registry.py 文件源码

def QueryValueEx(key, value_name):
    """This calls the Windows QueryValueEx function in a Unicode safe way."""
    size = 256
    data_type = ctypes.wintypes.DWORD()
    while True:
        tmp_size = ctypes.wintypes.DWORD(size)
        buf = ctypes.create_string_buffer(size)
        rc = RegQueryValueEx(key.handle, value_name, LPDWORD(),
                             ctypes.byref(data_type), ctypes.cast(buf, LPBYTE),
                             ctypes.byref(tmp_size))
        if rc != ERROR_MORE_DATA:
            break

        # We limit the size here to ~10 MB so the response doesn't get too big.
        if size > 10 * 1024 * 1024:
            raise exceptions.WindowsError("Value too big to be read.")

        size *= 2

    if rc != ERROR_SUCCESS:
        raise ctypes.WinError(2)

    return (Reg2Py(buf, tmp_size.value, data_type.value), data_type.value)