如何在 python 中将 SHGetFileInfo 与 SHGFI_PIDL 一起使用

How to use SHGetFileInfo with SHGFI_PIDL in python

我正在尝试使用 SHGetFileInfo 检索文件信息(特别是关于图标的信息)。实际上,我没有文件的完整路径,我只有 pidl。

下面的代码 returns (0L, (0, 0, 0, '', '')) 我的问题是为什么。

from win32com.shell import shell, shellcon
def get_info():
    desktop = shell.SHGetDesktopFolder()
    eaten, desktop_pidl, attr = desktop.ParseDisplayName(None, None, r"C:\Users\Ella\Desktop")
    return shell.SHGetFileInfo(desktop_pidl, 0, shellcon.SHGFI_PIDL | shellcon.SHGFI_SYSICONINDEX | shellcon.SHGFI_ICON | shellcon.SHGFI_DISPLAYNAME)

另一方面,由于某些原因,下面的代码确实有效(它使用完整路径而不是 pidl):

from win32com.shell import shell, shellcon
def get_info2():
    return shell.SHGetFileInfo(r"C:\Users\Ella\Desktop", 0, shellcon.SHGFI_SYSICONINDEX | shellcon.SHGFI_ICON | shellcon.SHGFI_DISPLAYNAME)

谢谢!

您在 PySHGetFileInfo 中发现了一个错误。如果在 flags 中设置 SHGFI_PIDL,它会调用 PyObject_AsPIDL 并将结果存储到 pidl_or_name,但它错误地将 name 传递给了 SHGetFileInfo,在这种情况下是初始 NULL 值。请参阅下面的更多细节。

您询问如何在 shell32!SHGetFileInfoW 上设置断点。对此没有简单的答案。相反,请允许我分享一下我为测试它所做的工作的概述。希望这至少能让你入门。

测试环境:

设置 shell 环境。

"C:\Program Files\Microsoft SDKs\Windows\v7.1\Bin\SetEnv.Cmd"
set MSSdk=%WindowsSDKDir%
set SYMDIR=C:\Symbols
set SYMSRV=http://msdl.microsoft.com/download/symbols    
set _NT_SYMBOL_PATH=symsrv*symsrv.dll*%SYMDIR%*%SYMSRV%
path C:\Program Files\Debugging Tools for Windows (x64);%PATH%
path C:\Program Files\Mercurial;%PATH%

创建一个Python 虚拟环境。

py -3.4 -m venv --symlinks test

venv 没有 link .pdb 文件,因此请在 for 循环中手动获取这些文件。

set PYDIR="%ProgramW6432%\Python34"
set CMD=mklink "test\Scripts\%~nxf" "%f"
for /R %PYDIR% %f in (*.pdb) do @%CMD%

激活虚拟环境。

test\Scripts\activate

克隆 PyWin32 存储库。构建并安装版本 219。

set HGSRV=http://pywin32.hg.sourceforge.net
hg clone %HGSRV%/hgroot/pywin32/pywin32
cd pywin32
hg up b219

I edited setup.py to comment out everything related to building win32com.mapi. My setup didn't even have the required headers, and when I obtained them there were problems building the extension for WIN64.

构建并安装包。

python setup3.py install

运行 Python 在控制台调试器下,cdb.exe。

>cdb -xi ld python

Microsoft (R) Windows Debugger Version 6.12.0002.633 AMD64
Copyright (c) Microsoft Corporation. All rights reserved.

CommandLine: python
Symbol search path is: symsrv*symsrv.dll*C:\Symbols*
                       http://msdl.microsoft.com/download/symbols
Executable search path is:
(d50.1174): Break instruction exception - code 80000003 (first chance)
ntdll!LdrpDoDebuggerBreak+0x30:
00000000`770bcb70 cc              int     3
0:000> bp shell32!SHGetFileInfoW
0:000> g
Python 3.4.2 (v3.4.2:ab2c023a9432, Oct  6 2014, 22:16:31)
[MSC v.1600 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.

上面命令行中的选项-xi ld设置了一个过滤器来忽略打印加载的模块。有很多教程和 'cheat sheets' 在线使用 Microsoft 的调试器,如 WinDbg、cdb 和 kd。调试器都使用相同的引擎,因此它们支持一组通用的调试命令。

附加的调试器在 shell32!SHGetFileInfoW 上设置了一个断点。当断点被触发时,调试器会获取控制台。 Windows 控制台的少数可取之处之一是其每个应用程序的输入历史记录和别名。这使得在同一个控制台中跳进和跳出调试器和被调试器时调用命令变得很方便 window.

