c# 可以旋转的 饼形图

其中用到了 timer控件

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;
using System.Data.SqlClient;

namespace RoundCaky
{
    public partial class Frm_Main : Form
    {
        public class PyPanel : Panel
        {
            public PyPanel（）
            {
                Setstyle（Controlstyles.OptimizedDoubleBuffer | Controlstyles.AllPaintingInWmPaint true）;
                Updatestyles（）;
            }
        }
        public Frm_Main（）
        {
            InitializeComponent（）;
        }
        SqlConnection con;
        SqlCommand cmd;
        
        private void Conn（）
        {
            con = new SqlConnection（“server=WRET-MOSY68

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----
     目录           0  2011-12-22 23:11  RoundCaky\
     文件         917  2013-05-09 17:39  RoundCaky.sln
     文件       17920  2010-11-04 04:50  RoundCaky.suo
     目录           0  2011-12-22 23:11  RoundCaky\bin\
     目录           0  2013-05-09 17:59  RoundCaky\bin\Debug\
     文件       11264  2013-05-09 17:59  RoundCaky\bin\Debug\RoundCaky.exe
     文件       26112  2013-05-09 17:59  RoundCaky\bin\Debug\RoundCaky.pdb
     文件        5753  2013-05-09 18:07  RoundCaky\Frm_Main.cs
     文件        3651  2010-07-10 19:13  RoundCaky\Frm_Main.designer.cs
     文件        6008  2010-07-09 04:22  RoundCaky\Frm_Main.resx
     目录           0  2011-12-22 23:11  RoundCaky\obj\
     目录           0  2013-05-09 18:00  RoundCaky\obj\Debug\
     文件         789  2013-05-09 18:00  RoundCaky\obj\Debug\DesignTimeResolveAssemblyReferences.cache
     文件        7146  2013-05-09 17:39  RoundCaky\obj\Debug\DesignTimeResolveAssemblyReferencesInput.cache
     目录           0  2011-12-22 23:11  RoundCaky\obj\Debug\Refactor\
     文件        4099  2013-05-09 17:59  RoundCaky\obj\Debug\RoundCaky.csproj.FileListAbsolute.txt
     文件         850  2013-05-09 17:59  RoundCaky\obj\Debug\RoundCaky.csproj.GenerateResource.Cache
     文件       11264  2013-05-09 17:59  RoundCaky\obj\Debug\RoundCaky.exe
     文件         180  2013-05-09 17:59  RoundCaky\obj\Debug\RoundCaky.Frm_Main.resources
     文件       26112  2013-05-09 17:59  RoundCaky\obj\Debug\RoundCaky.pdb
     文件         180  2013-05-09 17:59  RoundCaky\obj\Debug\RoundCaky.Properties.Resources.resources
     目录           0  2013-05-09 18:00  RoundCaky\obj\Debug\TempPE\
     文件        4608  2013-05-09 18:00  RoundCaky\obj\Debug\TempPE\Properties.Resources.Designer.cs.dll
     文件        3342  2010-07-09 04:19  RoundCaky\obj\Debug\制作一个可以旋转的饼型图.csproj.FileListAbsolute.txt
     文件         493  2010-07-09 04:22  RoundCaky\Program.cs
     目录           0  2011-12-22 23:11  RoundCaky\Properties\
     文件        1350  2010-07-09 04:21  RoundCaky\Properties\AssemblyInfo.cs
     文件        2858  2013-05-09 17:39  RoundCaky\Properties\Resources.Designer.cs
     文件        5612  2009-02-16 16:31  RoundCaky\Properties\Resources.resx
     文件        1109  2013-05-09 17:39  RoundCaky\Properties\Settings.Designer.cs
     文件         249  2009-02-16 16:31  RoundCaky\Properties\Settings.settings
............此处省略2个文件信息