[System.Runtime.InteropServices.DllImport("shell32.dll")]
      private static extern int ExtractIconEx(string lpszFile, int niconIndex, IntPtr []phiconLarge,IntPtr []phiconSmall, int nIcons);
 
       private IntPtr[] largeIcons, smallIcons ;  //存放大/小图标的指针数组
 
       private string appPath = @"D:\Program Files\Tencent\QQ\Bin\QQ.exe";
 
      //第一步：获取程序中的图标数
      
      int IconCount = ExtractIconEx(appPath, -1, null,null, 0); 
    
     //第二步：创建存放大/小图标的空间
 
      largeIcons = new IntPtr[IconCount];
     
      smallIcons = new IntPtr[IconCount];
 
     //第三步：抽取所有的大小图标保存到largeIcons和smallIcons中
      
      ExtractIconEx(appPath, 0, largeIcons,smallIcons, IconCount);
     
     //第四步：显示抽取的图标(推荐使用imageList和listview搭配显示）
 
      for (int i = 0; i < IconCount; i++)
      {
            this.imageList1.Images.Add(Icon.FromHandle(largeIcons[i])); //图标添加进imageList中
 
            ListViewItem lvi = new ListViewItem();
 
            lvi.ImageIndex = i;  //listview子项图标索引项
 
            this.listview1.Items.Add(lvi);
      }
 
      //第五步：保存图标
       
       for (int i = 0; i < this.listview1.Items.Count; i++)
       {
            System.IO.FileStream fs = new System.IO.FileStream(Application.StartupPath +"\\newIcon.png", System.IO.FileMode.Create);
 
            this.imageList1.Images[this.listview1.Items[i].ImageIndex].Save(fs, System.Drawing.Imaging.ImageFormat.Png);
 
            fs.Close();
       }