Detailed explanation of the upload and download function of WeChat voice

<p class="inp_btn voice_btn active" id="record">
       按住 说话
     </p>

var recorder;
var btnRecord = $('#record');
var startTime = 0;
var recordTimer = 300;
// 发语音
$.ajax({
  url: 'url请求需要微信的一些东西 下面success就是返回的东西',
  type: 'get',
  data: { url: url },
  success: function (data) {
    var json = $.parseJSON(data);
    //alert(json);
    //假设已引入微信jssdk。【支持使用 AMD/CMD 标准模块加载方法加载】
    wx.config({
      debug: false, // 开启调试模式,调用的所有api的返回值会在客户端alert出来，若要查看传入的参数，可以在pc端打开，参数信息会通过log打出，仅在pc端时才会打印。
      appId: json.appid, // 必填，公众号的唯一标识
      timestamp: json.timestamp, // 必填，生成签名的时间戳
      nonceStr: json.nonceStr, // 必填，生成签名的随机串
      signature: json.signature, // 必填，签名，见附录1
      jsApiList: [
      "startRecord",
      "stopRecord",
      "onVoiceRecordEnd",
      "playVoice",
      "pauseVoice",
      "stopVoice",
      "onVoicePlayEnd",
      "uploadVoice",
      "downloadVoice",
      ] // 必填，需要使用的JS接口列表，所有JS接口列表见附录2
    });
    wx.ready(function () {
      btnRecord.on('touchstart', function (event) {
        event.preventDefault();
        startTime = new Date().getTime();
        // 延时后录音，避免误操作
        recordTimer = setTimeout(function () {
          wx.startRecord({
            success: function () {
              localStorage.rainAllowRecord = 'true';
              //style="display:block"
              $(".voice_icon").css("display", "block");
            },
            cancel: function () {
              layer.open({
                content: '用户拒绝了录音授权',
                btn: '确定',
                shadeClose: false,
              });
            }
          });
        }, 300);
      }).on('touchend', function (event) {
        event.preventDefault();
        // 间隔太短
        if (new Date().getTime() - startTime < 300) {
          startTime = 0;
          // 不录音
          clearTimeout(recordTimer);
        } else { // 松手结束录音
          wx.stopRecord({
            success: function (res) {
              $(".voice_icon").css("display", "none");
              voice.localId = res.localId;
              // 上传到服务器
              uploadVoice();
            },
            fail: function (res) {
              //alert(JSON.stringify(res));
              layer.open({
                content: JSON.stringify(res),
                btn: &#39;确定&#39;,
                shadeClose: false,
              });
            }
          });
        }
      });
    });
  },
  error: function () { }
})

function uploadVoice() {
    //调用微信的上传录音接口把本地录音先上传到微信的服务器
    //不过，微信只保留3天，而我们需要长期保存，我们需要把资源从微信服务器下载到自己的服务器
    wx.uploadVoice({
      localId: voice.localId, // 需要上传的音频的本地ID，由stopRecord接口获得
      isShowProgressTips: 1, // 默认为1，显示进度提示
      success: function (res) {
        // alert(JSON.stringify(res));
        //把录音在微信服务器上的id（res.serverId）发送到自己的服务器供下载。
        voice.serverId = res.serverId;
        $.ajax({
          url: '/QyhSpeech/DownLoadVoice',
          type: 'post',
          data: { serverId: res.serverId, Id: Id },
          dataType: "json",
          success: function (data) {
            if (data.Result == true && data.ResultCode == 1) {
              layer.open({
                content: "录音上传完成！",//data.Message
                btn: '确定',
                shadeClose: false,
                yes: function (index) {
                  window.location.href = window.location.href;
                }
              });
            }
            else {
              layer.open({
                content: data.Message,
                btn: '确定',
                shadeClose: false,
              });
            }
          },
          error: function (xhr, errorType, error) {
            layer.open({
              content: error,
              btn: '确定',
              shadeClose: false,
            });
          }
        });
      }
    });
  }

