private double SetProgressBar(int val, int max = -1) { if (max >= 0) { Progressbar.Maximum = max; } Progressbar.Value = val; // perc var perc = (double)Progressbar.Value * 100 / Progressbar.Maximum; Progressbar.CreateGraphics().DrawString(perc.ToString("f0") + "%", new Font("微软雅黑 Light", 15, FontStyle.Regular, GraphicsUnit.Pixel), Brushes.Magenta, new PointF(Progressbar.Width / 2 - 15, Progressbar.Height / 2 - 10)); return(perc); }