百度API調用實例

今天依據需求要從百度API中取出一些數據。這些操作包含：將坐標轉換成百度坐標。依據轉換的百度坐標進行特定的查詢。

有需求的收藏下，免得下次手寫浪費時間。

涉及到的操作有：JSON格式的字符解析。HTTP請求和獲得請求數據。文件流的寫入和讀出等等。

奉上源碼。共享：

首先是入口函數：

static void Main(string[] args)
        {
            Console.WriteLine("坐標轉換。信息查詢開始......");
            string oFile = "C:\\Users\\MisterHu\\Desktop\\點加屬性\\聚類點.txt";
            string iFile = "C:\\Users\\MisterHu\\Desktop\\點加屬性\\result.txt";

            List<string> tCoords = new List<string>();//存轉換前坐標
            List<string> cvtCoords = new List<string>();//存轉換后坐標
            List<string> rstQuery = new List<string>();//存查詢結果

            string sInfo; //暫時字符變量
            StreamReader sr = new StreamReader(oFile, Encoding.Default);
            while ((sInfo = sr.ReadLine()) != null)
            {
                tCoords.Add(sInfo.Substring(sInfo.IndexOf(',')+1));
            }
            sr.Close();

            //轉換成百度坐標。然后存放到List中
            BaiDuAPI.CoordConvert(tCoords, cvtCoords);

            //從List中取出每一個坐標。然后調用API
            BaiDuAPI.PlaceAPI(cvtCoords, rstQuery);

            //寫入文件。
            String strLine = null;         
            for (int i = 1; i <= 1000;++i )
            {
                strLine += i.ToString() + "," + tCoords[i - 1] + rstQuery[i - 1] + "\r\n";           
            }

            FileStream.WriteInFile(strLine, iFile);
            Console.WriteLine("轉換，獲取，完畢！");
        }

字符串輸入輸出到文件：

 //輸入輸出字符到文件里
    public static class FileStream
    {
        public static void ReadFormFile(string path)
        {

        }

        public static void WriteInFile(string content,string path)
        {
            string iFile = "D:\\temp.txt";
            if (path == null) path = iFile;
            
            StreamWriter sw = new StreamWriter(path);
            sw.Write(content);
            sw.Flush();
            sw.Close();
        }
    }

核心類，細致看，依據自己的需求能夠做適當的改動：

//處理API請求
    public static class BaiDuAPI
    {
        public static void CoordConvert(List<string> src,List<string> des)
        {
            StringBuilder RequestURL = new StringBuilder();
            StringBuilder coordStr = new StringBuilder();
            string arg1 = "http://api.map.baidu.com/geoconv/v1/?
coords=";
            string arg2 = "&from=1&to=5&ak=IC96AbO521APtmpsaR9xCMqo";

            string result = null;
            int count = src.Count;

            for (int i = 0; i < count; ++i)
            {
                if ((i+1)%100 != 0 && i != count - 1) //將100個數據加進去
                {
                    coordStr.Append(src[i]);
                    coordStr.Append(";");
                    continue;
                }
                else if ((i + 1) % 100 == 0 || i == count - 1) //處理不足100個數據和第100個數據
                {
                   coordStr.Append(src[i]);
                }

                RequestURL.Append(arg1);
                RequestURL.Append(coordStr);
                RequestURL.Append(arg2);
                result = HttpGet(RequestURL.ToString());
                
                //處理返回的結果
                DoJsonCoords(result,des);

                result = null;
                RequestURL.Clear();
                coordStr.Clear();
            }
             
        }

        public static void DoJsonCoords(string result, List<string> des)
        {
            if (result == "" || result == null) return;

            JsonCoord jsonCoord = JSON.ParseJson<JsonCoord>(result);
            
            List<Coord> coord = jsonCoord.result;
            string temp = null;
            foreach (Coord crd in coord)
            {
                temp = crd.y.ToString() + "," + crd.x.ToString();
                des.Add(temp);
            }
        }

        /// <summary>
        /// 返回結果字符串
        /// </summary>
        public static void PlaceAPI(List<string> des,List<string> rst)
        {
            //購物//教育//景點//企業//小區
            List<string> query = new List<string>{ "購物", "教育","景點","企業", "小區"};
            StringBuilder RequestURL = new StringBuilder();
            StringBuilder tempQuery = new StringBuilder();
            string arg1 = "http://api.map.baidu.com/place/v2/search?
ak=IC96AbO521APtmpsaR9xCMqo&output=json&query=";
            string arg2 = "&page_size=1&page_num=0&scope=1&location=";
            string arg3 = "&radius=1000";

            string jsonResult = null;
            string tStr = null;
            int num;
            foreach (string str in des)
            {
                for (int i = 0; i < 5;++i )
                {
                    tempQuery.Append(HttpUtility.UrlEncode(query[i]));
                    tempQuery.Append(arg2);
                    tempQuery.Append(str);
                    tempQuery.Append(arg3);

