说起微信公众帐号，大家都不会陌生，使用这个平台能给网站或系统增加一个新亮点，直接进入正题吧，在使用之前一定要仔细阅读官方API文档。
API文档地址：http://mp.weixin.qq.com/wiki/index.php

使用.net实现的方法：
//微信接口地址 页面代码:

复制代码 代码如下:
weixin _wx = new weixin(); 
string postStr = ""; 
if (Request.HttpMethod.ToLower() == "post") 
{ 
Stream s = System.Web.HttpContext.Current.Request.InputStream; 
byte[] b = new byte[s.Length]; 
s.Read(b, 0, (int)s.Length); 
postStr = Encoding.UTF8.GetString(b); 
if (!string.IsNullOrEmpty(postStr)) //请求处理 
{ 
_wx.Handle(postStr);  
} 
} 
else
{ 
_wx.Auth(); 
}

具体处理类

复制代码 代码如下:
/// <summary> 
/// 微信公众平台操作类 
/// </summary> 
public class weixin 
{ 
private string Token = "my_weixin_token"; //换成自己的token 
public void Auth() 
{ 
string echoStr = System.Web.HttpContext.Current.Request.QueryString["echoStr"]; 
if (CheckSignature()) //校验签名是否正确 
{ 
if (!string.IsNullOrEmpty(echoStr)) 
{ 
System.Web.HttpContext.Current.Response.Write(echoStr); //返回原值表示校验成功 
System.Web.HttpContext.Current.Response.End(); 
} 
} 
} 

 
public void Handle(string postStr) 
{ 
//封装请求类 
XmlDocument doc = new XmlDocument(); 
doc.LoadXml(postStr); 
XmlElement rootElement = doc.DocumentElement; 
//MsgType 
XmlNode MsgType = rootElement.SelectSingleNode("MsgType"); 
//接收的值--->接收消息类(也称为消息推送) 
RequestXML requestXML = new RequestXML(); 
requestXML.ToUserName = rootElement.SelectSingleNode("ToUserName").InnerText; 
requestXML.FromUserName = rootElement.SelectSingleNode("FromUserName").InnerText; 
requestXML.CreateTime = rootElement.SelectSingleNode("CreateTime").InnerText; 
requestXML.MsgType = MsgType.InnerText; 

//根据不同的类型进行不同的处理 
switch (requestXML.MsgType) 
{ 
case "text": //文本消息 
requestXML.Content = rootElement.SelectSingleNode("Content").InnerText; 
break; 
case "image": //图片 
requestXML.PicUrl = rootElement.SelectSingleNode("PicUrl").InnerText; 
break; 
case "location": //位置 
requestXML.Location_X = rootElement.SelectSingleNode("Location_X").InnerText; 
requestXML.Location_Y = rootElement.SelectSingleNode("Location_Y").InnerText; 
requestXML.Scale = rootElement.SelectSingleNode("Scale").InnerText; 
requestXML.Label = rootElement.SelectSingleNode("Label").InnerText; 
break; 
case "link": //链接 
break; 
case "event": //事件推送 支持V4.5+ 
break; 
} 

//消息回复 
ResponseMsg(requestXML); 
} 

 
/// <summary> 
/// 验证微信签名 
/// * 将token、timestamp、nonce三个参数进行字典序排序 
/// * 将三个参数字符串拼接成一个字符串进行sha1加密 
/// * 开发者获得加密后的字符串可与signature对比，标识该请求来源于微信。 
/// </summary> 
/// <returns></returns> 
private bool CheckSignature() 
{ 
string signature = System.Web.HttpContext.Current.Request.QueryString["signature"]; 
string timestamp = System.Web.HttpContext.Current.Request.QueryString["timestamp"]; 
string nonce = System.Web.HttpContext.Current.Request.QueryString["nonce"]; 
//加密/校验流程： 
//1. 将token、timestamp、nonce三个参数进行字典序排序 
string[] ArrTmp = { Token, timestamp, nonce };  
Array.Sort(ArrTmp);//字典排序 
//2.将三个参数字符串拼接成一个字符串进行sha1加密 
string tmpStr = string.Join("", ArrTmp); 
tmpStr = FormsAuthentication.HashPasswordForStoringInConfigFile(tmpStr, "SHA1"); 
tmpStr = tmpStr.ToLower(); 
//3.开发者获得加密后的字符串可与signature对比，标识该请求来源于微信。 
if (tmpStr == signature) 
{ 
return true; 
} 
else
{ 
return false; 
} 
} 

