using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Reflection;
using System.Text;

namespace Helper
{
  public static class JsonHelper
    {
        /// <summary>
    /// List转成json
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="jsonName"></param>
    /// <param name="list"></param>
    /// <returns></returns>
    public static string ListToJson<T>(IList<T> list, string jsonName)
    {

        //检查实体集合不能为空
        //if (list == null || list.Count < 1)
        //{
        //    //throw new Exception("需转换的集合为空");
        //    return null;
        //}
        StringBuilder Json = new StringBuilder();
        if (string.IsNullOrEmpty(jsonName))
            jsonName = list[0].GetType().Name;
        Json.Append("{\"" + jsonName + "\":[");
        if (list.Count > 0)
        {
            for (int i = 0; i < list.Count; i++)
            {
                T obj = Activator.CreateInstance<T>();
                PropertyInfo[] pi = obj.GetType().GetProperties();
                Json.Append("{");
                for (int j = 0; j < pi.Length; j++)
                {
                    
                        Type type = pi[j].GetValue(list[i], null).GetType();
                        Json.Append("\"" + pi[j].Name.ToString() + "\":" + StringFormat(pi[j].GetValue(list[i], null).ToString(), type));
                    
                   
                    if (j < pi.Length - 1)
                    {
                        Json.Append(",");
                    }
                }
                Json.Append("}");
                if (i < list.Count - 1)
                {
                    Json.Append(",");
                }
            }
        }
        Json.Append("]}");
        return Json.ToString();
    }


      /// <summary>
      /// 转换成JArray
      /// </summary>
      /// <typeparam name="T"></typeparam>
      /// <param name="list"></param>
      /// <param name="jsonName"></param>
      /// <returns></returns>
    public static string ListToJArray<T>(IList<T> list)
    {

        
        StringBuilder Json = new StringBuilder();
        
        Json.Append("[");
        if (list.Count > 0)
        {
            for (int i = 0; i < list.Count; i++)
            {
                T obj = Activator.CreateInstance<T>();
                PropertyInfo[] pi = obj.GetType().GetProperties();
                Json.Append("{");
                for (int j = 0; j < pi.Length; j++)
                {

                    Type type = pi[j].GetValue(list[i], null).GetType();
                    Json.Append("\"" + pi[j].Name.ToString() + "\":" + StringFormat(pi[j].GetValue(list[i], null).ToString(), type));


                    if (j < pi.Length - 1)
                    {
                        Json.Append(",");
                    }
                }
                Json.Append("}");
                if (i < list.Count - 1)
                {
                    Json.Append(",");
                }
            }
        }
        Json.Append("]");
        return Json.ToString();
    }
   
    /// <summary>
    /// List转成json
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="list"></param>
    /// <returns></returns>
    public static string ListToJson<T>(IList<T> list)
    {
        object obj = list[0];
        return ListToJson<T>(list, obj.GetType().Name);
    }
 
    /// <summary>
    /// 对象转换为Json字符串
    /// </summary>
    /// <param name="jsonObject">对象</param>
    /// <returns>Json字符串</returns>
    public static string ToJson(object jsonObject)
    {
        try
        {
            StringBuilder jsonString = new StringBuilder();
            jsonString.Append("{");
            PropertyInfo[] propertyInfo = jsonObject.GetType().GetProperties();
            for (int i = 0; i < propertyInfo.Length; i++)
            {
                object objectValue = http://www.mamicode.com/propertyInfo[i].GetGetMethod().Invoke(jsonObject, null);
                if (objectValue =http://www.mamicode.com/= null)
                {
                    continue;
                }
                StringBuilder value = new StringBuilder();
                if (objectValue is DateTime || objectValue is Guid || objectValue is TimeSpan)
                {
                    value.Append("\"" + objectValue.ToString() + "\"");
                }
                else if (objectValue is string)
                {
                    value.Append("\"" + objectValue.ToString() + "\"");
                }
                else if (objectValue is IEnumerable)
                {
                    value.Append(ToJson((IEnumerable)objectValue));
                }
                else
                {
                    value.Append("\"" + objectValue.ToString() + "\"");
                }
                jsonString.Append("\"" + propertyInfo[i].Name + "\":" + value + ","); 
            }
            return jsonString.ToString().TrimEnd(‘,‘) + "}";
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
 
    /// <summary>
    /// 对象集合转换Json
    /// </summary>
    /// <param name="array">集合对象</param>
    /// <returns>Json字符串</returns>
    public static string ToJson(IEnumerable array)
    {
        string jsonString = "[";
        foreach (object item in array)
        {
            jsonString += ToJson(item) + ",";
        }
        jsonString.Remove(jsonString.Length - 1, jsonString.Length);
        return jsonString + "]";
    }
 
    /// <summary>
    /// 普通集合转换Json
    /// </summary>
    /// <param name="array">集合对象</param>
    /// <returns>Json字符串</returns>
    public static string ToArrayString(IEnumerable array)
    {
        string jsonString = "[";
        foreach (object item in array)
        {
            jsonString = ToJson(item.ToString()) + ",";
        }
        jsonString.Remove(jsonString.Length - 1, jsonString.Length);
        return jsonString + "]";
    }
 
