change label.text in any step in the loop

I want in this code in the any step label show the Number of that step. In the my code just show last number in the label!

i can do it with doevent() but I think at times face with problem

enter code here 
    private void button1_Click(object sender, EventArgs e)
    {
        int i = 0;
        while (i<100)
        {
            i++;
            label1.Text = string.Format("Step is :{0}", i);

            Application.DoEvents();
            label1.Inval开发者_如何学Goidate();
            System.Threading.Thread.Sleep(1000);

        }
    }

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Assuming you want the counter to update the label while still performing the actions of Application.DoEvents(), you will likely need to run the tasks on a separate thread, else the code will execute and return the result after the thread has been released back to the application.