                    RequestURL.Append(arg1);
                    RequestURL.Append(tempQuery.ToString());

                    jsonResult = HttpGet(RequestURL.ToString());
                    num = DoJsonPlace(jsonResult);
                    tStr += "," + query[i] + num.ToString();

                    tempQuery.Clear();
                    RequestURL.Clear();
                }
                rst.Add(tStr);
                Console.WriteLine(tStr);
                tStr = null;
            }
        }

        public static int DoJsonPlace(string result)
        {
            if (result == "" || result == null) return -1;

            Place place = JSON.ParseJson<Place>(result);

            return place.total;
        }

        /// <summary>
        /// 通過url獲取返回來的字符串
        /// </summary>
        private static string HttpGet(string requestURL)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(requestURL.ToString());
            request.Method = "GET";
            request.ServicePoint.Expect100Continue = false;
            request.Method = "GET";
            request.KeepAlive = true;
            request.UserAgent = ".NET Framework BsiDuAPI Client";
            request.ContentType = "application/x-www-form-urlencoded;charset=utf-8";

            HttpWebResponse response = null;
            try
            {
                response = (HttpWebResponse)request.GetResponse();
            }
            catch (WebException webEx)
            {
                if (webEx.Status == WebExceptionStatus.Timeout)
                {
                    response = null;
                }
                Console.WriteLine(webEx.Status.ToString());
            }

            if (response != null)
            {
                if (response.CharacterSet != null)
                {
                    Encoding encoding = Encoding.GetEncoding(response.CharacterSet);
                    return GetResponseAsString(response, encoding);
                }
                else
                {
                    return string.Empty;
                }
            }
            else
            {
                return string.Empty;
            }
        }

        private static string GetResponseAsString(HttpWebResponse response, Encoding encoding)
        {
            StringBuilder result = new StringBuilder();
            Stream stream = null;
            StreamReader reader = null;

            try
            {
                // 以字符流的方式讀取HTTP響應
                stream = response.GetResponseStream();
                reader = new StreamReader(stream, encoding);

                // 每次讀取不大於256個字符，並寫入字符串
                char[] buffer = new char[256];
                int readBytes = 0;
                while ((readBytes = reader.Read(buffer, 0, buffer.Length)) > 0)
                {
                    result.Append(buffer, 0, readBytes);
                }
            }
            catch (WebException webEx)
            {
                if (webEx.Status == WebExceptionStatus.Timeout)
                {
                    result = new StringBuilder();
                }
            }
            finally
            {
                // 釋放資源
                if (reader != null) reader.Close();
                if (stream != null) stream.Close();
                if (response != null) response.Close();
            }

            return result.ToString();
        }
    }

解析Json的類，沒什么好說的直接copy：

//Json解析
    public static class JSON
    {
        /// <summary>
        /// 將Json反序列化為T對象
        /// </summary>
        public static T ParseJson<T>(string jsonString)
        {
            using (var ms = new MemoryStream(Encoding.UTF8.GetBytes(jsonString)))
            {
                return (T)new DataContractJsonSerializer(typeof(T)).ReadObject(ms);
            }
        }

        /// <summary>
        /// 將對象序列化為Json
        /// </summary>
        public static string Stringify(object jsonObject)
        {
            using (var ms = new MemoryStream())
            {
                new DataContractJsonSerializer(jsonObject.GetType()).WriteObject(ms, jsonObject);
                return Encoding.UTF8.GetString(ms.ToArray());
            }
        }
    }

    //序列化對象
    [DataContract]
    public class Coord
    {
        [DataMember]
        public float x {get;set;}

        [DataMember]
        public float y {get;set;}
    }

    [DataContract]
    public class JsonCoord
    {
        [DataMember]
        public int status { get; set; }

        [DataMember]
        public List<Coord> result { get; set; }
    }

    [DataContract]
    public class Place
    {
        [DataMember]
        public int status { get; set; }

        [DataMember]
        public string message { get; set; }

        [DataMember]
        public int total { get; set; }

        //結果沒用，不獲取。
        //[DataMember(IsRequired = false)]
        //public string results { get; set; }
    }

注意。序列化對象類的寫法，值得提出的一點是當不須要某個節點時。能夠不用寫出來，就像results一樣。由於我的需求根本不關心當中的內容。

最后，附上源碼文件：http://download.csdn.net/detail/z702143700/8777263