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此示例在 python 3.3.2 文档中：

http://docs.python.org/3/library/ctypes.html?highlight=ctypes#ctypes

但是：当我在解释器中尝试时，我得到一个错误。

我使用 windows7 32 python 3.3.2。

请帮忙。

from ctypes import c_int, WINFUNCTYPE, windll
from ctypes.wintypes import HWND, LPCSTR, UINT
prototype = WINFUNCTYPE(c_int, HWND, LPCSTR, LPCSTR, UINT)
paramflags = (1, "hwnd", 0), (1, "text", "Hi"), (1, "caption", None), (1, "flags", 0)
MessageBox = prototype(("MessageBoxA", windll.user32), paramflags)
MessageBox()
MessageBox(text="Spam, spam, spam")
MessageBox(flags=2, text="foo bar")

error message:
Traceback (most recent call last):
File "<string>", line 250, in run_nodebug
File "<g1>", line 7, in <module>
ctypes.ArgumentError: argument 2: <class 'TypeError'>: wrong type
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1 回答 1

6

猜猜这是文档中的错误。;-)

在 Python 3 中，默认情况下所有字符串都是 Unicode，但该示例调用的是 ANSIMessageBoxA函数，而不是MessageBoxWUnicode 版本。见16.17.1.2。ctypes从文档中加载的 dll 访问函数。

因此，MessageBoxA在示例中，您可以通过调用将函数的输入字符串参数编码为所需的内容来使其工作locale.getpreferredencoding()：

from ctypes import c_int, WINFUNCTYPE, windll
from ctypes.wintypes import HWND, LPCSTR, UINT
import locale
preferred_encoding = locale.getpreferredencoding(False)
prototype = WINFUNCTYPE(c_int, HWND, LPCSTR, LPCSTR, UINT)
paramflags = ((1, "hwnd", 0), (1, "text", "Hi".encode(preferred_encoding)),
                (1, "caption", None), (1, "flags", 0))
MessageBox = prototype(("MessageBoxA", windll.user32), paramflags)

MessageBox()
MessageBox(text="Spam, spam, spam".encode(preferred_encoding))
MessageBox(flags=2, text="foo bar".encode(preferred_encoding))

MessageBoxW使用支持“宽”Unicode 字符串参数（LPCWSTR而不是）的 Windows 函数会少很多尴尬，这LPCSTR使得几乎每次调用都不需要对它们进行显式编码。此外，我会用命名常量替换示例中的大部分“幻数”：

from ctypes import c_int, WINFUNCTYPE, windll
from ctypes.wintypes import HWND, LPCWSTR, UINT
import win32con  # contains Win32 constants pulled from the C header files
INPUT_PARM, OUTPUT_PARAM, INPUT_PARM_DEFAULT_ZERO = 1, 2, 4
prototype = WINFUNCTYPE(c_int, HWND, LPCWSTR, LPCWSTR, UINT)
paramflags = ((INPUT_PARM, "hwnd", 0),
              (INPUT_PARM, "text", "Hi"),
              (INPUT_PARM, "caption", None),
              (INPUT_PARM, "flags", win32con.MB_HELP))
MessageBox = prototype(("MessageBoxW", windll.user32), paramflags)

MessageBox()
MessageBox(text="Spam, spam, spam")
MessageBox(flags=win32con.MB_ABORTRETRYIGNORE, text="foo bar")
于 2013-08-10T18:49:15.973 回答