[C#] 音乐播放 3 种方式 Demo 与 MCI 音乐播放器封装类.

淦!#

首先代码是不完整的, 我还是没能成功设置音量, 除此之外, 别的倒是挺顺利的, 当前实现的功能如下:

播放暂停还原停止获取进度获取长度设置进度获取播放状态

内容:#

本项目的仓库在: SlimeNull/AudioTest, 在这里下载哦, 别忘了还原 nuget 包, 因为用了 NAudio 库.

> 音乐播放 Demo:#

先放图吧:

首先左上角是打开文件的, 然后 PlayType 是播放方式, 我现在让它支持 3 种, 一种是SoundPlayer, 然后是 MCI, 然后是 NAudio 库. 实现了播放, 暂停, 停止, 移除, 进度调整到开头, 进度调整(就那个track bar), 同步播放(如果点了这个, UI线程会阻塞的哦), 获取音乐长度, 获取播放状态, 获取播放位置, 重复播放. 不同的功能对不同的播放种类支持性不同, 所以, 如果你按下了按钮, 没反应, 也没报错, 那就是它不支持这个功能(也就是代码里没有写)’

下载代码, 请看前面的链接.↑跳转↑

> MCI 播放器封装:#

上边的窗体程序就体现了封装类所实现的所有功能喔, 所以试试吧, 你也可以直接粘贴下面的代码, 但是cs文件的名称, 如果可以的话, 我希望你命名为 “Null.MciPlayer” _{(没错就是我的名字}

using System;
using System.IO;
using System.Runtime.InteropServices;

namespace Null.MciPlayer
{
    public class MciPlayer : IDisposable
    {
        [DllImport("kernel32.dll", EntryPoint = "GetShortPathNameW", CharSet = CharSet.Unicode)]
        extern static short GetShortPath(string longPath, string buffer, int bufferSize);
        [DllImport("winmm.dll", EntryPoint = "mciSendString", CharSet = CharSet.Unicode)]
        extern static int MciSendString(string command, string buffer, int bufferSize, IntPtr callback);

        bool TryGetShortPath(string longPath, out string shortPath)
        {
            shortPath = null;
            short reqLen = GetShortPath(longPath, null, 0);   // 指定 null与0, 则返回需要的长度
            if (reqLen == 0)
                return false;

            shortPath = new string('\0', reqLen);   // 声明缓冲

            short rstLen = GetShortPath(longPath, shortPath, reqLen);   // 转换
            if (rstLen == 0 || rstLen == reqLen)
                return false;

            shortPath = shortPath.TrimEnd('\0');
            return true;
        }

        private string longpath;
        private string shortName;
        private string aliasName;
        public MciPlayer() { }
        public MciPlayer(string path)
        {
            if (!File.Exists(path))
                throw new FileNotFoundException("File not exist.", path);

            longpath = path;
        }
        void MciSendStringWithCheck(string command, string buffer, int bufferSize, IntPtr callback)
        {
            int err = MciSendString(command, buffer, bufferSize, callback);
            if (err != 0)
                throw new MciException(err);
        }
        string StatusInfo(string info)
        {
            string buffer = new string('\0', 32);
            MciSendStringWithCheck($"status {aliasName} {info}", buffer, 32, IntPtr.Zero);

            return buffer.TrimEnd('\0');
        }



        public string DevicePath { get => longpath; }
        public string DeviceShortPath { get => shortName; }
        public string AliasName { get => aliasName; }
        public bool SetDevicePath(string longpath)
        {
            if (aliasName != null)
                return false;

            this.longpath = longpath;
            return true;
        }
        public void Open()
        {
            if (!TryGetShortPath(longpath, out shortName))
                throw new Exception("Get short path faield when initializing.");

            aliasName = $"nmci{DateTime.Now.Ticks}";
            MciSendStringWithCheck($"open {shortName} alias {aliasName}", null, 0, IntPtr.Zero);
        }
        public void Close()
        {
            MciSendStringWithCheck($"close {aliasName}", null, 0, IntPtr.Zero);

