每次写博客，第一句话都是这样的：程序员很苦逼，除了会写程序，还得会写博客！当然，希望将来的一天，某位老板看到此博客，给你的程序员职工加点薪资吧！因为程序员的世界除了苦逼就是沉默。我眼中的程序员大多都不爱说话，默默承受着编程的巨大压力，除了技术上的交流外，他们不愿意也不擅长和别人交流，更不乐意任何人走进他们的内心！
最近悟出来一个道理，在这儿分享给大家：学历代表你的过去，能力代表你的现在，学习代表你的将来。我们都知道计算机技术发展日新月异，速度惊人的快，你我稍不留神，就会被慢慢淘汰！因此：每日不间断的学习是避免被淘汰的不二法宝。
当然，题外话说多了，咱进入正题！
引言
随着近年来Android和IOS的流行，越来越多的项目需要处理JSON格式数据，因此：学习JSON相关知识成为了程序员必不可少的一门学术。
本文以C#语言，针对JSON入手，简要探讨下JSON数据的处理。
误区
1、很多类型数据都可以转化为JSON，譬如：List集合转化为Json、DataTable转化为Json、XML转化为Json等
2、但是如果反过来转化是否可以呢？譬如：JSON字符串转为DataTable，转为XML，转为LIST等？
在此：我给的答案是(1)中转化不会出现问题，(2)中转化就不一定完全正确了。究其原因，是因为JSON格式多种多样，其他数据类型则对结构有所要求！
例如：DataTable表结构，由列和行组成，稍微复杂的JSON串转化为DataTable就会出错。
在此分享一个JSON转为DataTable的方法，大家自行实验，而实验的结果是运行抛出异常，运行报错。代码如下：
protected void Page_Load(object sender, EventArgs e)
{
string s = @"{'calledList':[{'duration':0,'id':1,'isCalled':true,'isDel':false,'lDate':1423300697418,'name':'杨秀英','number':'13087237088'},{'duration':0,'id':3,'isCalled':true,'isDel':false,'lDate':1473300711441,'name':'付五爱','number':'15898579759'},{'duration':0,'id':4,'isCalled':true,'isDel':false,'lDate':1473301518397,'name':'梁清华','number':'12467320223'},{'duration':0,'id':5,'isCalled':true,'isDel':false,'lDate':1423301571910,'name':'莫春梅','number':'13273209401'}],'counterid':'A-HN-CS-0731-CT023'}";
DataTable dt = JsonToDataTable(s);
} /// <summary>
/// 将json转换为DataTable
/// </summary>
/// <param name="strJson">得到的json 注意：对JSON的格式有要求 否则异常</param>
/// <returns></returns>
public DataTable JsonToDataTable(string strJson)
{
//转换json格式
strJson = strJson.Replace(",\"", "*\"").Replace("\":", "\"#").ToString();
//取出表名
var rg = new Regex(@"(?<={)[^:]+(?=:\[)", RegexOptions.IgnoreCase);
string strName = rg.Match(strJson).Value;
DataTable tb = null;
//去除表名
strJson = strJson.Substring(strJson.IndexOf("[") + );
strJson = strJson.Substring(, strJson.IndexOf("]")); //获取数据
rg = new Regex(@"(?<={)[^}]+(?=})");
MatchCollection mc = rg.Matches(strJson);
for (int i = ; i < mc.Count; i++)
{
string strRow = mc[i].Value;
string[] strRows = strRow.Split('*'); //创建表
if (tb == null)
{
tb = new DataTable();
tb.TableName = strName;
foreach (string str in strRows)
{
var dc = new DataColumn();
string[] strCell = str.Split('#'); if (strCell[].Substring(, ) == "\"")
{
int a = strCell[].Length;
dc.ColumnName = strCell[].Substring(, a - );
}
else
{
dc.ColumnName = strCell[];
}
tb.Columns.Add(dc);
}
tb.AcceptChanges();
} //增加内容
DataRow dr = tb.NewRow();
for (int r = ; r < strRows.Length; r++)
{
dr[r] = strRows[r].Split('#')[].Trim().Replace("，", ",").Replace("：", ":").Replace("\"", "");
}
tb.Rows.Add(dr);
tb.AcceptChanges();
} return tb;
}
由上实例可知：字符串s的结构要比单纯的DataTable复杂多了，因此：要想将字符串s转为DataTable是行不通的。
那么，我们应当怎样转化JSON呢？在这里给大家介绍一个通用的方法，如下：
不管多么复杂的JSON串，其结构都是有规律可循的，上述中的s字符串无非是由：calledlist集合和属性counterid组成，因此，我们可根据分析的JSON结构，创建如下相关类：
public class callBackList
{
public string counterid { get; set; }
public List<calledList> calledList { get; set; }
} public class calledList
{
public int duration { get; set; }
public int id { get; set; }
public bool isCalled { get; set; }
public bool isDel { get; set; }
public long lDate { get; set; }
public string name { get; set; }
public string number { get; set; }
}
在此：会用到一个通用的方法如下：
public T JsonDeserialize<T>(string jsonString)
{
return JsonConvert.DeserializeObject<T>(jsonString);
}
调用实例如下：
protected void Page_Load(object sender, EventArgs e)
{
string s = @"{'calledList':[{'duration':0,'id':1,'isCalled':true,'isDel':false,'lDate':1473300697418,'name':'杨秀英','number':'13087237088'},{'duration':0,'id':3,'isCalled':true,'isDel':false,'lDate':1473300711441,'name':'付五爱','number':'15898579759'},{'duration':0,'id':4,'isCalled':true,'isDel':false,'lDate':1473301518397,'name':'梁清华','number':'13467320223'},{'duration':0,'id':5,'isCalled':true,'isDel':false,'lDate':1473301571910,'name':'莫春梅','number':'13873209401'}],'counterid':'A-HN-CS-0731-CT023'}";
