python - 如何使用unicode版本Windows API : mciSendString(), Python

Question

我正在 Windows 10 上测试 Python 包:playsound

路径名的某些字符似乎有问题，例如“c:\sauté”和宽字符。所以它找不到文件。

Error 275 for command: open "C:\sauté.wav" alias playsound_0.4091468603477375 Cannot find the specified file. Make sure the path and filename are correct.

我尝试使用 unicode 版本mciSendStringW()。事实证明 mciSendStringW 根本无法识别编码的命令。我不知道现在还能做什么。

def winCommand(*command):
    buf = c_buffer(255)
    command = ' '.join(command).encode(getfilesystemencoding())
    errorCode = int(windll.winmm.mciSendStringA(command, buf, 254, 0))
    if errorCode:
        errorBuffer = c_buffer(255)
        windll.winmm.mciGetErrorStringA(errorCode, errorBuffer, 254)
        exceptionMessage = ('\n    Error ' + str(errorCode) + ' for command:'
                            '\n        ' + command.decode() +
                            '\n    ' + errorBuffer.value.decode())
        raise PlaysoundException(exceptionMessage)
    return buf.value

项目站点:https://pypi.org/project/playsound/ (包括安装和快速入门指南)

源代码:https://raw.githubusercontent.com/TaylorSMarks/playsound/master/playsound.py

微软mciSendString函数: https://learn.microsoft.com/en-us/previous-versions/dd757161(v=vs.85)

Answer 1

使用 Wide 函数 mciSendStringW 时，不应对字符串进行编码。因此，您的行应该简单地读取 command = ' '.join(command)。至少在我使用 Python 3.6 的 Windows10 机器上是这样。

要仔细检查，您可以运行下面的代码。第二个错误代码为 296，这只是提示文件类型错误，因为我们创建了一个空文件进行测试。

from ctypes import c_buffer, windll
from sys import getfilesystemencoding

if __name__ == '__main__':
    buf = c_buffer(255)
    filesystemencoding = getfilesystemencoding()
    filename = r'.\sauté.wav'
    # create the file if it doesn't exist
    file = open(filename, 'w+')
    file.close()

    # ASCII
    command = 'open ' + filename
    byte_string_command = command.encode(filesystemencoding)

    errorCode = int(windll.winmm.mciSendStringA(byte_string_command, buf, 254, 0))
    # errorCode should be 275: Cannot find the file
    errorBuffer = c_buffer(255)
    windll.winmm.mciGetErrorStringA(errorCode, errorBuffer, 254)
    print("{}: {}".format(errorCode, errorBuffer.value.decode()))

    # Unicode
    errorCode = int(windll.winmm.mciSendStringW(command, buf, 254, 0))
    # errorCode should be 296: The specified file cannot be played
    errorBuffer = c_buffer(255)
    windll.winmm.mciGetErrorStringA(errorCode, errorBuffer, 254)
    print("{}: {}".format(errorCode, errorBuffer.value.decode()))