//下载语音并且转换的方法
    private string GetVoicePath(string voiceId, string access_token)
    {
      string voice = "";
      try
      {
        Log.Debug("access_token:", access_token);
        //调用downloadmedia方法获得downfile对象
        DownloadFile downFile = WeiXin.DownloadMedia(voiceId, access_token);
        if (downFile.Stream != null)
        {
          string fileName = Guid.NewGuid().ToString();
          //生成amr文件
          string amrPath = Server.MapPath("~/upload/audior/");
          if (!Directory.Exists(amrPath))
          {
            Directory.CreateDirectory(amrPath);
          }
          string amrFilename = amrPath + fileName + ".amr";
          //var ss = GetAMRFileDuration(amrFilename);
          //Log.Debug("ss", ss.ToString());
          using (FileStream fs = new FileStream(amrFilename, FileMode.Create))
          {
            byte[] datas = new byte[downFile.Stream.Length];
            downFile.Stream.Read(datas, 0, datas.Length);
            fs.Write(datas, 0, datas.Length);
          }
          //转换为mp3文件
          string mp3Path = Server.MapPath("~/upload/audio/");
          if (!Directory.Exists(mp3Path))
          {
            Directory.CreateDirectory(mp3Path);
          }
          string mp3Filename = mp3Path + fileName + ".mp3";
          AudioHelper.ConvertToMp3(Server.MapPath("~/ffmpeg/"), amrFilename, mp3Filename);
          voice = fileName;
          Log.Debug("voice:", voice);
        }
      }
      catch { }
      return voice;
    }

//下载微信语音文件
    public JsonResult DownLoadVoice()
    {
      var file = "";
      try
      {
        var serverId = Request["serverId"];//文件的serverId
        file = GetVoicePath(serverId, CacheHelper.GetAccessToken());
        return Json(new ResultJson { Message = file, Result = true, ResultCode = 1 });
      }
      catch (Exception ex)
      {
        return Json(new ResultJson { Message = ex.Message, Result = false, ResultCode = 0 });
      }
    }

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
namespace EYO.Common
{
  /// <summary>
  /// 声音帮助类
  /// </summary>
  public sealed class AudioHelper
  {
    private const string FfmpegUsername = "ffmpeg";
    private const string FfmpegPassword = "it4pl803";
    /// <summary>
    /// 音频转换
    /// </summary>
    /// <param name="ffmpegPath">ffmpeg文件目录</param>
    /// <param name="soruceFilename">源文件</param>
    /// <param name="targetFileName">目标文件</param>
    /// <returns></returns>
    public static string ConvertToMp3(string ffmpegPath, string soruceFilename, string targetFileName)
    {
      //string cmd = ffmpegPath + @"\ffmpeg.exe -i " + soruceFilename + " " + targetFileName;
      string cmd = ffmpegPath + @"\ffmpeg.exe -i " + soruceFilename + " -ar 44100 -ab 128k " + targetFileName;
      return ConvertWithCmd(cmd);
    }
    private static string ConvertWithCmd(string cmd)
    {
      try
      {
        System.Diagnostics.Process process = new System.Diagnostics.Process();
        process.StartInfo.FileName = "cmd.exe";
        process.StartInfo.UseShellExecute = false;
        process.StartInfo.CreateNoWindow = true;
        process.StartInfo.RedirectStandardInput = true;
        process.StartInfo.RedirectStandardOutput = true;
        process.StartInfo.RedirectStandardError = true;
        process.Start();
        process.StandardInput.WriteLine(cmd);
        process.StandardInput.AutoFlush = true;
        Thread.Sleep(1000);
        process.StandardInput.WriteLine("exit");
        process.WaitForExit();
        string outStr = process.StandardOutput.ReadToEnd();
        process.Close();
        return outStr;
      }
      catch (Exception ex)
      {
        return "error" + ex.Message;
      }
    }
  }
}