mmioOpen API有问题 [英] A problem with mmioOpen API

问题描述

我正在尝试制作一个播放.wav文件的音频播放器.我编写了一个ReadWaveFile(CString szFilename)函数，用于将文件的wave数据读取到WAVEHDR结构中.在此功能

I am trying to make an audio player that plays .wav files. I wrote a function ReadWaveFile(CString szFilename) for reading the wave data of the file into the WAVEHDR structure. In this function

<pre>
BOOL CWavePlay::ReadWaveFile(CString szFilename)
{
	hmmio = mmioOpen((LPTSTR)&szFilename,NULL,MMIO_READ);
	ASSERT(hmmio);		//error here: hmmio=0x00000000
	if(hmmio==0)
		return FALSE;
        ....
}

每当我将文件路径传递给此函数以打开指定的文件时，mmioOpen始终返回0.而且令我感到困惑的是，当我在mmioOpen API中显式传递文件路径时，代码可以工作；即返回有效的句柄.

mmioOpen is always returning 0 whenever I pass a filepath to this function for opening the specified file. And what baffles me is when i pass the filepath explicitly in mmioOpen API the code works; i.e., a valid handle is returned.
can some body explain why is this happening??

推荐答案

尝试一下-hmmio = mmioOpen((LPTSTR)szFilename,NULL,MMIO_READ);
您还可以将PlaySound API与SND_FILENAME标志一起使用.

Try this - hmmio = mmioOpen((LPTSTR)szFilename,NULL,MMIO_READ);
You could also use the PlaySound API with the SND_FILENAME flag.

解决方案是:

the solution is:

<pre>hmmio = mmioOpen((LPTSTR)(LPCTSTR)szFilename,NULL,MMIO_READ);

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