Question

I am working my way through a book called Head First C#. It doesnt explain what the loop is saying in detail. It would be great if someone can explain the part I dont understand.
The way I am reading this is as long as c is less than 254 and visible c will increase by 1 each time the loop is gone through. What I dont understand is the (c, 255 – c, c)

private void button1_Click(object sender, EventArgs e)
    {

        while (Visible)
        {
            for (int c = 0; c < 254 && Visible; c++)
            {
                this.BackColor = Color.FromArgb(c, 255 - c, c);
                Application.DoEvents();
                System.Threading.Thread.Sleep(5);
            }
        }
    }

Answer 1

this.BackColor = Color.FromArgb(c, 255 - c, c);

The arguments to that function are red, green, blue. The maximum value is 255 and the minimum value is 0. This function fades the color from full green into no green, full red-blue (magenta).

for (int c = 0; c < 254 && Visible; c++)

The loop will continue until either the form is made invisible (assuming this event handler is on a form, Visible refers to this.Visible and will be false if the form is hidden), or the maximum value is reached (c < 254 will be false).

Here’s a chart that shows the common colors based on their red, green, and blue values. In the chart, the format is RRGGBB, where RR is the red value, GG is the green value, and BB is the blue value. The numbers are in hex (runs from 0 to FF instead of 0 to 255).