low_level.py 文件源码

def _cf_string_to_unicode(value):
    """
    Creates a Unicode string from a CFString object. Used entirely for error
    reporting.

    Yes, it annoys me quite a lot that this function is this complex.
    """
    value_as_void_p = ctypes.cast(value, ctypes.POINTER(ctypes.c_void_p))

    string = CoreFoundation.CFStringGetCStringPtr(
        value_as_void_p,
        CFConst.kCFStringEncodingUTF8
    )
    if string is None:
        buffer = ctypes.create_string_buffer(1024)
        result = CoreFoundation.CFStringGetCString(
            value_as_void_p,
            buffer,
            1024,
            CFConst.kCFStringEncodingUTF8
        )
        if not result:
            raise OSError('Error copying C string from CFStringRef')
        string = buffer.value
    if string is not None:
        string = string.decode('utf-8')
    return string