内网公告牌获取天气信息解决方案(C# WebForm)

需求：内网公告牌能够正确显示未来三天的天气信息

本文关键字：C#/WebForm/Web定时任务/Ajax跨域

规划：

1、天定时读取百度接口获取天气信息并存储至Txt文档；

2、示牌开启时请求WebService，获取天气信息；

解决方案：

1、在Global.asax中能够配置整个工程不同情况下触发的事件，其中 Application_Start方法是在iis启动本项目时就开始的进程。在本方法下写入定时从百度读取天气信息的代码，调用的WebService代码在下面的第2部分：

　　

protected void Application_Start(object sender, EventArgs e)

        {

            String NowTime = DateTime.Now.ToString("hh24:mi:ss");

            //定时任务

            //if (NowTime == "")

            //{

            WebService1 ws = new WebService1();

            ws.GetBaiduWeather();

            //}

            //每天执行一次

            Timer t = new Timer(60 * 60 * 24 * 1000);

            t.Elapsed += new System.Timers.ElapsedEventHandler(DownLoadWeather);

            t.Enabled = true;

        }

　　WebService代码如下

[WebMethod]

        public void GetBaiduWeather()

        {

            string callback = HttpContext.Current.Request["jsoncallback"];

            WeatherDownload.getrequest();

            HttpContext.Current.Response.Write(callback +

                "({result:'true'})");

            HttpContext.Current.Response.End();

        }

　　调用百度天气接口存储数据的代码如下所示，其存储的结果是Json字符串。

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Net;

using System.IO;

using System.Text;

using System.Text.RegularExpressions;

namespace WebService

{

    public static class WeatherDownload

    {

        public static string url = "http://apis.baidu.com/apistore/weatherservice/recentweathers";

        public static string param = "cityname=石家庄&cityid=101090101";

        /// <summary>

        /// 查询天气情况

        /// </summary>

        /// <param name="url"></param>

        public static void getrequest()

        {

            string strURL = url + '?' + param;

            System.Net.HttpWebRequest request;

            request = (System.Net.HttpWebRequest)WebRequest.Create(strURL);

            request.Method = "GET";

            request.Headers.Add("apikey", "在百度上申请的开发者个人码");

            System.Net.HttpWebResponse response;

            response = (System.Net.HttpWebResponse)request.GetResponse();

            System.IO.Stream s;

            s = response.GetResponseStream();

            string StrDate = "";

            string strValue = "";

            StreamReader Reader = new StreamReader(s, Encoding.UTF8);

            while ((StrDate = Reader.ReadLine()) != null)

            {

                strValue += StrDate + "\r\n";

            }

            if (File.Exists(System.AppDomain.CurrentDomain.BaseDirectory + "\\" + DateTime.Now.ToString("yyyyMMdd") + ".txt"))

            {

            }

            else

            {

                using (File.Create(System.AppDomain.CurrentDomain.BaseDirectory + "\\" + DateTime.Now.ToString("yyyyMMdd") + ".txt"))

                {

                }

            }

            FileStream fs = new FileStream(System.AppDomain.CurrentDomain.BaseDirectory + "\\" + DateTime.Now.ToString("yyyyMMdd") + ".txt", FileMode.Create);

            StreamWriter sw = new StreamWriter(fs);

            String w = UnicodeToStr(strValue);

            sw.Write(w);

            sw.Flush();

            sw.Close();

            fs.Close();

        }

        /// <summary>

        /// 编码为汉字

        /// </summary>

        /// <param name="str"></param>

        /// <returns></returns>

        public static string UnicodeToStr(string str)

        {

            string outStr = "";

            Regex reg = new Regex(@"(?i)\\u([0-9a-f]{4})");

            outStr = reg.Replace(str, delegate(Match m1)

            {

                return ((char)Convert.ToInt32(m1.Groups[1].Value, 16)).ToString();

            });

            return outStr;

        }

    }

}

2、页面请求WebService获取天气数据

　　此处使用的Ajax请求，特征是跨域请求，当时出的问题比较多，一篇很好的参考文献如下（http://www@suchso@com/projecteactual/jquery-ajax-parsererror-was-not-called.html）（请把@改为.）

$.ajax({
　　　　　　　　//111.111.111.111为实际

            url: "http://111.111.111.111/WebService1.asmx/GetWeather?jsoncallback=?",

            dataType: "jsonp",

            success: OnSuccess,

            error: OnError

        });

        //}

        function OnSuccess(json) {

            $("#today").text(json.retData.today.curTemp.toString())

            $("#today_wth").text(json.retData.today.type.toString())

        }

        function OnError(XMLHttpRequest, textStatus, errorThrown) {

            alert("Something error");

        }

　　对应的WebService代码如下

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.Services;

using System.IO;

using System.Text;

namespace WebService

{

    [WebService(Namespace = "http://tempuri.org/")]

    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]

    [System.ComponentModel.ToolboxItem(false)]

    public class WebService1 : System.Web.Services.WebService

    {

        [WebMethod]

        public void GetWeather()

        {

            String sr = File.ReadAllText(System.AppDomain.CurrentDomain.BaseDirectory + DateTime.Now.ToString("yyyyMMdd") + ".txt", UnicodeEncoding.GetEncoding("UTF-8"));

            string callback = HttpContext.Current.Request["jsoncallback"];

            HttpContext.Current.Response.Write(callback + "(" + sr + ")");

        }

    }

}

内网公告牌获取天气信息解决方案(C# WebForm)的相关教程结束。