C#簡単なmp 3再生を実現する方法

/// 

///  
/// 
class TestDemo
{
 public void Test()
 {
  clsMCI cm = new clsMCI();
  cm.FileName = "alarm.mp3";
  cm.play();
 }
}
/// 

/// clsMci  。
/// 
public class clsMCI
{
 public clsMCI()
 {
 }
 // API  
 [MarshalAs(UnmanagedType.ByValTStr,SizeConst=260)]
 private string Name = "" ;
 [MarshalAs(UnmanagedType.ByValTStr,SizeConst=128)]
 private string durLength = "" ;
 [MarshalAs(UnmanagedType.LPTStr,SizeConst=128)]
 private string TemStr ="";
 int ilong;
 // 
 public enum State
 {
  mPlaying = 1,
  mPuase = 2,
  mStop = 3
 };
 // 
 public struct structMCI 
 {
  public bool bMut;
  public int iDur;
  public int iPos;
  public int iVol;
  public int iBal;
  public string iName;
  public State state;
 };
 public structMCI mc =new structMCI() ;
 // 
 public string FileName
 {
  get
  {
  return mc.iName;
  }
  set
  {
　　　　try
    {
     TemStr =""; 
     TemStr = TemStr.PadLeft(127,Convert.ToChar(" "));
     Name = Name.PadLeft(260,Convert.ToChar(" ")) ;
     mc.iName = value; 
     ilong = APIClass.GetShortPathName(mc.iName,Name, Name.Length);
     Name = GetCurrPath(Name);
     Name = "open " + Convert.ToChar(34) + Name + Convert.ToChar(34) + " alias media";
     ilong = APIClass.mciSendString("close all", TemStr, TemStr.Length , 0);
     ilong = APIClass.mciSendString( Name, TemStr, TemStr.Length, 0);
     ilong = APIClass.mciSendString("set media time format milliseconds", TemStr, TemStr.Length , 0);
     mc.state = State.mStop; 
    }
    catch
    {
    }
  }
 }
 // 
 public void play()
 {
  TemStr = "";
  TemStr = TemStr.PadLeft(127,Convert.ToChar(" "));
  APIClass.mciSendString("play media", TemStr, TemStr.Length , 0);
  mc.state = State.mPlaying ;
 }
 // 
 public void StopT()
 {
  TemStr = "";
  TemStr = TemStr.PadLeft(128,Convert.ToChar(" "));
  ilong = APIClass.mciSendString("close media", TemStr, 128, 0);
  ilong = APIClass.mciSendString("close all", TemStr, 128, 0);
  mc.state = State.mStop ; 
 }
 public void Puase()
 {
  TemStr = "";
  TemStr = TemStr.PadLeft(128,Convert.ToChar(" "));
  ilong = APIClass.mciSendString("pause media", TemStr, TemStr.Length, 0);
  mc.state = State.mPuase ; 
 }
 private string GetCurrPath(string name)
 {
  if(name.Length <1) return ""; 
  name = name.Trim();
  name = name.Substring(0,name.Length-1);
  return name;
 }
 // 
 public int Duration
 {
  get
  {
   durLength = "";
   durLength = durLength.PadLeft(128,Convert.ToChar(" ")) ;
   APIClass.mciSendString("status media length", durLength, durLength.Length, 0);
   durLength = durLength.Trim();
   if(durLength == "") return 0;
   return (int)(Convert.ToDouble(durLength) / 1000f); 
  }
 }
 // 
 public int CurrentPosition
 {
  get
  {
   durLength = "";
   durLength = durLength.PadLeft(128,Convert.ToChar(" ")) ;
   APIClass.mciSendString("status media position", durLength, durLength.Length, 0);
   mc.iPos = (int)(Convert.ToDouble(durLength) / 1000f);
   return mc.iPos;
  }
 }
}
public class APIClass
{
  [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
  public static extern int GetShortPathName (
   string lpszLongPath,
   string shortFile,
   int cchBuffer
);
[DllImport("winmm.dll", EntryPoint="mciSendString", CharSet = CharSet.Auto)]
public static extern int mciSendString (
   string lpstrCommand,
   string lpstrReturnString,
   int uReturnLength,
   int hwndCallback
  );
}