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C#中用API实现MP3等音频文件的播放类

时间:08-14 来源:中国测控网 点击:
C#没有提供播放MP3等音频文件的类,要编写播放MP3等音频文件程序,必须使用第三方控件或类。本文使用API函数mciSendString,编写一个播放MP3等音频文件的类。

具体源码如下:

一、使用API函数mciSendString构成的媒体播放类。

using System;

using System.Runtime.InteropServices;

using System.Text;

using System.IO ;

namespace clsMCIPlay

{

  ///

  /// clsMci 的摘要说明。

  ///

  public class clsMCI

  {

public clsMCI()

{

  //

  // TODO: 在此处添加构造函数逻辑

  //

}

//定义API函数使用的字符串变量

[MarshalAs(Unmana
gedType.ByValTStr,SizeConst=260)]

private string Name = "" ;

[MarshalAs(UnmanagedType.ByValTStr,SizeConst=128)]

private string durLength = "" ;

[MarshalAs(UnmanagedType.LPTStr,SizeConst=128)]

private string TemStr ="";

int ilong;

//定义播放状态枚举变量

public enum State

{

  mPlaying = 1,

  mPuase = 2,

  mStop = 3

};

//结构变量

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() ;

//取得播放文件属性

public string FileName

{

  get

  {

return mc.iName;

  }

  set

  {

//ASCIIEncoding asc = new ASCIIEncoding();

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";

  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

{

  MessageBox.Show("出错错误!");

}

  }

}

//播放

public void play()

{

  TemStr = "";

  TemStr = TemStr.PadLeft(127,Convert.ToChar(" "));

  APIClass.mciSendString("play media", TemStr, TemStr.Length , 0);

  mc.state = State.mPlaying ;

}

//停止

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 = "";

  TemS
tr = 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;

}

//总时间

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);

  }

}

//当前时间

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

);

  }

}

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