callBackList O = JsonDeserialize<callBackList>(s);
var Ary = O.calledList;
string counterId = O.counterid;
foreach (var A in Ary)
{
Response.Write(A.name);
}
}
小虎斑们可以自行运行，在此不作过多解释。
刚才上文中提到：其他类型转为JSON都是行的通的，JSON转其他类型不一定行的通，除非JSON结构和所要转为的数据类型一致，否则就会转化出错。
那么，我们如何将其他类型转为JSON字符串呢？
在此：首先贴出一个通用的方法如下：
public class JsonHelper
{
public static string JsonSerializer<T>(T t)
{ DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(T));
MemoryStream ms = new MemoryStream();
ser.WriteObject(ms, t);
string jsonString = Encoding.UTF8.GetString(ms.ToArray());
ms.Close(); //替换Json的Date字符串
string p = @"\\/Date\((\d+)\+\d+\)\\/";
MatchEvaluator matchEvaluator = new MatchEvaluator(ConvertJsonDateToDateString);
Regex reg = new Regex(p);
jsonString = reg.Replace(jsonString, matchEvaluator); return jsonString; } public static T JsonDeserialize<T>(string jsonString)
{
return JsonConvert.DeserializeObject<T>(jsonString);
} /// <summary>
/// 将Json序列化的时间由/Date(1294499956278+0800)转为字符串
/// </summary>
private static string ConvertJsonDateToDateString(Match m)
{ string result = string.Empty; DateTime dt = new DateTime(, , ); dt = dt.AddMilliseconds(long.Parse(m.Groups[].Value)); dt = dt.ToLocalTime(); result = dt.ToString("yyyy-MM-dd HH:mm:ss"); return result; } /// <summary> /// 将时间字符串转为Json时间 /// </summary> private static string ConvertDateStringToJsonDate(Match m)
{ string result = string.Empty; DateTime dt = DateTime.Parse(m.Groups[].Value); dt = dt.ToUniversalTime(); TimeSpan ts = dt - DateTime.Parse("1970-01-01"); result = string.Format("\\/Date({0}+0800)\\/", ts.TotalMilliseconds); return result; }
}
上述方法：JsonSerializer<T>(T t)中的T就是通用类型，可以为DataTable XML OBJECT等
至于其他方法，都是针对专门的类型就行构造的，如下
public class JsonHelper
{ #region List转化为Json
/// <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)
{
StringBuilder Json = new StringBuilder();
if (string.IsNullOrEmpty(jsonName))
jsonName = list[].GetType().Name;
Json.Append("{\"" + jsonName + "\":[");
if (list.Count > )
{
for (int i = ; i < list.Count; i++)
{
T obj = Activator.CreateInstance<T>();
PropertyInfo[] pi = obj.GetType().GetProperties();
Json.Append("{");
for (int j = ; 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 - )
{
Json.Append(",");
}
}
Json.Append("}");
if (i < list.Count - )
{
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[];
return ListToJson<T>(list, obj.GetType().Name);
}
#endregion #region 对象转化为Json
/// <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)
{
string jsonString = "{";
PropertyInfo[] propertyInfo = jsonObject.GetType().GetProperties();
for (int i = ; i < propertyInfo.Length; i++)
{
object objectValue = propertyInfo[i].GetGetMethod().Invoke(jsonObject, null);
string value = string.Empty;
if (objectValue is DateTime || objectValue is Guid || objectValue is TimeSpan)
{
value = "'" + objectValue.ToString() + "'";
}
else if (objectValue is string)
{
value = "'" + ToJson(objectValue.ToString()) + "'";
}
else if (objectValue is IEnumerable)
{
value = ToJson((IEnumerable)objectValue);
}
else
{
value = ToJson(objectValue.ToString());
}
jsonString += "\"" + ToJson(propertyInfo[i].Name) + "\":" + value + ",";
}
jsonString.Remove(jsonString.Length - , jsonString.Length);
return jsonString + "}";
}
#endregion #region 对象集合转化为Json
/// <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 - , 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 - , jsonString.Length);
return jsonString + "]";
}
#endregion #region DataTable转化为Json
/// <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(); if (dt.Rows.Count == )
{
jsonString.Append("[{}]");
return jsonString.ToString();
} jsonString.Append("[");