            aliasName = null;
        }
        public void Play()
        {
            MciSendStringWithCheck($"play {aliasName}", null, 0, IntPtr.Zero);
        }
        public void Resume()
        {
            MciSendStringWithCheck($"resume {aliasName}", null, 0, IntPtr.Zero);
        }
        public void Pause()
        {
            MciSendStringWithCheck($"pause {aliasName}", null, 0, IntPtr.Zero);
        }
        public void Stop()
        {
            MciSendStringWithCheck($"stop {aliasName}", null, 0, IntPtr.Zero);
        }
        public int GetPosition()
        {
            return int.Parse(StatusInfo("position"));
        }
        public int GetLength()
        {
            return int.Parse(StatusInfo("length"));
        }
        public PlaybackState GetState()
        {
            switch (StatusInfo("mode").ToLower())
            {
                case "playing":
                    return PlaybackState.Playing;
                case "paused":
                    return PlaybackState.Paused;
                case "stopped":
                    return PlaybackState.Stopped;
                default:
                    return PlaybackState.Invalid;
            }
        }
        public void PlayWait()
        {
            MciSendStringWithCheck($"play {aliasName} wait", null, 0, IntPtr.Zero);
        }
        public void PlayRepeat()
        {
            MciSendStringWithCheck($"play {aliasName} repeat", null, 0, IntPtr.Zero);
        }
        public void Seek(int position)
        {
            MciSendStringWithCheck($"seek {aliasName} to {position}", null, 0, IntPtr.Zero);
        }
        public void SeekToStart()
        {
            MciSendStringWithCheck($"seek {aliasName} to start", null, 0, IntPtr.Zero);
        }
        public void SetSeekMode(bool fExact)
        {
            MciSendStringWithCheck($"set {aliasName} seek exactly {(fExact ? "on" : "off")}", null, 0, IntPtr.Zero);
        }
        public void Dispose()
        {
            if (aliasName != null)
                Close();
        }

    }
    public enum PlaybackState
    {
        Stopped,
        Playing,
        Paused,

        Invalid = -1,
    }
    public class MciException : Exception
    {
        private MciError err;

        public int ErrorId { get => (int)err; }
        public string ErrorName { get => err.ToString(); }
        public override string Message { get => ErrorName; }
        public MciException() { }
        public MciException(int errorId)
        {
            if (Enum.IsDefined(typeof(MciError), errorId))
                err = (MciError)errorId;
            else
                throw new ArgumentOutOfRangeException("不是正确的错误ID");
        }
        public MciException(string errorName)
        {
            if (!Enum.TryParse<MciError>(errorName, out err))
                throw new ArgumentOutOfRangeException("不是正确的错误ID");
        }
        enum MciError
        {
            MCIERR_NO_ERROR = 0,

