CODEWITHSUNDEEP
c#multithreadingwinforms
mohsenet
mohsenet

Reputation: 5

thread.name give me two different answers in my code

I got two ways out of the program.

First:

namespace FirstTheard
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            this.StartPosition = FormStartPosition.CenterScreen;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Thread T1 = new Thread(new ThreadStart(DoWork));
            T1.Name = "Primery Thread";
            T1.Start();

        }

        private void DoWork()
        {
            var threadName = Thread.CurrentThread.Name;
            for (int i = 0; i <= 20; i++)
            {
                Invoke(new Action(() =>
                { 
                    label1.Text += "ThreadName is-------"+threadName+"\n";
                }));
                Thread.Sleep(100);
            }

        }
    }
}

Output:
ThreadName is-------Primary Thread

Second:

namespace FirstTheard
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            this.StartPosition = FormStartPosition.CenterScreen;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Thread T1 = new Thread(new ThreadStart(DoWork));
            T1.Name = "Primery Thread";
            T1.Start();

        }

        private void DoWork()
        {
            //var threadName = Thread.CurrentThread.Name;
            for (int i = 0; i <= 20; i++)
            {
                Invoke(new Action(() =>
                { 
                    label1.Text += "ThreadName is-------"+ Thread.CurrentThread.Name + "\n";
                }));
                Thread.Sleep(100);
            }

        }
    }
}

Output:
ThreadName is-------

Why are two outputs different?

please help me

Upvotes: 0

Views: 81

Answers (4)

mohsenet
mohsenet

Reputation: 5

I think I understood Thank you everybody

This code show my means

namespace FirstTheard

{ public partial class Form1 : Form { public string CurrentThread; public Form1() { InitializeComponent();

        this.StartPosition = FormStartPosition.CenterScreen;
    }

    private void button1_Click(object sender, EventArgs e)
    {
        //Position of thread now is "Primery Thread"
        CurrentThread = Thread.CurrentThread.Name= "Primery Thread";
        label1.Text = CurrentThread + "\n";
        Thread T1 = new Thread(new ThreadStart(DoWork));
        T1.Name = "Secondery Thread";
        T1.Start();
    }

    private void DoWork()
    {
        //Position of thread now is "Secondary Thread" or T1
        var threadName = Thread.CurrentThread.Name;
        for (int i = 0; i <= 20; i++)
        {
            Invoke(new Action(() =>
            {
                //Position of thread now is "Primery Thread" again
                label1.Text += "ThreadName at T1 is-------"+ threadName + "         " + "ThreadName in the Invoke is-------" + Thread.CurrentThread.Name+ "\n";
            }));
            Thread.Sleep(100);
        }

    }

}

}

Upvotes: 0

Vikhram
Vikhram

Reputation: 4394

In the first sample, you are accessing the Thread.CurrentThread.Name in the Thread t1 i.e. the t1.Name

Whereas, in the second sample, you are accessing the Thread.CurrentThread.Name within Invoke, which, in this case will be the main GUI/Event thread, which does not have any name. Remember, Invoke will execute the specified delegate on the thread that owns the control's underlying window handle.

Upvotes: 1

Daniel A. White
Daniel A. White

Reputation: 190925

Invoke returns control back to the UI thread.

Upvotes: 1

dymanoid
dymanoid

Reputation: 15197

Thread.CurrentThread.Name gives you the name of the thread which reads this property.

In the first case, you access (read) this property on your created thread T1. In the second case, you access the property on the UI thread (because of calling via Invoke). And since you didn't set any name for the main UI thread, the property returns an empty string.

Upvotes: 7

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