[DllImport("WinMm.dll",CharSet = CharSet.Auto,CallingConvention = CallingConvention.Cdecl)]
public static extern int mciSendString(string lpstrCommand,string lpstrReturnString,int uReturnLength,IntPtr hwndCallback);

string path = Guid.NewGuid() + ".wav";

//开始录音
mciSendString("set wave bitpersample 8","",0,IntPtr.Zero);
 mciSendString("set wave samplespersec 20000","",0,IntPtr.Zero);
 mciSendString("set wave channels 2","",0,IntPtr.Zero);
 mciSendString("set wave format tag pcm","",0,IntPtr.Zero);
 mciSendString("open new type WAVEAudio alias movie","",0,IntPtr.Zero);//这个决定是wav文件
mciSendString("record movie","",0,IntPtr.Zero);

//保存录音
mciSendString("stop movie","",0,IntPtr.Zero);
mciSendString($"save movie {path}","",0,IntPtr.Zero);//换成wav有效 换成mp3文件错误
mciSendString("close movie","",0,IntPtr.Zero);

 //播放
string s = $"open \"{path}\" alias media";

mciSendString("close all",null,0,IntPtr.Zero);

mciSendString(s,null,0,IntPtr.Zero);

mciSendString("set media time format milliseconds",null,0,IntPtr.Zero);

mciSendString("play media",null,0,IntPtr.Zero);

mciSendString("play media notify",null,0,this.Handle);//必须加当前窗体句柄才能 触发 DefWndProc 的 条件 m.Msg == 0x3B9

protected override void DefWndProc(ref Message m) {
    base.DefWndProc(ref m);
    if (m.Msg == 0x3B9) {
     Text = "播放已完成...";
     }

}