The custom progressbar code :

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Download_Videos
{
    public enum ProgressBarDisplayText
    {
        Percentage,
        CustomText
    }

    public partial class ProgressBarText : ProgressBar
    {
        //Property to set to decide whether to print a % or Text
        public ProgressBarDisplayText DisplayStyle { get; set; }

        //Property to hold the custom text
        public String CustomText { get; set; }

        public ProgressBarText()
        {
            // Modify the ControlStyles flags
            //http://msdn.microsoft.com/en-us/library/system.windows.forms.controlstyles.aspx
            SetStyle(ControlStyles.UserPaint | ControlStyles.AllPaintingInWmPaint | ControlStyles.OptimizedDoubleBuffer, true);
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            Rectangle rect = ClientRectangle;
            Graphics g = e.Graphics;

            ProgressBarRenderer.DrawHorizontalBar(g, rect);
            rect.Inflate(-3, -3);
            if (Value > 0)
            {
                // As we doing this ourselves we need to draw the chunks on the progress bar
                Rectangle clip = new Rectangle(rect.X, rect.Y, (int)Math.Round(((float)Value / Maximum) * rect.Width), rect.Height);
                ProgressBarRenderer.DrawHorizontalChunks(g, clip);
            }

            // Set the Display text (Either a % amount or our custom text
            int percent = (int)(((double)this.Value / (double)this.Maximum) * 100);
            string text = DisplayStyle == ProgressBarDisplayText.Percentage ? percent.ToString()   '%' : CustomText;

            using (Font f = new Font(FontFamily.GenericSerif, 10))
            {

                SizeF len = g.MeasureString(text, f);
                // Calculate the location of the text (the middle of progress bar)
                // Point location = new Point(Convert.ToInt32((rect.Width / 2) - (len.Width / 2)), Convert.ToInt32((rect.Height / 2) - (len.Height / 2)));
                Point location = new Point(Convert.ToInt32((Width / 2) - len.Width / 2), Convert.ToInt32((Height / 2) - len.Height / 2));
                // The commented-out code will centre the text into the highlighted area only. This will centre the text regardless of the highlighted area.
                // Draw the custom text
                g.DrawString(text, f, Brushes.Red, location);
            }
        }
    }
}

It's showing percentages fine but when i change it to display text in the constructor :

public Form1()
        {
            InitializeComponent();

            progressBarText1.DisplayStyle = ProgressBarDisplayText.CustomText;
        }

Then setting text :

private void ProgressChanged(object sender, DownloadProgressChangedEventArgs e, Stopwatch sw)
        {
            string downloadProgress = e.ProgressPercentage   "%";
            string downloadSpeed = string.Format("{0} MB/s", (e.BytesReceived / 1024.0 / 1024.0 / sw.Elapsed.TotalSeconds).ToString("0.00"));
            string downloadedMBs = Math.Round(e.BytesReceived / 1024.0 / 1024.0)   " MB";
            string totalMBs = Math.Round(e.TotalBytesToReceive / 1024.0 / 1024.0)   " MB";

            string progress = $"{downloadedMBs}/{totalMBs} ({downloadProgress}) @ {downloadSpeed}";

            label1.Text = progress;
            progressBarText1.CustomText = progress;
        }

the progressBar is empty there is nothing show on the progressBar. when i used :

progressBarText1.Value = e.ProgressPercentage;

it's showing the percentages in the center of the progressBar but the showing a text is not working it's just not showing anything.

CodePudding user response：

To me it looks like you need to call progressBarText1.Refresh() in ProgressChanged otherwise the code you wrote in the OnPaint override will not get executed.