Question

我正在尝试在午餐时间将一个（非常）粗糙的MP3播放器捆绑在一起，到目前为止，我已经有了它来播放这些文件，而我正在努力建立一个文件名列表来启用随机歌曲，但我想我只是遇到了障碍。

有没有办法知道当前播放的MP3何时播出？一个事件还是一些这样的？目前我不认为我能够有播放列表等，除非这是因为它在每次播放后都停止了。

我已经把下面的整个来源都搞定了，随意挑选它并给我任何反馈，欢呼。

using System;
using System.IO;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace X
{
public partial class Form1 : Form
{
    List<string> Names = new List<string>();
    StreamReader reader = File.OpenText(@"C:\X.txt");
    string line;
    OpenFileDialog ofd = new OpenFileDialog();
    StringBuilder buffer = new StringBuilder(128);
    string CommandString;
    [DllImport("winmm.dll")]
    private static extern long mciSendString(string lpstrCommand, StringBuilder lpstrReturnString, int uReturnLength, int hwndCallback);
    public Form1()
    {
        InitializeComponent();
        while ((line = reader.ReadLine()) != null)
        {
            if (line.Trim() != "")
            {
                Names.Add(line.Trim());
            }
        }
    }

    private void btnplay_Click(object sender, EventArgs e)
    {
        if (ofd.FileName == "")
        {
            if (ofd.ShowDialog() == DialogResult.OK)
            {
                ofd.Filter = "MP3 Files|*.mp3";
                CommandString = "open " + "\"" + ofd.FileName + "\"" + " type MPEGVideo alias Mp3File";
                mciSendString(CommandString, null, 0, 0);
                CommandString = "play Mp3File";
                mciSendString(CommandString, null, 0, 0);
            }
        }

        else
        {
            CommandString = "play Mp3File";
            mciSendString(CommandString, null, 0, 0);
        }
    }

    private void btnpause_Click(object sender, EventArgs e)
    {
        CommandString = "pause mp3file";
        mciSendString(CommandString, null, 0, 0);
    }

    private void btnbrowse_Click(object sender, EventArgs e)
    {
        ofd.Filter = "Mp3 files |*.mp3";
        if (ofd.ShowDialog() == DialogResult.OK)
        {
            txtpath.Text = ofd.FileName;
            CommandString = "close Mp3File";
            mciSendString(CommandString, null, 0, 0);
            CommandString = "open " + "\"" + ofd.FileName + "\"" + " type MPEGVideo alias Mp3File";
            mciSendString(CommandString, null, 0, 0);
        }
    }
}
}

Answer 1

当您调用mcisendstring打开文件时，您可以从mcisendstring命令获取通知，只需发送表单的句柄并覆盖表单的wndproc方法，然后您可以从MCI示例代码获取通知，如下所示。

 private void btnplay_Click(object sender, EventArgs e)
{
    if (ofd.FileName == "")
    {
        if (ofd.ShowDialog() == DialogResult.OK)
        {
            ofd.Filter = "MP3 Files|*.mp3";
            CommandString = "open " + "\"" + ofd.FileName + "\"" + " type MPEGVideo alias Mp3File";
            mciSendString(CommandString, null, 0, this.Handle.ToInt64());
            CommandString = "play Mp3File";
            mciSendString(CommandString, null, 0, this.Handle.ToInt64());
        }
    }

    else
    {
        CommandString = "play Mp3File";
        mciSendString(CommandString, null, 0, this.Handle.ToInt64());
    }
}

// Declare the nofify constant
public const int MM_MCINOTIFY = 953;

// Override the WndProc function in the form
protected override void WndProc(ref Message m) 
{

    if (m.Msg == MM_MCINOTIFY)
    {
        // The file is done playing, do whatever
    }
    base.WndProc(ref m);
}

使用winmm.dll的C＃MP3播放器

1 个答案: