Richtextbox multiple back colors

Question

I saw this cool thing about having a RichTextBox like a "progress bar" if we can call it like that from another window application and I was trying to do the same.

I was looking at the methods and I couldn't apply any of them on what I'm looking for, I tried to see if there was a similar question but I didn't get so lucky.

How can I accomplish the same result?

Looks like a Richtextbox to me

Based on what Jimi told me I will to explain what I need. The string inside label rappresents a timer which has to change the color in red when it reaches the end, before of that, like at 10 minutes I want it to be Yellow, using that like an alert.

The way the method is wroten doesn't let me to choose which color I want. After that, when the timer is stopped by a button, I want the label to redraws itself and makes it blank without having any kind of colors, looking like a "textbox".

Answer 1

This is a label used as a ProgressBar.
Just an example (quite raw, what I could do with the time I had), but it shows how you can paint the surface of a Control that provides a Paint() event.

It uses a Timer class to increase a value and generates a progress bar effect by calling the Label.Invalidate() method, which raises the Label's Paint event, executing whatever code you have in the label1_Paint() handler.

If you want to test it, paste this code inside a Form which contains a Button (button1) to start the Timer and a Label (label1) that generates the graphic effect.
Then assign the two events - Click() to the Button and Paint() to the Label.

This is how it looks like:

Timer timer;
private bool TimerStarted = false;
private float ProgressMaxValue = 100;
private float Progress = 0;
private int seconds = 0;
private int cents = 0;

private void button1_Click(object sender, EventArgs e)
{
    if (TimerStarted) { TimerStop(); return; }
    timer = new Timer();
    timer.Interval = 20;
    Progress = 0;
    seconds = 0;
    cents = 0;
    timer.Tick += (s, ev) => {
        ++Progress;
        if (Progress > ProgressMaxValue) { TimerStop(); return; }
        cents += (timer.Interval / 5);
        if (cents > 99) { cents = 0; ++seconds; }
        this.label1.Invalidate();
    };
    TimerStarted = true;
    timer.Start();
}

private void TimerStop()
{
    timer.Stop();
    timer.Dispose();
    TimerStarted = false;
}

private void label1_Paint(object sender, PaintEventArgs e)
{
    StringFormat format = new StringFormat() {
        Alignment = StringAlignment.Center,
        LineAlignment = StringAlignment.Center
    };

    e.Graphics.Clear(this.label1.BackColor);
    Rectangle rect = label1.ClientRectangle;
    rect.Inflate(-1, -1);
    e.Graphics.DrawRectangle(Pens.LimeGreen, rect);
    RectangleF ProgressBar = new RectangleF(
                new PointF(3, 3),
                new SizeF((((float)rect.Width - 3) / ProgressMaxValue) * Progress, rect.Height - 4));
    e.Graphics.FillRectangle(Brushes.YellowGreen, ProgressBar);
    e.Graphics.DrawString($"0.{seconds.ToString("D2")}.{cents.ToString("D2")}", label1.Font, Brushes.White, rect, format);
}