it was working fine first time when i dragged the custom progressbar to the form1 designer from the toolbox. but now each time i try to drag it i get the exception error message.

and i didn’t change anything.

link for the code where i took it from.

https://github.com/ukushu/TextProgressBar/blob/master/TextProgressBar.cs

here is an image screenshot showing the error message:

and the code

protected override void OnPaint(PaintEventArgs e)
{
    if (e.Graphics == null)
    {
        return;
    }

    Graphics g = e.Graphics;

    DrawProgressBar(g);

    DrawStringIfNeeded(g);
}

line 134 is:

DrawStringIfNeeded(g);

and

private void DrawStringIfNeeded(Graphics g)
{
    if (VisualMode != ProgressBarDisplayMode.NoText)
    {
        string text = _textToDraw;

        if (!string.IsNullOrEmpty(text))
        {
            SizeF len = g.MeasureString(text, TextFont);

            Point location = new Point((Width / 2) - (int)len.Width / 2, (Height / 2) - (int)len.Height / 2);

            g.DrawString(text, TextFont, _textColourBrush, location);
        }
    }
}

line 165 is:

g.DrawString(text, TextFont, _textColourBrush, location);

and the full code , it’s a bit long but might be needed:

using System;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;

public enum ProgressBarDisplayMode
{
    NoText,
    Percentage,
    CurrProgress,
    CustomText,
    TextAndPercentage,
    TextAndCurrProgress
}

public class CustomProgressBar : ProgressBar
{
    [Description("Font of the text on ProgressBar"), Category("Additional Options")]
    public Font TextFont { get; set; } = new Font(FontFamily.GenericSerif, 14, FontStyle.Bold | FontStyle.Italic);

    private SolidBrush _textColourBrush = (SolidBrush)Brushes.Black;
    [Category("Additional Options")]
    public Color TextColor
    {
        get
        {
            return _textColourBrush.Color;
        }
        set
        {
            _textColourBrush.Dispose();
            _textColourBrush = new SolidBrush(value);
        }
    }

    private SolidBrush _progressColourBrush = (SolidBrush)Brushes.LightGreen;
    [Category("Additional Options"), Browsable(true), EditorBrowsable(EditorBrowsableState.Always)]
    public Color ProgressColor
    {
        get
        {
            return _progressColourBrush.Color;
        }
        set
        {
            _progressColourBrush.Dispose();
            _progressColourBrush = new SolidBrush(value);
        }
    }

    private ProgressBarDisplayMode _visualMode = ProgressBarDisplayMode.Percentage;
    [Category("Additional Options"), Browsable(true)]
    public ProgressBarDisplayMode VisualMode
    {
        get
        {
            return _visualMode;
        }
        set
        {
            _visualMode = value;
            Invalidate(); // Redraw component after change value from VS Properties section
        }
    }

    private string _text = string.Empty;

    [Description("If it's empty, % will be shown"), Category("Additional Options"), Browsable(true), EditorBrowsable(EditorBrowsableState.Always)]
    public string CustomText
    {
        get
        {
            return _text;
        }
        set
        {
            _text = value;
            Invalidate(); // Redraw component after change value from VS Properties section
        }
    }

    private string _textToDraw
    {
        get
        {
            string text = CustomText;

            switch (VisualMode)
            {
                case ProgressBarDisplayMode.Percentage:
                    text = _percentageStr;
                    break;
                case ProgressBarDisplayMode.CurrProgress:
                    text = _currProgressStr;
                    break;
                case ProgressBarDisplayMode.TextAndCurrProgress:
                    text = $"{CustomText}: {_currProgressStr}";
                    break;
                case ProgressBarDisplayMode.TextAndPercentage:
                    text = $"{CustomText}: {_percentageStr}";
                    break;
            }

            return text;
        }
    }

    private string _percentageStr => $"{(int)((float)Value - Minimum) / ((float)Maximum - Minimum) * 100} %";

    private string _currProgressStr => $"{Value}/{Maximum}";

    public CustomProgressBar()
    {
        Value = Minimum;
        FixComponentBlinking();
    }

    private void FixComponentBlinking()
    {
        SetStyle(ControlStyles.UserPaint | ControlStyles.AllPaintingInWmPaint | ControlStyles.OptimizedDoubleBuffer, true);
    }

    protected override void OnPaint(PaintEventArgs e)
    {
        if (e.Graphics == null)
        {
            return;
        }

        Graphics g = e.Graphics;

        DrawProgressBar(g);

        DrawStringIfNeeded(g);
    }

    private void DrawProgressBar(Graphics g)
    {
        Rectangle rect = ClientRectangle;

        ProgressBarRenderer.DrawHorizontalBar(g, rect);

        rect.Inflate(-3, -3);

        if (Value > 0)
        {
            Rectangle clip = new Rectangle(rect.X, rect.Y, (int)Math.Round(((float)Value / Maximum) * rect.Width), rect.Height);

            g.FillRectangle(_progressColourBrush, clip);
        }
    }

    private void DrawStringIfNeeded(Graphics g)
    {
        if (VisualMode != ProgressBarDisplayMode.NoText)
        {
            string text = _textToDraw;

            if (!string.IsNullOrEmpty(text))
            {
                SizeF len = g.MeasureString(text, TextFont);

                Point location = new Point((Width / 2) - (int)len.Width / 2, (Height / 2) - (int)len.Height / 2);

                g.DrawString(text, TextFont, _textColourBrush, location);
            }
        }
    }

    protected override void Dispose(bool disposing)
    {
        if (disposing)
        {
            _textColourBrush?.Dispose();
            _progressColourBrush?.Dispose();
        }
        base.Dispose(disposing);
    }
}