/// <summary> 
/// 消息回复(微信信息返回) 
/// </summary> 
/// <param name="requestXML">The request XML.</param> 
private void ResponseMsg(RequestXML requestXML) 
{ 
try
{ 
string resxml = ""; 
//主要是调用数据库进行关键词匹配自动回复内容，可以根据自己的业务情况编写。 
//1.通常有，没有匹配任何指令时，返回帮助信息 
AutoResponse mi = new AutoResponse(requestXML.Content, requestXML.FromUserName); 

switch (requestXML.MsgType) 
{ 
case "text": 
//在这里执行一系列操作，从而实现自动回复内容.  
string _reMsg = mi.GetReMsg(); 
if (mi.msgType == 1) 
{ 
resxml = "<xml><ToUserName><![CDATA[" + requestXML.FromUserName + "]]></ToUserName><FromUserName><![CDATA[" + requestXML.ToUserName + "]]></FromUserName><CreateTime>" + ConvertDateTimeInt(DateTime.Now) + "</CreateTime><MsgType><![CDATA[news]]></MsgType><Content><![CDATA[]]></Content><ArticleCount>2</ArticleCount><Articles>"; 
resxml += mi.GetRePic(requestXML.FromUserName); 
resxml += "</Articles><FuncFlag>1</FuncFlag></xml>"; 
} 
else
{ 
resxml = "<xml><ToUserName><![CDATA[" + requestXML.FromUserName + "]]></ToUserName><FromUserName><![CDATA[" + requestXML.ToUserName + "]]></FromUserName><CreateTime>" + ConvertDateTimeInt(DateTime.Now) + "</CreateTime><MsgType><![CDATA[text]]></MsgType><Content><![CDATA[" + _reMsg + "]]></Content><FuncFlag>1</FuncFlag></xml>"; 
} 
break; 
case "location": 
string city = GetMapInfo(requestXML.Location_X, requestXML.Location_Y); 
if (city == "0") 
{ 
resxml = "<xml><ToUserName><![CDATA[" + requestXML.FromUserName + "]]></ToUserName><FromUserName><![CDATA[" + requestXML.ToUserName + "]]></FromUserName><CreateTime>" + ConvertDateTimeInt(DateTime.Now) + "</CreateTime><MsgType><![CDATA[text]]></MsgType><Content><![CDATA[好啦，我们知道您的位置啦。您可以:" + mi.GetDefault() + "]]></Content><FuncFlag>1</FuncFlag></xml>"; 
} 
else
{ 
resxml = "<xml><ToUserName><![CDATA[" + requestXML.FromUserName + "]]></ToUserName><FromUserName><![CDATA[" + requestXML.ToUserName + "]]></FromUserName><CreateTime>" + ConvertDateTimeInt(DateTime.Now) + "</CreateTime><MsgType><![CDATA[text]]></MsgType><Content><![CDATA[好啦，我们知道您的位置啦。您可以:" + mi.GetDefault() + "]]></Content><FuncFlag>1</FuncFlag></xml>"; 
} 
break; 
case "image": 
//图文混合的消息 具体格式请见官方API“回复图文消息”  
break; 
} 

System.Web.HttpContext.Current.Response.Write(resxml); 
WriteToDB(requestXML, resxml, mi.pid); 
} 
catch (Exception ex) 
{ 
//WriteTxt("异常：" + ex.Message + "Struck:" + ex.StackTrace.ToString()); 
//wx_logs.MyInsert("异常：" + ex.Message + "Struck:" + ex.StackTrace.ToString()); 
} 
} 

 
/// <summary> 
/// unix时间转换为datetime 
/// </summary> 
/// <param name="timeStamp"></param> 
/// <returns></returns> 
private DateTime UnixTimeToTime(string timeStamp) 
{ 
DateTime dtStart = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1)); 
long lTime = long.Parse(timeStamp + "0000000"); 
TimeSpan toNow = new TimeSpan(lTime); 
return dtStart.Add(toNow); 
} 

 
/// <summary> 
/// datetime转换为unixtime 
/// </summary> 
/// <param name="time"></param> 
/// <returns></returns> 
private int ConvertDateTimeInt(System.DateTime time) 
{ 
System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1)); 
return (int)(time - startTime).TotalSeconds; 
} 

 
/// <summary> 
/// 调用百度地图，返回坐标信息 
/// </summary> 
/// <param name="y">经度</param> 
/// <param name="x">纬度</param> 
/// <returns></returns> 
public string GetMapInfo(string x, string y) 
{ 
try
{ 
string res = string.Empty; 
string parame = string.Empty; 
string url = "http://maps.googleapis.com/maps/api/geocode/xml"; 

parame = "latlng=" + x + "," + y + "&language=zh-CN&sensor=false";//此key为个人申请 
res = webRequestPost(url, parame); 

XmlDocument doc = new XmlDocument(); 
doc.LoadXml(res); 

XmlElement rootElement = doc.DocumentElement; 
string Status = rootElement.SelectSingleNode("status").InnerText; 

if (Status == "OK") 
{ 
//仅获取城市 
XmlNodeList xmlResults = rootElement.SelectSingleNode("/GeocodeResponse").ChildNodes; 
for (int i = 0; i < xmlResults.Count; i++) 
{ 
XmlNode childNode = xmlResults[i]; 
if (childNode.Name == "status") { 
continue; 
} 
string city = "0"; 
for (int w = 0; w < childNode.ChildNodes.Count; w++) 
{ 
for (int q = 0; q < childNode.ChildNodes[w].ChildNodes.Count; q++) 
{ 
XmlNode childeTwo = childNode.ChildNodes[w].ChildNodes[q]; 
if (childeTwo.Name == "long_name") 
{ 
city = childeTwo.InnerText; 
} 
else if (childeTwo.InnerText == "locality") 
{ 
return city; 
} 
} 
} 
return city; 
} 
} 
} 
catch (Exception ex) 
{ 
//WriteTxt("map异常:" + ex.Message.ToString() + "Struck:" + ex.StackTrace.ToString()); 
return "0"; 
}  
return "0"; 
} 

