C#沒有提供播放MP3等音頻文件的類,要編寫播放MP3等音頻文件程序,必須使用第三方控件或類。本文使用API函數mciSendString,編寫一個播放MP3等音頻文件的類。
具體源碼如下:
一、使用API函數mciSendString構成的媒體播放類。
using System; using System.Runtime.InteropServices; using System.Text; using System.IO ; namespace clsMCIPlay { /// <summary> /// clsMci 的摘要說明。 /// </summary> public class clsMCI { public clsMCI() { // // TODO: 在此處添加構造函數邏輯 // } //定義API函數使用的字符串變量 [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; //定義播放狀態枚舉變量 public enum State { mPlaying = 1, mPuase = 2, mStop = 3 }; //結構變量 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() ; //取得播放文件屬性 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("出錯錯誤!"); } } } //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 = ""; 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; } //總時間 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); } } //當前時間 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 ); } }