowResult(int result)
{
    Console.WriteLine("Sum of the numbers is: " + result);
}

Thread t = new Thread(Work);
Console.WriteLine("1) after new:       " + t.ThreadState + ", IsAlive = " + t.IsAlive);
t.Start();
Thread.Sleep(500);   // give the worker time to reach its Sleep
Console.WriteLine("3) while it sleeps: " + t.ThreadState + ", IsAlive = " + t.IsAlive);
t.Join();
Console.WriteLine("5) after Join:      " + t.ThreadState + ", IsAlive = " + t.IsAlive);

static void Work()
{
    Console.WriteLine("2) inside Work:     " + Thread.CurrentThread.ThreadState);
    Thread.Sleep(2000);
    Console.WriteLine("4) Work is about to end");
}

1) after new:       Unstarted, IsAlive = False
2) inside Work:     Running
3) while it sleeps: WaitSleepJoin, IsAlive = True
4) Work is about to end
5) after Join:      Stopped, IsAlive = False

Thread oThread = new Thread(MethodJoin);   // prints "work is in progress..!" 3 times
oThread.Start();
oThread.Join();
Console.WriteLine("work completed..!");

Thread oThread = new Thread(WorkThread);
oThread.Start();
Console.WriteLine("Main Thread Quits..!");

static void WorkThread()
{
    for (int i = 0; i <= 4; i++)
    {
        Console.WriteLine("Worker Thread is in progress..!");
        Thread.Sleep(2000); // sleep for 2 seconds
    }
    Console.WriteLine("Worker Thread Quits..!");
}

Thread oThread = new Thread(WorkThread);
oThread.IsBackground = true;
oThread.Start();
Console.WriteLine("Main Thread Quits..!");

Thread t = new Thread(Work) { Name = "Worker" };
Console.WriteLine("A: " + t.ThreadState);
Console.WriteLine("B: " + t.IsBackground);
t.Start();
Thread.Sleep(1000);
Console.WriteLine("C: " + t.ThreadState + " " + t.IsAlive);
t.Join();
Console.WriteLine("D: " + t.ThreadState + " " + t.IsAlive);
static void Work()
{
    Thread me = Thread.CurrentThread;
    Console.WriteLine("W: " + me.Name + " " + me.ThreadState);
    Thread.Sleep(3000);
}

A: Unstarted
B: False
W: Worker Running
C: WaitSleepJoin True
D: Stopped False

Stopwatch sw = Stopwatch.StartNew();
Download(); Resize(); Save();
Console.WriteLine("One thread:    " + sw.Elapsed.TotalSeconds.ToString("0.0") + " s");
sw.Restart();
Thread t1 = new Thread(Download);
Thread t2 = new Thread(Resize);
Thread t3 = new Thread(Save);
t1.Start(); t2.Start(); t3.Start();
t1.Join(); t2.Join(); t3.Join();
Console.WriteLine("Three threads: " + sw.Elapsed.TotalSeconds.ToString("0.0") + " s");
static void Download() { Thread.Sleep(2000); }
static void Resize()   { Thread.Sleep(3000); }
static void Save()     { Thread.Sleep(1000); }

One thread:    6.0 s
Three threads: 3.0 s

Thread worker = new Thread(Tick);
worker.Start();
Thread.Sleep(1500);
Console.WriteLine("Main done");
static void Tick()
{
    for (int i = 1; i <= 3; i++)
    {
        Console.WriteLine("tick " + i);
        Thread.Sleep(1000);
    }
    Console.WriteLine("Worker done");
}

Thread t = new Thread(PrintSquares);
t.Start(4);
t.Join();
Console.WriteLine("Main done");
static void PrintSquares(object max)
{
    int n = Convert.ToInt32(max);
    for (int i = 1; i <= n; i++)
        Console.WriteLine(i + " x " + i + " = " + (i * i));
}