DataRowCollection drc = dt.Rows;
for (int i = ; i < drc.Count; i++)
{
jsonString.Append("{");
for (int j = ; j < dt.Columns.Count; j++)
{
string strKey = dt.Columns[j].ColumnName;
string strValue = drc[i][j].ToString();
Type type = dt.Columns[j].DataType;
jsonString.Append("\"" + strKey + "\":");
strValue = StringFormat(strValue, type);
if (j < dt.Columns.Count - )
{
jsonString.Append(strValue + ",");
}
else
{
jsonString.Append(strValue);
}
}
jsonString.Append("},");
}
jsonString.Remove(jsonString.Length - , );
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 > )
{
for (int i = ; i < dt.Rows.Count; i++)
{
Json.Append("{");
for (int j = ; 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 - )
{
Json.Append(",");
}
}
Json.Append("}");
if (i < dt.Rows.Count - )
{
Json.Append(",");
}
}
}
Json.Append("]}");
return Json.ToString();
}
#endregion #region DataReader转换为Json
/// <summary>
/// DataReader转换为Json
/// </summary>
/// <param name="dataReader">DataReader对象</param>
/// <returns>Json字符串</returns>
public static string ToJson(DbDataReader dataReader)
{
StringBuilder jsonString = new StringBuilder();
jsonString.Append("[");
while (dataReader.Read())
{
jsonString.Append("{");
for (int i = ; i < dataReader.FieldCount; i++)
{
Type type = dataReader.GetFieldType(i);
string strKey = dataReader.GetName(i);
string strValue = dataReader[i].ToString();
jsonString.Append("\"" + strKey + "\":");
strValue = StringFormat(strValue, type);
if (i < dataReader.FieldCount - )
{
jsonString.Append(strValue + ",");
}
else
{
jsonString.Append(strValue);
}
}
jsonString.Append("},");
}
dataReader.Close();
jsonString.Remove(jsonString.Length - , );
jsonString.Append("]");
return jsonString.ToString();
}
#endregion #region DataSet转换为Json
/// <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 + "}";
}
#endregion #region 过滤特殊字符
/// <summary>
/// 过滤特殊字符
/// </summary>
/// <param name="s"></param>
/// <returns></returns>
private static string String2Json(String s)
{
System.Text.StringBuilder sb = new StringBuilder();
for (int i = ; 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();
}
#endregion #region 格式化字符型、日期型、布尔型
/// <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))
{
str = String2Json(str);
str = "\"" + str + "\"";
}
else if (type == typeof(DateTime))
{
str = "\"" + Convert.ToDateTime(str).ToShortDateString() + "\"";
}
else if (type == typeof(bool))
{
str = str.ToLower();
} if (str.Length == )
str = "\"\""; return str;
}
#endregion #region XML转化为Json
/// <summary>
/// XML转化为Json
/// </summary>
/// <param name="Xml">XML 字符串</param>
/// <returns></returns>
public static string XML_Json(string Xml)
{
// To convert an XML node contained in string xml into a JSON string
XmlDocument Xmldoc = new XmlDocument();
Xmldoc.LoadXml(Xml);
string jsonText = JsonConvert.SerializeXmlNode(Xmldoc);
return jsonText;
}
#endregion /// <summary>
/// 生成Json格式
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="obj"></param>
/// <returns></returns>
public static string GetJson<T>(T obj)
{
DataContractJsonSerializer json = new DataContractJsonSerializer(obj.GetType());
using (MemoryStream stream = new MemoryStream())
{
json.WriteObject(stream, obj);
string szJson = Encoding.UTF8.GetString(stream.ToArray()); return szJson;
}
}
/// <summary>
/// 获取Json的Model
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="szJson"></param>
/// <returns></returns>
public static T ParseFromJson<T>(string szJson)
{
T obj = Activator.CreateInstance<T>();
using (MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(szJson)))
{
DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
return (T)serializer.ReadObject(ms);
}
} }
下班了，不多写了，写的很匆忙。两个JsonHelper，建议大家用上边的，因为所以科学道理，你不用，我也没法~！
@陈卧龙的博客