>>> import os
>>> from win32com.shell import shell, shellcon
>>> print(shell.__file__)
C:\Temp\test\lib\site-packages\win32comext\shell\shell.pyd
>>> path = os.path.expanduser(r'~\Desktop\desktop.ini')
>>> pidl = shell.SHParseDisplayName(path, 0, None)[0]
>>> flags = (shellcon.SHGFI_PIDL |
...          shellcon.SHGFI_SYSICONINDEX |
...          shellcon.SHGFI_ICON |
...          shellcon.SHGFI_DISPLAYNAME)
>>> shell.SHGetFileInfo(pidl, 0, flags)
Breakpoint 0 hit
SHELL32!SHGetFileInfoW:
000007fe`fd692290 fff3            push    rbx
0:000> k 5
*** WARNING: Unable to verify checksum for
C:\Temp\test\lib\site-packages\win32comext\shell\shell.pyd
Child-SP          RetAddr           Call Site
00000000`003ff2d8 00000000`5f44c5e8 SHELL32!SHGetFileInfoW
00000000`003ff2e0 00000000`5f5af8bd shell!PySHGetFileInfo+0xf8
00000000`003ff610 00000000`5f62385b python34!PyCFunction_Call+0x12d
00000000`003ff640 00000000`5f625c89 python34!call_function+0x2ab
00000000`003ff6a0 00000000`5f62770c python34!PyEval_EvalFrameEx+0x2279
0:000> r rcx
rcx=0000000000000000
0:000> g
(0, (0, 0, 0, '', ''))

在 Windows x64 ABI 中,函数的第一个参数在寄存器 rcx 中传递。我们从SHGetFileInfo docs that this should be the PIDL, but actually NULL is being passed. Clearly this is a bug. The stack trace lays the blame on shell!PySHGetFileInfo知道。这是有问题的代码片段:

    if (flags & SHGFI_PIDL) {
        ok = PyObject_AsPIDL(obName, &pidl, FALSE);
        pidl_or_name = (TCHAR *)pidl;
    } else {
        ok = PyWinObject_AsTCHAR(obName, &name, FALSE);
        pidl_or_name = name;
    }
    if (!ok)
        return NULL;
    SHFILEINFO info;
    memset(&info, 0, sizeof(info));
    info.dwAttributes = info_attrs;
    PY_INTERFACE_PRECALL;
    DWORD_PTR dw = SHGetFileInfo(name, attr, &info, sizeof(info), flags);

错误是将 name 作为第一个参数传递,而不是 pidl_or_name


问题已标记为 ctypes。 IMO,如果使用 ctypes 消除了诸如 PyWin32 之类的大量依赖项,那么使用 ctypes 是值得的。对于基于 COM 的 API,我通常不会单独使用 ctypes。如果你想尝试的话,comtypes 包建立在 ctypes 之上。在这种情况下,可以通过调用 SHParseDisplayName 来避免直接调用 COM 方法。除了使用 HRESULT return 代码外,它与任何其他 Win32 API 非常相似。

import types as _types
import ctypes as _ctypes
from ctypes import wintypes as _wtypes
_mtypes = _types.ModuleType('_mtypes')

_ole32 = _ctypes.WinDLL('ole32')
_shell32 = _ctypes.WinDLL('shell32')
_user32 = _ctypes.WinDLL('user32')

try:
    from win32com.shell import shell as _shell
except ImportError:
    _shell = None

try:
    from win32com.shell import shellcon
except ImportError:
    shellcon = _types.ModuleType('shellcon')
    shellcon.SHGFI_LARGEICON         = 0x00000
    shellcon.SHGFI_SMALLICON         = 0x00001
    shellcon.SHGFI_OPENICON          = 0x00002
    shellcon.SHGFI_SHELLICONSIZE     = 0x00004
    shellcon.SHGFI_PIDL              = 0x00008
    shellcon.SHGFI_USEFILEATTRIBUTES = 0x00010
    shellcon.SHGFI_ICON              = 0x00100
    shellcon.SHGFI_DISPLAYNAME       = 0x00200
    shellcon.SHGFI_TYPENAME          = 0x00400
    shellcon.SHGFI_ATTRIBUTES        = 0x00800
    shellcon.SHGFI_ICONLOCATION      = 0x01000
    shellcon.SHGFI_EXETYPE           = 0x02000
    shellcon.SHGFI_SYSICONINDEX      = 0x04000
    shellcon.SHGFI_LINKOVERLAY       = 0x08000
    shellcon.SHGFI_SELECTED          = 0x10000
    shellcon.SHGFI_ATTR_SPECIFIED    = 0x20000

