一、using System.Runtime.InteropServices;
二、[DllImport("Shell32.dll")]
         public static extern int ExtractIcon(IntPtr hInst, string strFileName, int nIconIndex);
         [DllImport("Shell32.dll")]
         public static extern int SHGetFileInfo(string pszPath, uint dwFileAttributes, ref Fileinfos psfi, uint cbFileInfo, uint uFlags);

public struct Fileinfos
         {
             public IntPtr hIcon;
             public int iIcon;
             public uint dwAttributes;
             public char szDisplayName;
             public char szTypeName;
         }

/// <summary>
         /// 设置图标,把得到的图标放入一个ImageList
         /// </summary>
         /// <param name="imageList">ImageList,可以new一个</param>
         /// <param name="FileName">应用程序的路径</param>
         /// <param name="pic">图片控件名</param>
         /// <param name="tf">不了解</param>
         private void SetIcon(ImageList imageList, string FileName,System.Windows.Forms.PictureBox pic, bool tf)
         {
             Fileinfos fi = new Fileinfos();
             if (tf == true)
             {
                 int iTotal = (int)SHGetFileInfo(FileName, 0, ref fi, 100, 16640);
                 try
                 {
                     if (iTotal > 0)
                     {
                         Icon ic = Icon.FromHandle(fi.hIcon);
                         imageList.Images.Add(ic);//添加到ImageList,可放图标和图片，只做一个转换用
                         pic.Image=imageList.Images[0];//把图标取出来
                     }
                 }
                 catch (Exception ex)
                 {
                     MessageBox.Show(ex.Message, "错误提示", 0, MessageBoxIcon.Error);
                 }
             }
             else
             {
                 int iTotal = (int)SHGetFileInfo(FileName, 0, ref fi, 100, 257);
                 try
                 {
                     if (iTotal > 0)
                     {
                         Icon ic = Icon.FromHandle(fi.hIcon);
                         imageList.Images.Add(ic);//添加到ImageList,可放图标和图片，只做一个转换用
                         pictureBox1.Image = imageList.Images[0];//把图标取出来
                     }
                 }
                 catch (Exception ex)
                 {
                     MessageBox.Show(ex.Message, "错误提示", 0, MessageBoxIcon.Error);
                 }
             }
         }

/// <summary>
         /// 设置图标，这里是当前窗体
         /// </summary>
         /// <param name="FileName">应用程序的路径</param>
         /// <param name="tf">不知道什么意思</param>
         private void SetFormIcon(string FileName, bool tf)
         {
             Fileinfos fi = new Fileinfos();
             if (tf == true)
             {
                 int iTotal = (int)SHGetFileInfo(FileName, 0, ref fi, 100, 16640);
                 try
                 {
                     if (iTotal > 0)
                     {
                         Icon ic = Icon.FromHandle(fi.hIcon);
                         this.Icon = ic;
                     }
                 }
                 catch (Exception ex)
                 {
                     MessageBox.Show(ex.Message, "错误提示", 0, MessageBoxIcon.Error);
                 }
             }
             else
             {
                 int iTotal = (int)SHGetFileInfo(FileName, 0, ref fi, 100, 257);
                 try
                 {
                     if (iTotal > 0)
                     {
                         Icon ic = Icon.FromHandle(fi.hIcon);
                         this.Icon = ic;
                     }
                 }
                 catch (Exception ex)
                 {
                     MessageBox.Show(ex.Message, "错误提示", 0, MessageBoxIcon.Error);
                 }
             }
         }