 
/// <summary> 
/// Post 提交调用抓取 
/// </summary> 
/// <param name="url">提交地址</param> 
/// <param name="param">参数</param> 
/// <returns>string</returns> 
public string webRequestPost(string url, string param) 
{ 
byte[] bs = System.Text.Encoding.UTF8.GetBytes(param); 
HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url + "?" + param); 
req.Method = "Post"; 
req.Timeout = 120 * 1000; 
req.ContentType = "application/x-www-form-urlencoded;"; 
req.ContentLength = bs.Length; 

using (Stream reqStream = req.GetRequestStream()) 
{ 
reqStream.Write(bs, 0, bs.Length); 
reqStream.Flush(); 
} 

using (WebResponse wr = req.GetResponse()) 
{ 
//在这里对接收到的页面内容进行处理 
Stream strm = wr.GetResponseStream(); 
StreamReader sr = new StreamReader(strm, System.Text.Encoding.UTF8); 

string line; 
System.Text.StringBuilder sb = new System.Text.StringBuilder(); 
while ((line = sr.ReadLine()) != null) 
{ 
sb.Append(line + System.Environment.NewLine); 
} 
sr.Close(); 
strm.Close(); 
return sb.ToString(); 
} 
} 

/// <summary> 
/// 将本次交互信息保存至数据库中 
/// </summary> 
/// <param name="requestXML"></param> 
/// <param name="_xml"></param> 
/// <param name="_pid"></param> 
private void WriteToDB(RequestXML requestXML, string _xml, int _pid) 
{ 
WeiXinMsg wx = new WeiXinMsg(); 
wx.FromUserName = requestXML.FromUserName; 
wx.ToUserName = requestXML.ToUserName; 
wx.MsgType = requestXML.MsgType; 
wx.Msg = requestXML.Content; 
wx.Creatime = requestXML.CreateTime; 
wx.Location_X = requestXML.Location_X; 
wx.Location_Y = requestXML.Location_Y; 
wx.Label = requestXML.Label; 
wx.Scale = requestXML.Scale; 
wx.PicUrl = requestXML.PicUrl; 
wx.reply = _xml; 
wx.pid = _pid; 
try
{ 
wx.Add(); 
} 
catch (Exception ex) 
{ 
//wx_logs.MyInsert(ex.Message); 
//ex.message; 
} 
} 
}

响应类MODEL

复制代码 代码如下:
#region 微信请求类 RequestXML 
/// <summary> 
/// 微信请求类 
/// </summary> 
public class RequestXML 
{ 
private string toUserName = ""; 
/// <summary> 
/// 消息接收方微信号，一般为公众平台账号微信号 
/// </summary> 
public string ToUserName 
{ 
get { return toUserName; } 
set { toUserName = value; } 
} 

private string fromUserName = ""; 
/// <summary> 
/// 消息发送方微信号 
/// </summary> 
public string FromUserName 
{ 
get { return fromUserName; } 
set { fromUserName = value; } 
} 

private string createTime = ""; 
/// <summary> 
/// 创建时间 
/// </summary> 
public string CreateTime 
{ 
get { return createTime; } 
set { createTime = value; } 
} 

private string msgType = ""; 
/// <summary> 
/// 信息类型 地理位置:location,文本消息:text,消息类型:image 
/// </summary> 
public string MsgType 
{ 
get { return msgType; } 
set { msgType = value; } 
} 

private string content = ""; 
/// <summary> 
/// 信息内容 
/// </summary> 
public string Content 
{ 
get { return content; } 
set { content = value; } 
} 

private string location_X = ""; 
/// <summary> 
/// 地理位置纬度 
/// </summary> 
public string Location_X 
{ 
get { return location_X; } 
set { location_X = value; } 
} 

private string location_Y = ""; 
/// <summary> 
/// 地理位置经度 
/// </summary> 
public string Location_Y 
{ 
get { return location_Y; } 
set { location_Y = value; } 
} 

private string scale = ""; 
/// <summary> 
/// 地图缩放大小 
/// </summary> 
public string Scale 
{ 
get { return scale; } 
set { scale = value; } 
} 

private string label = ""; 
/// <summary> 
/// 地理位置信息 
/// </summary> 
public string Label 
{ 
get { return label; } 
set { label = value; } 
} 

private string picUrl = ""; 
/// <summary> 
/// 图片链接，开发者可以用HTTP GET获取 
/// </summary> 
public string PicUrl 
{ 
get { return picUrl; } 
set { picUrl = value; } 
} 
} 
#endregion