try:
    import win32con
except ImportError:
    win32con = _types.ModuleType('win32con')
    win32con.MAX_PATH = 260
    win32con.FILE_ATTRIBUTE_READONLY            = 0x00001
    win32con.FILE_ATTRIBUTE_HIDDEN              = 0x00002
    win32con.FILE_ATTRIBUTE_SYSTEM              = 0x00004
    win32con.FILE_ATTRIBUTE_DIRECTORY           = 0x00010
    win32con.FILE_ATTRIBUTE_ARCHIVE             = 0x00020
    win32con.FILE_ATTRIBUTE_DEVICE              = 0x00040
    win32con.FILE_ATTRIBUTE_NORMAL              = 0x00080
    win32con.FILE_ATTRIBUTE_TEMPORARY           = 0x00100
    win32con.FILE_ATTRIBUTE_ATOMIC_WRITE        = 0x00200
    win32con.FILE_ATTRIBUTE_SPARSE_FILE         = 0x00200
    win32con.FILE_ATTRIBUTE_REPARSE_POINT       = 0x00400
    win32con.FILE_ATTRIBUTE_XACTION_WRITE       = 0x00400
    win32con.FILE_ATTRIBUTE_COMPRESSED          = 0x00800
    win32con.FILE_ATTRIBUTE_OFFLINE             = 0x01000
    win32con.FILE_ATTRIBUTE_NOT_CONTENT_INDEXED = 0x02000
    win32con.FILE_ATTRIBUTE_ENCRYPTED           = 0x04000
    win32con.FILE_ATTRIBUTE_VIRTUAL             = 0x10000

_mtypes.CData = _ctypes.Array.__bases__[0]
_mtypes.PPIDLIST_ABSOLUTE = _ctypes.POINTER(_ctypes.c_void_p)
_mtypes.SFGAOF = _wtypes.ULONG
_mtypes.PSFGAOF = _ctypes.POINTER(_mtypes.SFGAOF)

_ole32.CoInitialize.restype = _ctypes.HRESULT # checked
_ole32.CoInitialize.argtypes = (_ctypes.c_void_p,)
_ole32.CoUninitialize.restype = None
_ole32.CoUninitialize.argtypes = ()
_ole32.CoTaskMemFree.restype = None
_ole32.CoTaskMemFree.argtypes = (_ctypes.c_void_p,)
_user32.DestroyIcon.argtypes = (_wtypes.HICON,)

_shell32.SHParseDisplayName.restype = _ctypes.HRESULT # checked
_shell32.SHParseDisplayName.argtypes = (
    _wtypes.LPCWSTR,           # pszName,   _In_
    _ctypes.c_void_p,          # pbc,       _In_opt_
    _mtypes.PPIDLIST_ABSOLUTE, # ppidl,     _Out_
    _mtypes.SFGAOF,            # sfgaoIn,   _In_
    _mtypes.PSFGAOF)           # psfgaoOut, _Out_opt_

class SHFILEINFO(_ctypes.Structure):
   _fields_ = (('hIcon', _wtypes.HICON),
               ('iIcon', _ctypes.c_int),
               ('dwAttributes', _wtypes.DWORD),
               ('szDisplayName', _wtypes.WCHAR * win32con.MAX_PATH),
               ('szTypeName', _wtypes.WCHAR * 80))

_mtypes.SHFILEINFO = SHFILEINFO
_mtypes.PSHFILEINFO = _ctypes.POINTER(SHFILEINFO)

_shell32.SHGetFileInfoW.restype = _ctypes.c_void_p
_shell32.SHGetFileInfoW.argtypes = (
    _wtypes.LPVOID,      # pszPath,          _In_
    _wtypes.DWORD,       # dwFileAttributes,
    _mtypes.PSHFILEINFO, # psfi,             _Inout_
    _wtypes.UINT,        # cbFileInfo,
    _wtypes.UINT)        # uFlags

def SHGetFileInfo(pidl, attributes=0, flags=0):
    if _shell is not None:
        if not isinstance(pidl, (str, bytes, _mtypes.CData)):
            pidl = _shell.PIDLAsString(pidl)
    finfo = SHFILEINFO()
    _ole32.CoInitialize(None)    
    try:
        retval = _shell32.SHGetFileInfoW(pidl,
                                         attributes,
                                         _ctypes.byref(finfo),
                                         _ctypes.sizeof(finfo),
                                         flags)
    finally:
        _ole32.CoUninitialize()
    if not retval:            
        if flags != shellcon.SHGFI_EXETYPE:
            raise _ctypes.WinError()
    return retval, finfo

示例:

if __name__ == '__main__':
    import os    
    path = os.path.expanduser(r'~\Desktop\desktop.ini')
    pidl = _shell.SHParseDisplayName(path, 0)[0]
    assert isinstance(pidl, list)

    flags = (shellcon.SHGFI_PIDL |
             shellcon.SHGFI_ICON |
             shellcon.SHGFI_DISPLAYNAME |
             shellcon.SHGFI_TYPENAME |
             shellcon.SHGFI_ATTRIBUTES |
             shellcon.SHGFI_SYSICONINDEX)

    hImageList, finfo = SHGetFileInfo(pidl, 0, flags)

    print('hImageList:', hImageList)
    for name, typ in finfo._fields_:
        print(name, ': ', ascii(getattr(finfo, name)), sep='')

    if finfo.hIcon:
        _user32.DestroyIcon(finfo.hIcon)

输出:

hImageList: 4411024
hIcon: 10617107
iIcon: 7
dwAttributes: 1078497655
szDisplayName: 'desktop.ini'
szTypeName: 'Configuration settings'