如何用简单的办法根据文件名和扩展名获得该文件的图标

Question

using System;
using System.Runtime.InteropServices;
using System.Drawing;namespace test
{
/// <summary>
/// Summary description for ExtractIcon.
/// </summary>
public class ExtractIcon
{
[DllImport("Shell32.dll")]
private static extern int  SHGetFileInfo
(
string pszPath,
uint dwFileAttributes,
out SHFILEINFO psfi,
uint cbfileInfo,
SHGFI uFlags
); [StructLayout(LayoutKind.Sequential)]
private struct SHFILEINFO
{
public SHFILEINFO(bool b)
{
hIcon=IntPtr.Zero;iIcon=0;dwAttributes=0;szDisplayName="";szTypeName="";
}
public IntPtr hIcon;
public int iIcon;
public uint dwAttributes;
[MarshalAs(UnmanagedType.LPStr, SizeConst=260)]
public string szDisplayName;
[MarshalAs(UnmanagedType.LPStr, SizeConst=80)]
public string szTypeName;
}; private ExtractIcon()
{
} private enum SHGFI
{
SmallIcon   = 0x00000001,
LargeIcon   = 0x00000000,
Icon    = 0x00000100,
DisplayName   = 0x00000200,
Typename   = 0x00000400,
SysIconIndex  = 0x00004000,
UseFileAttributes = 0x00000010
} /// <summary>
/// Get the associated Icon for a file or application, this method always returns
/// an icon.  If the strPath is invalid or there is no idonc the default icon is returned
/// </summary>
/// <param name="strPath">full path to the file</param>
/// <param name="bSmall">if true, the 16x16 icon is returned otherwise the 32x32</param>
/// <returns></returns>
public static Icon GetIcon(string strPath, bool bSmall)
{
SHFILEINFO info = new SHFILEINFO(true);
int cbFileInfo = Marshal.SizeOf(info);
SHGFI flags;
if (bSmall)
flags = SHGFI.Icon|SHGFI.SmallIcon|SHGFI.UseFileAttributes;
else
flags = SHGFI.Icon|SHGFI.LargeIcon|SHGFI.UseFileAttributes; SHGetFileInfo(strPath, 256, out info,(uint)cbFileInfo, flags);
return Icon.FromHandle(info.hIcon);
}
}
}

Answer 1

核心代码：
using System;
using System.Runtime.InteropServices;
using System.Drawing;
namespace WindowsAppTmp
{
 public class ExtractIcon
 {
  [DllImport("Shell32.dll")]
  private static extern int  SHGetFileInfo
   (
   string pszPath,
   uint dwFileAttributes,
   out SHFILEINFO psfi,
   uint cbfileInfo,
   SHGFI uFlags
   );  [StructLayout(LayoutKind.Sequential)]
   private struct SHFILEINFO
  {
   public SHFILEINFO(bool b)
   {
    hIcon=IntPtr.Zero;iIcon=0;dwAttributes=0;szDisplayName="";szTypeName="";
   }
   public IntPtr hIcon;
   public int iIcon;
   public uint dwAttributes;
   [MarshalAs(UnmanagedType.LPStr, SizeConst=260)]
   public string szDisplayName;
   [MarshalAs(UnmanagedType.LPStr, SizeConst=80)]
   public string szTypeName;
  };  private ExtractIcon()
  {
  }  private enum SHGFI
  {
   SmallIcon   = 0x00000001,
   LargeIcon   = 0x00000000,
   Icon    = 0x00000100,
   DisplayName   = 0x00000200,
   Typename   = 0x00000400,
   SysIconIndex  = 0x00004000,
   UseFileAttributes = 0x00000010
  }
  public static Icon GetIcon(string strPath, bool bSmall)
  {
   SHFILEINFO info = new SHFILEINFO(true);
   int cbFileInfo = Marshal.SizeOf(info);
   SHGFI flags;
   if (bSmall)
    flags = SHGFI.Icon|SHGFI.SmallIcon|SHGFI.UseFileAttributes;
   else
    flags = SHGFI.Icon|SHGFI.LargeIcon|SHGFI.UseFileAttributes;   SHGetFileInfo(strPath, 256, out info,(uint)cbFileInfo, flags);
   return Icon.FromHandle(info.hIcon);
  }
 }
}

Answer 2

http://www.codeproject.com/csharp/fileicon.asp?target=icon