在ProgressBar上闪烁文本

Question

I wrote a control. And when i execute program text on progressbar is blinking.

     public class ProgressBarPercentage : ProgressBar
        {
            private int percent;//user defined step

            public void SetProgressBarText(string text)
            {
                using (Graphics gr = this.CreateGraphics())
                {
                    this.Refresh();
                    gr.DrawString(percent.ToString() + " %", SystemFonts.DefaultFont, Brushes.Black,
                        new PointF(this.Width / 2 - (gr.MeasureString(percent.ToString() + " %", SystemFonts.DefaultFont).Width / 2.0F),
                        this.Height / 2 - (gr.MeasureString(percent.ToString() + " %", SystemFonts.DefaultFont).Height / 2.0F)));
                }
            }

            public void SetPercent(int percent)
            {
                this.percent = percent;
                if (this.Value < 100)
                    this.Value = percent;
                else
                    this.Value = 99;

            }
        }

static void Main
{
            ProgressBarWindow.ProgressBarPercentage progress = new ProgressBarWindow.ProgressBarPercentage();
    for (int i = 0; i < 100; i++)
    {     
        progress.SetPercent(i);
        progress.SetProgressBarText(i.ToString());
    }
}   

Can you say me what I did wrong?

Answer 1

I do not think, You will see the blink effect by this, even if it works.

This is simply too fast.

You must perhaps use a timer to reduce the speed, or, also possible, System.Thread.Sleep()

Answer 2

I know this question was asked long time ago, but maybe this answer would be helpful for someone with similar problem. You can set style in constructor for this custom control like this:

SetStyle(ControlStyles.UserPaint | ControlStyles.AllPaintingInWmPaint | ControlStyles.OptimizedDoubleBuffer, true);

Most important is ControlStyles.OptimizedDoubleBuffer flag which can prevent controls from blinking when Paint is called in too short intervals.

Source: http://msdn.microsoft.com/pl-pl/library/system.windows.forms.controlstyles.aspx