正在进行中效果

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

namespace TestApplication1
{
    public partial class ProgressPic : UserControl
    {
        Timer ti;
        byte buffer = 0;

        public ProgressPic()
        {
            InitializeComponent();
            ti = new Timer();
            ti.Interval = 1000;
            ti.Tick += new EventHandler(ti_Tick);
            ti.Start();
        }

        void ti_Tick(object sender, EventArgs e)
        {
            label1.Refresh();
            label2.Refresh();
            label3.Refresh();
            label4.Refresh();
            label5.Refresh();
            buffer++;
            if (buffer > 4)
                buffer = 0;
            SolidBrush b = new SolidBrush(Color.Violet);
            Rectangle rc = new Rectangle(0, 0, label1.Width, label1.Height);
            switch (buffer)
            {
                case 0:
                    {
                        Graphics g = label5.CreateGraphics();
                        g.FillRectangle(b, rc);
                        g.Dispose();
                    }
                    break;
                case 1:
                    {
                        Graphics g = label1.CreateGraphics();
                        g.FillRectangle(b, rc);
                        g.Dispose();
                    }
                    break;
                case 2:
                    {
                        Graphics g = label2.CreateGraphics();
                        g.FillRectangle(b, rc);
                        g.Dispose();
                    }
                    break;
                case 3:
                    {
                        Graphics g = label3.CreateGraphics();
                        g.FillRectangle(b, rc);
                        g.Dispose();
                    }
                    break;
                case 4:
                    {
                        Graphics g = label4.CreateGraphics();
                        g.FillRectangle(b, rc);
                        g.Dispose();
                    }
                    break;
            }
            b.Dispose();
        }
    }
}