visual-c++ - 如何更改某些文件类型的图标？

Question

我有 IconHandler 来更改某些文件的图标。但其他文件图标变为空白。如何为其他文件保留默认图标？

 HRESULT CSimpleShlExt::GetIconLocation(UINT uFlags,
  PTSTR pszIconFile,
  UINT cchMax,
  int *piIndex,
  UINT *pwFlags)
 { 
    if (condition)){
        // works well
        lstrcpyn(pszIconFile, L"C:\\Windows\\System32\\shell32.dll", cchMax);
        *piIndex = 5;
        *pwFlags = 0;
    } else {
        // blank icon :(
        *pwFlags = GIL_PERINSTANCE | GIL_NOTFILENAME;// | GIL_DONTCACHE ;
    }
    return S_OK;
 }

这是我的 .rgs 文件:

HKCR  
{
    NoRemove CLSID
{
    ForceRemove {B70B7A24-5180-4092-B3BA-6266F914C053} = s 'My Shell Extension'
    {
        InprocServer32 = s '%MODULE%'
        {
            val ThreadingModel = s 'Apartment'
        }
        TypeLib = s '{62C6D1EB-C172-4E05-BFD2-5F9313832CC3}'
        Version = s '1.0'
    }
}
    NoRemove txtfile
    {
        NoRemove ShellEx
        {
            ForceRemove IconHandler = s '{B70B7A24-5180-4092-B3BA-6266F914C053}'
        }
    }
}

Answer 1

此代码有效:

 HRESULT CSimpleShlExt::GetIconLocation(UINT uFlags,
 PTSTR pszIconFile,
 UINT cchMax,
 int *piIndex,
 UINT *pwFlags)
 { 

    if (condition))
    {
        lstrcpyn(pszIconFile, L"C:\\Windows\\System32\\Test.dll", cchMax);

        *piIndex = 0;
    } 
    else 
    {
        *piIndex = 1;

    }

    *pwFlags = 0;
    return S_OK;

 }

HRESULT CSimpleShlExt::Extract(
LPCTSTR pszFile,
UINT nIconIndex,
HICON *phiconLarge,
HICON *phiconSmall,
UINT nIconSize)
{
    return S_FALSE;
}

更改的 .rgs 文件:

HKCR  
{
    NoRemove CLSID
{
    ForceRemove {B70B7A24-5180-4092-B3BA-6266F914C053} = s 'My Shell Extension'
    {
        InprocServer32 = s '%MODULE%'
        {
            val ThreadingModel = s 'Apartment'
        }
        TypeLib = s '{62C6D1EB-C172-4E05-BFD2-5F9313832CC3}'
        Version = s '1.0'
    }
}
    NoRemove txtfile
    {
        NoRemove DefaultIcon = s '%%1'
        NoRemove ShellEx
        {
            ForceRemove IconHandler = s '{B70B7A24-5180-4092-B3BA-6266F914C053}'
        }
    }
}

来自“MSDN”- How to Create Icon Handlers :

Registering Icon Handlers

When you statically register an icon for a file type, you create a DefaultIcon subkey under the ProgID for the file type. Its default value is set to the file that contains the icon. To register an icon handler, you must still have the DefaultIcon subkey, but its default value must be set to "%1".