语音识别这个功能属于高级功能，必须微信实名认证后才能实现，认证费用300元/年，如果你作为开发者可以申请测试帐号，也是可以的。实现这个功能就要用到之前在第二章提到的Accesstoken了，首先建立一个微信消息类，这个类比之前多了一个属性。
class wxmessage
{
public string FromUserName { get; set; }
public string ToUserName { get; set; }
public string MsgType { get; set; }
public string EventName { get; set; }
public string Content { get; set; }
public string Recognition { get; set; }
public string EventKey { get; set; }
}
protected void Page_Load(object sender, EventArgs e)
{
wxmessage wx = GetWxMessage();
string res = "";
if (!string.IsNullOrEmpty(wx.EventName) && wx.EventName.Trim() == "subscribe")
{//刚关注时的时间，用于欢迎词
string content = "";
content = "/:rose欢迎北京永杰友信科技有限公司/:rose\n直接回复“你好”";
res = sendTextMessage(wx, content);
}
else
{
if (wx.MsgType == "text" && wx.Content == "你好")
{
res = sendTextMessage(wx, "你好,欢迎使用北京永杰友信科技有限公司公共微信平台!");
}
else if (wx.MsgType == "voice")//识别消息类型为语音
{
res = sendTextMessage(wx, wx.Recognition);//wx.Recognition就是语音识别的结果了，我们直接引用，以文本形式反馈就OK了
}
else
{
res = sendTextMessage(wx, "你好,未能识别消息!");
}
}
Response.Write(res);
}
private wxmessage GetWxMessage()
{
wxmessage wx = new wxmessage();
StreamReader str = new StreamReader(Request.InputStream, System.Text.Encoding.UTF8);
XmlDocument xml = new XmlDocument();
xml.Load(str);
wx.ToUserName = xml.SelectSingleNode("xml").SelectSingleNode("ToUserName").InnerText;
wx.FromUserName = xml.SelectSingleNode("xml").SelectSingleNode("FromUserName").InnerText;
wx.MsgType = xml.SelectSingleNode("xml").SelectSingleNode("MsgType").InnerText;
if (wx.MsgType.Trim() == "text")
{
wx.Content = xml.SelectSingleNode("xml").SelectSingleNode("Content").InnerText;
}
if (wx.MsgType.Trim() == "event")
{
wx.EventName = xml.SelectSingleNode("xml").SelectSingleNode("Event").InnerText;
}
if (wx.MsgType.Trim() == "voice")//如果是语音消息的话就把识别结果赋值给实体类的相应属性Recognition
{
wx.Recognition = xml.SelectSingleNode("xml").SelectSingleNode("Recognition").InnerText;
}
return wx;
}