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(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 = "";
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;
}
//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", CharSet = CharSet.Auto)]
public static extern int mciSendString(
string lpstrCommand,
string lpstrReturnString,
int uReturnLength,
int hwndCallback
);
}
}
二、用于测试媒体播放类的简单代码：
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Runtime.InteropServices;
using System.Text;
using System.IO;
using clsMCIPlay;
namespace MCIPlay
...{
/**////
/// Form1 的摘要说明。
///
public class Form1 : Form
...{
private IContainer components;
private Timer timer1;
private Button Play;
private Button Stop;
private Button Puase;
private Label PlayFileName;
private Label Duration;
private Label CurrentPosition;
private OpenFileDialog openFileDialog1;
private Button BrowserFile;
clsMCI mp = new clsMCI();
public Form1()
...{
//
// Windows 窗体设计器支持所必需的
//
InitializeComponent();
//
// TODO: 在 InitializeComponent
// 调用后添加任何构造函数代码
//
}
/**////
/// 清理所有正在使用的资源。
///
protected override void Dispose(bool disposing)
...{
if (disposing)
...{
if (components != null)
...{
components.Dispose();
}
}
base.Dispose(disposing);
}
Windows 窗体设计器生成的代码#region Windows 窗体设计器生成的代码
/**////
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
///
private void InitializeComponent()
...{
this.components = new Container();
this.Play = new Button();
this.PlayFileName = new Label();
this.Duration = new Label();
this.Stop = new Button();
this.Puase = new Button();
this.CurrentPosition = new Label();
this.timer1 = new Timer(this.components);
this.openFileDialog1 = new OpenFileDialog();
this.BrowserFile = new Button();
this.SuspendLayout();
//
// Play
//
this.Play.Location = new Point(102, 243);
this.Play.Name = "Play";
this.Play.Size = new Size(78, 24);
this.Play.TabIndex = 0;
this.Play.Text = "Play";
this.Play.Click +=
new EventHandler(this.Play_Click);
//
// PlayFileName
//
this.PlayFileName.AutoSize = true;
this.PlayFileName.Location = new Point(12, 15);
this.PlayFileName.Name = "PlayFileName";
this.PlayFileName.Size = new Size(0, 17);
this.PlayFileName.TabIndex = 1;
//
// Duration
//
this.Duration.AutoSize = true;
this.Duration.Location = new Point(15, 51);
this.Duration.Name = "Duration";
this.Duration.Size = new Size(0, 17);
this.Duration.TabIndex = 2;
//
// Stop
//
this.Stop.Location = new Point(282, 243);
this.Stop.Name = "Stop";
this.Stop.Size = new Size(81, 24);
this.Stop.TabIndex = 3;
this.Stop.Text = "Stop";
this.Stop.Click +=
new EventHandler(this.Stop_Click);
//
// Puase
//
this.Puase.Location = new Point(198, 243);
this.Puase.Name = "Puase";
this.Puase.Size = new Size(72, 24);
this.Puase.TabIndex = 4;
this.Puase.Text = "Puase";
this.Puase.Click +=
new EventHandler(this.Puase_Click);
//
// CurrentPosition
//
this.CurrentPosition.AutoSize = true;
this.CurrentPosition.Location = new Point(15, 87);
this.CurrentPosition.Name = "CurrentPosition";
this.CurrentPosition.Size = new Size(0, 17);
this.CurrentPosition.TabIndex = 5;
//
// timer1
//
this.timer1.Enabled = true;
this.timer1.Interval = 1000;
this.timer1.Tick +=
new EventHandler(this.timer1_Tick);
//
// BrowserFile
//
this.BrowserFile.Location = new Point(312, 165);
this.BrowserFile.Name = "BrowserFile";
this.BrowserFile.Size = new Size(87, 24);
this.BrowserFile.TabIndex = 6;
this.BrowserFile.Text = "SelectFile";
this.BrowserFile.Click +=
new EventHandler(this.BrowserFile_Click);
//
// Form1
//
this.AutoScaleBaseSize = new Size(6, 14);
this.ClientSize = new Size(433, 287);
this.Controls.Add(this.BrowserFile);
this.Controls.Add(this.CurrentPosition);
this.Controls.Add(this.Puase);
this.Controls.Add(this.Stop);
this.Controls.Add(this.Duration);
this.Controls.Add(this.PlayFileName);
this.Controls.Add(this.Play);
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);
}
#endregion
/**////
/// 应用程序的主入口点。
///
[STAThread]
static void Main()
...{
Application.Run(new Form1());
}
//选择MP3文件播放
private void Play_Click(
object sender, System.EventArgs e)
...{
try
...{
mp.play();
}
catch
...{
MessageBox.Show("出错错误!");
}
}
//暂停播放
private void Puase_Click(
object sender, System.EventArgs e)
...{
try
...{
mp.Puase();
}
catch
...{
MessageBox.Show("出错错误!");
}
}
//停止播放
private void Stop_Click(
object sender, System.EventArgs e)
...{
try
...{
mp.StopT();
}
catch
...{
MessageBox.Show("出错错误!");
}
}
//每秒显示一次播放进度
private void timer1_Tick(
object sender, System.EventArgs e)
...{
CurrentPosition.Text =
mp.CurrentPosition.ToString();
}
//浏览文件
private void BrowserFile_Click(
object sender, System.EventArgs e)
...{
try
...{
openFileDialog1.Filter = "*.mp3|*.mp3";
openFileDialog1.FileName = "";
if (openFileDialog1.ShowDialog() == DialogResult.OK)
...{
mp.FileName = openFileDialog1.FileName;
PlayFileName.Text = openFileDialog1.FileName;
Duration.Text = mp.Duration.ToString();
}
}
catch
...{
MessageBox.Show("出错错误!");
}
}
}
}
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