    /// <summary>
    /// Datatable转换为Json
    /// </summary>
    /// <param name="table">Datatable对象</param>
    /// <returns>Json字符串</returns>
    public static string ToJson(DataTable dt)
    {
        StringBuilder jsonString = new StringBuilder();
        jsonString.Append("[");
        DataRowCollection drc = dt.Rows;
        for (int i = 0; i < drc.Count; i++)
        {
            jsonString.Append("{");
            for (int j = 0; j < dt.Columns.Count; j++)
            {
                string strKey = dt.Columns[j].ColumnName;
                string strValue =http://www.mamicode.com/ drc[i][j].ToString();
                Type type = dt.Columns[j].DataType;
                jsonString.Append("\"" + strKey + "\":");
                strValue = StringFormat(strValue, type);
                if (j < dt.Columns.Count - 1)
                {
                    jsonString.Append(strValue + ",");
                }
                else
                {
                    jsonString.Append(strValue);
                }
            }
            jsonString.Append("},");
        }
        jsonString.Remove(jsonString.Length - 1, 1);
        jsonString.Append("]");
        return jsonString.ToString();
    }
 
    /// <summary>
    /// DataTable转成Json
    /// </summary>
    /// <param name="jsonName"></param>
    /// <param name="dt"></param>
    /// <returns></returns>
    public static string ToJson(DataTable dt, string jsonName)
    {
        StringBuilder Json = new StringBuilder();
        if (string.IsNullOrEmpty(jsonName))
            jsonName = dt.TableName;
        Json.Append("{\"" + jsonName + "\":[");
        if (dt.Rows.Count > 0)
        {
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                Json.Append("{");
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    Type type = dt.Rows[i][j].GetType();
                    Json.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":" + StringFormat(dt.Rows[i][j].ToString(), type));
                    if (j < dt.Columns.Count - 1)
                    {
                        Json.Append(",");
                    }
                }
                Json.Append("}");
                if (i < dt.Rows.Count - 1)
                {
                    Json.Append(",");
                }
            }
        }
        Json.Append("]}");
        return Json.ToString();
    }
 
    /// <summary>
    /// DataReader转换为Json
    /// </summary>
    /// <param name="dataReader">DataReader对象</param>
    /// <returns>Json字符串</returns>
    public static string ToJson(IDataReader dataReader)
    {
        StringBuilder jsonString = new StringBuilder();
        jsonString.Append("[");
 
        while (dataReader.Read())
        {
            jsonString.Append("{");
            for (int i = 0; i < dataReader.FieldCount; i++)
            {
                Type type = dataReader.GetFieldType(i);
                string strKey = dataReader.GetName(i);
                string strValue =http://www.mamicode.com/ dataReader[i].ToString();
                jsonString.Append("\"" + strKey + "\":");
                strValue = StringFormat(strValue, type);
                if (i < dataReader.FieldCount - 1)
                {
                    jsonString.Append(strValue + ",");
                }
                else
                {
                    jsonString.Append(strValue);
                }
            }
            jsonString.Append("},");
        }
        dataReader.Close();
        jsonString.Remove(jsonString.Length - 1, 1);
        jsonString.Append("]");
        if (jsonString.Length == 1)
        {
            return "[]";
        }
        return jsonString.ToString();
    }
 
    /// <summary>
    /// DataSet转换为Json
    /// </summary>
    /// <param name="dataSet">DataSet对象</param>
    /// <returns>Json字符串</returns>
    public static string ToJson(DataSet dataSet)
    {
        string jsonString = "{";
        foreach (DataTable table in dataSet.Tables)
        {
            jsonString += "\"" + table.TableName + "\":" + ToJson(table) + ",";
        }
        jsonString = jsonString.TrimEnd(‘,‘);
        return jsonString + "}";
    }
 
    /// <summary>
    /// 过滤特殊字符
    /// </summary>
    /// <param name="s"></param>
    /// <returns></returns>
    private static string String2Json(String s)
    {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < s.Length; i++)
        {
            char c = s.ToCharArray()[i];
            switch (c)
            {
                case ‘\"‘:
                    sb.Append("\\\""); break;
                //case ‘//‘:
                //    sb.Append("////"); break;
                //case ‘/‘:
                //    sb.Append("///"); break;
                case ‘\b‘:
                    sb.Append("\\b"); break;
                case ‘\f‘:
                    sb.Append("\\f"); break;
                case ‘\n‘:
                    sb.Append("\\n"); break;
                case ‘\r‘:
                    sb.Append("\\r"); break;
                case ‘\t‘:
                    sb.Append("\\t"); break;
                default:
                    sb.Append(c); break;
            }
        }
        return sb.ToString();
    }
 
    /// <summary>
    /// 格式化字符型、日期型、布尔型
    /// </summary>
    /// <param name="str"></param>
    /// <param name="type"></param>
    /// <returns></returns>
    private static string StringFormat(string str, Type type)
    {
        if (type != typeof(string) && string.IsNullOrEmpty(str))
        {
            str = "\"" + str + "\"";
        }
        else if (type == typeof(string))
        {
            str = String2Json(str);
            str = "\"" + str + "\"";
        }
        else if (type == typeof(DateTime))
        {
            str = "\"" + str.Split(‘ ‘)[0] + "\"";
        }
        else if (type == typeof(bool))
        {
            str = str.ToLower();
        }
 
        return str;
    }
    }
}