C# SmoothProgressBar自定义进度条控件

using System;
 using System.Collections;
 using System.ComponentModel;
 using System.Drawing;
 using System.Data;
 using System.Windows.Forms;namespace SmoothProgressBar
 {
     /// <summary>
     /// UserControl1 的摘要说明。
     /// </summary>
     public class SmoothProgressBar : System.Windows.Forms.UserControl
     {
         /// <summary>
         /// 必需的设计器变量。
         /// </summary>
         private System.ComponentModel.Container components = null;        public SmoothProgressBar()
         {
             // 该调用是 Windows.Forms 窗体设计器所必需的。
             InitializeComponent();            // TODO: 在 InitComponent 调用后添加任何初始化
        }
        /// <summary>
         /// 清理所有正在使用的资源。
         /// </summary>
         protected override void Dispose( bool disposing )
         {
             if( disposing )
             {
                 if( components != null )
                     components.Dispose();
             }
             base.Dispose( disposing );
         }        #region 组件设计器生成的代码
         /// <summary>
         /// 设计器支持所需的方法 - 不要使用代码编辑器 
         /// 修改此方法的内容。
         /// </summary>
         private void InitializeComponent()
         {
             // 
             // SmoothProgressBar
             // 
             this.Name = "SmoothProgressBar";        }
         #endregion        int min = 0; // Minimum value for progress range
         int max = 100; // Maximum value for progress range
         int val = 0;  // Current progress
         Color BarColor = Color.Blue;  // Color of progress meter        protected override void OnResize(EventArgs e)
         {
             // Invalidate the control to get a repaint.
             this.Invalidate();
         }        protected override void OnPaint(PaintEventArgs e)
         {
             Graphics g = e.Graphics;
             SolidBrush brush = new SolidBrush(BarColor);
             float percent = (float)(val - min) / (float)(max - min);
             Rectangle rect = this.ClientRectangle;            // Calculate area for drawing the progress.
             rect.Width = (int)((float)rect.Width * percent);            // Draw the progress meter.
             g.FillRectangle(brush, rect);            // Draw a three-dimensional border around the control.
             Draw3DBorder(g);            // Clean up.
             brush.Dispose();
             g.Dispose();  
         }        public int Minimum
         {
             get
             {
                 return min;
             }            set
             {
                 // Prevent a negative value.
                 if (value < 0)
                 {
                     min = 0;
                 }
   
                 // Make sure that the minimum value is never set higher than the maximum value.
                 if (value > max)
                 {
                     min = value;
                     min = value;
                 }
   
                 // Ensure value is still in range
                 if (val < min)
                 {
                     val = min;
                 }                // Invalidate the control to get a repaint.
                 this.Invalidate();
             }
         }        public int Maximum
         {
             get
             {
                 return max;
             }            set
             {
                 // Make sure that the maximum value is never set lower than the minimum value.
                 if (value < min)
                 {
                     min = value;
                 }                max = value;
                // Make sure that value is still in range.
                 if (val > max)
                 {
                     val = max;
                 }                // Invalidate the control to get a repaint.
                 this.Invalidate();
             }
         }        public int Value
         {
             get
             {
                 return val;
             }            set
             {
                 int oldValue = val;                // Make sure that the value does not stray outside the valid range.
                 if (value < min)
                 {
                     val = min;
                 }
                 else if (value > max)
                 {
                     val = max;
                 }
                 else
                 {
                     val = value;
                 }                // Invalidate only the changed area.
                 float percent;                Rectangle newValueRect = this.ClientRectangle;
                 Rectangle oldValueRect = this.ClientRectangle;                // Use a new value to calculate the rectangle for progress.
                 percent = (float)(val - min) / (float)(max - min);
                 newValueRect.Width = (int)((float)newValueRect.Width * percent);                // Use an old value to calculate the rectangle for progress.
                 percent = (float)(oldValue - min) / (float)(max - min);
                 oldValueRect.Width = (int)((float)oldValueRect.Width * percent);                Rectangle updateRect = new Rectangle();
   
                 // Find only the part of the screen that must be updated.
                 if (newValueRect.Width > oldValueRect.Width)
                 {
                     updateRect.X = oldValueRect.Size.Width;
                     updateRect.Width = newValueRect.Width - oldValueRect.Width;
                 }
                 else
                 {
                     updateRect.X = newValueRect.Size.Width;
                     updateRect.Width = oldValueRect.Width - newValueRect.Width;
                 }                updateRect.Height = this.Height;
                // Invalidate the intersection region only.
                 this.Invalidate(updateRect);
             }
         }        public Color ProgressBarColor
         {
             get
             {
                 return BarColor;
             }            set
             {
                 BarColor = value;                // Invalidate the control to get a repaint.
                 this.Invalidate();
             }
         }        private void Draw3DBorder(Graphics g)
         {
             int PenWidth = (int)Pens.White.Width;            g.DrawLine(Pens.DarkGray, 
                 new Point(this.ClientRectangle.Left, this.ClientRectangle.Top),
                 new Point(this.ClientRectangle.Width - PenWidth, this.ClientRectangle.Top));
             g.DrawLine(Pens.DarkGray,
                 new Point(this.ClientRectangle.Left, this.ClientRectangle.Top), 
                 new Point(this.ClientRectangle.Left, this.ClientRectangle.Height - PenWidth));
             g.DrawLine(Pens.White,
                 new Point(this.ClientRectangle.Left, this.ClientRectangle.Height - PenWidth), 
                 new Point(this.ClientRectangle.Width - PenWidth, this.ClientRectangle.Height - PenWidth));
             g.DrawLine(Pens.White,
                 new Point(this.ClientRectangle.Width - PenWidth, this.ClientRectangle.Top), 
                 new Point(this.ClientRectangle.Width - PenWidth, this.ClientRectangle.Height - PenWidth));
         } 
     }
 }