            MCIERR_INVALID_DEVICE_ID = 257,
            MCIERR_UNRECOGNIZED_KEYWORD = 259,
            MCIERR_UNRECOGNIZED_COMMAND = 261,
            MCIERR_HARDWARE = 262,
            MCIERR_INVALID_DEVICE_NAME = 263,
            MCIERR_OUT_OF_MEMORY = 264,
            MCIERR_DEVICE_OPEN = 265,
            MCIERR_CANNOT_LOAD_DRIVER = 266,
            MCIERR_MISSING_COMMAND_STRING = 267,
            MCIERR_PARAM_OVERFLOW = 268,
            MCIERR_MISSING_STRING_ARGUMENT = 269,
            MCIERR_BAD_INTEGER = 270,
            MCIERR_PARSER_INTERNAL = 271,
            MCIERR_DRIVER_INTERNAL = 272,
            MCIERR_MISSING_PARAMETER = 273,
            MCIERR_UNSUPPORTED_FUNCTION = 274,
            MCIERR_FILE_NOT_FOUND = 275,
            MCIERR_DEVICE_NOT_READY = 276,
            MCIERR_INTERNAL = 277,
            MCIERR_DRIVER = 278,
            MCIERR_CANNOT_USE_ALL = 279,
            MCIERR_MULTIPLE = 280,
            MCIERR_EXTENSION_NOT_FOUND = 281,
            MCIERR_OUTOFRANGE = 282,
            MCIERR_FLAGS_NOT_COMPATIBLE = 284,
            MCIERR_FILE_NOT_SAVED = 286,
            MCIERR_DEVICE_TYPE_REQUIRED = 287,
            MCIERR_DEVICE_LOCKED = 288,
            MCIERR_DUPLICATE_ALIAS = 289,
            MCIERR_BAD_CONSTANT = 290,
            MCIERR_MUST_USE_SHAREABLE = 291,
            MCIERR_MISSING_DEVICE_NAME = 292,
            MCIERR_BAD_TIME_FORMAT = 293,
            MCIERR_NO_CLOSING_QUOTE = 294,
            MCIERR_DUPLICATE_FLAGS = 295,
            MCIERR_INVALID_FILE = 296,
            MCIERR_NULL_PARAMETER_BLOCK = 297,
            MCIERR_UNNAMED_RESOURCE = 298,
            MCIERR_NEW_REQUIRES_ALIAS = 299,
            MCIERR_NOTIFY_ON_AUTO_OPEN = 300,
            MCIERR_NO_ELEMENT_ALLOWED = 301,
            MCIERR_NONAPPLICABLE_FUNCTION = 302,
            MCIERR_ILLEGAL_FOR_AUTO_OPEN = 303,
            MCIERR_FILENAME_REQUIRED = 304,
            MCIERR_EXTRA_CHARACTERS = 305,
            MCIERR_DEVICE_NOT_INSTALLED = 306,
            MCIERR_GET_CD = 307,
            MCIERR_SET_CD = 308,
            MCIERR_SET_DRIVE = 309,
            MCIERR_DEVICE_LENGTH = 310,
            MCIERR_DEVICE_ORD_LENGTH = 311,
            MCIERR_NO_INTEGER = 312,

            MCIERR_WAVE_OUTPUTSINUSE = 320,
            MCIERR_WAVE_SETOUTPUTINUSE = 321,
            MCIERR_WAVE_INPUTSINUSE = 322,
            MCIERR_WAVE_SETINPUTINUSE = 323,
            MCIERR_WAVE_OUTPUTUNSPECIFIED = 324,
            MCIERR_WAVE_INPUTUNSPECIFIED = 325,
            MCIERR_WAVE_OUTPUTSUNSUITABLE = 326,
            MCIERR_WAVE_SETOUTPUTUNSUITABLE = 327,
            MCIERR_WAVE_INPUTSUNSUITABLE = 328,
            MCIERR_WAVE_SETINPUTUNSUITABLE = 329,

            MCIERR_SEQ_DIV_INCOMPATIBLE = 336,
            MCIERR_SEQ_PORT_INUSE = 337,
            MCIERR_SEQ_PORT_NONEXISTENT = 338,
            MCIERR_SEQ_PORT_MAPNODEVICE = 339,
            MCIERR_SEQ_PORT_MISCERROR = 340,
            MCIERR_SEQ_TIMER = 341,
            MCIERR_SEQ_PORTUNSPECIFIED = 342,
            MCIERR_SEQ_NOMIDIPRESENT = 343,

            MCIERR_NO_WINDOW = 346,
            MCIERR_CREATEWINDOW = 347,
            MCIERR_FILE_READ = 348,
            MCIERR_FILE_WRITE = 349,
            MCIERR_NO_IDENTITY = 350,
        }
    }
}

如果有什么建议或者这个类有可改进的地方, 欢迎留言哦~ n(*≧▽≦*)n