.net 中Json序列化和反序列化的类

现在经常会用到json,因此经常会需要对其进行序列化和反序列化。，.NET Framewok 3.5也提供了JSON对象序列化和反序列化的类，这就是System.Runtime.Serialization.Json 命名空间下的 DataContractJsonSerializer 类。利用这个类，可以实现JSON对象的序列化和反序列化。

现在我提供一个类JSON对象序列化和反序列化的类供参考用：

/// <summary>
/// JSON帮助类。用于将对象转换为Json格式的字符串，或者将Json的字符串转化为对象。
/// </summary>
public static class JsonHelper
{
/// <summary>
/// 将对象转化为Json字符串
/// </summary>
/// <typeparam name="T">源类型</typeparam>
/// <param name="obj">源类型实例</param>
/// <returns>Json字符串</returns>
public static string GetJsonFromObj<T>(T obj)
{
DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(obj.GetType());
using (MemoryStream ms = new MemoryStream())
{
jsonSerializer.WriteObject(ms, obj);
return Encoding.UTF8.GetString(ms.ToArray());
}
}

/// <summary>
/// 将Json字符串转化为对象
/// </summary>
/// <typeparam name="T">目标类型</typeparam>
/// <param name="strJson">Json字符串</param>
/// <returns>目标类型的一个实例</returns>
public static T GetObjFromJson<T>(string strJson)
{
T obj = Activator.CreateInstance<T>();
using (MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(strJson)))
{
DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(obj.GetType());
return (T)jsonSerializer.ReadObject(ms);
}
}

/// <summary>
/// 将DataTable转换为JSON字符串
/// </summary>
/// <param name="dt">数据表</param>
/// <returns>JSON字符串</returns>
public static string GetJsonFromDataTable(DataTable dt)
{
StringBuilder JsonString = new StringBuilder();
if (dt != null && dt.Rows.Count > 0)
{
JsonString.Append("{ ");
JsonString.Append("\"TableInfo\":[ ");
for (int i = 0; i < dt.Rows.Count; i++)
{
JsonString.Append("{ ");
for (int j = 0; j < dt.Columns.Count; j++)
{
if (j < dt.Columns.Count - 1)
{
JsonString.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":" + "\"" + dt.Rows[i][j].ToString() + "\",");
}
else if (j == dt.Columns.Count - 1)
{
JsonString.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":" + "\"" + dt.Rows[i][j].ToString() + "\"");
}
}
if (i == dt.Rows.Count - 1)
{
JsonString.Append("} ");
}
else
{
JsonString.Append("}, ");
}
}
JsonString.Append("]}");
return JsonString.ToString();
}
else
{
return null;
}
}

/// <summary>
/// 将对象转化为Json字符串
/// </summary>
/// <param name="obj">源对象</param>
/// <returns>json数据</returns>
public static string ObjToJson(this object obj)
{
JavaScriptSerializer serialize = new JavaScriptSerializer();
return serialize.Serialize(obj);
}

/// <summary>
/// 将Json字符串转化为对象
/// </summary>
/// <param name="strJson">Json字符串</param>
/// <returns>目标对象</returns>
public static T JsonToObj<T>(string strJson)
{
JavaScriptSerializer serialize = new JavaScriptSerializer();
return serialize.Deserialize<T>(strJson);
}

/// <summary>
/// 将对象转化为Json字符串(控制深度 )
/// </summary>
/// <param name="obj">源对象</param>
/// <param name="recursionDepth">深度</param>
/// <returns>json数据</returns>
public static string ObjToJson(this object obj, int recursionDepth)
{
JavaScriptSerializer serialize = new JavaScriptSerializer();
serialize.RecursionLimit = recursionDepth;
return serialize.Serialize(obj);
}

/// <summary>
/// 将Json字符串转化为对象(控制深度 )
/// </summary>
/// <param name="strJson">Json字符串</param>
/// <param name="recursionDepth">深度</param>
/// <returns>目标对象</returns>
public static T JsonToObj<T>(string strJson, int recursionDepth)
{
JavaScriptSerializer serialize = new JavaScriptSerializer();
serialize.RecursionLimit = recursionDepth;
return serialize.Deserialize<T>(strJson);
}

/// <summary>
/// 将DataTable转换为JSON字符串
/// </summary>
/// <param name="dt">DataTable</param>
/// <returns>json数据</returns>
public static string DataTableToJson(DataTable dt)
{
Dictionary<string, object> dic = new Dictionary<string, object>();

int index = 0;
foreach (DataRow dr in dt.Rows)
{
Dictionary<string, object> result = new Dictionary<string, object>();

foreach (DataColumn dc in dt.Columns)
{
result.Add(dc.ColumnName, dr[dc].ToString());
}
dic.Add(index.ToString(), result);
index++;
}
return ObjToJson(dic);
}
}

调用代码如下：

public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

}

protected void Button1_Click(object sender, EventArgs e)
{
//反序列化成对象
String strJson = "{\"Name\":\"Test123\",\"Url\":\"http://www.126.com/\"}";
Person p1 = JsonHelper.GetObjFromJson<Person>(strJson);
Response.Write("<li>" + p1.Name + " " + p1.Url);
Person p2 = JsonHelper.JsonToObj<Person>(strJson);
Response.Write("<li>" + p2.Name + " " + p2.Url);
}

protected void Button2_Click(object sender, EventArgs e)
{
//对象的序列化
String JSONString = string.Empty;
Person p1 = new Person();
p1.Name = "Test123'\"\n\r\t";
p1.Url = "http://www.126.com/";
JSONString = JsonHelper.GetJsonFromObj<Person>(p1);
Response.Write("<li>" + JSONString);
JSONString = JsonHelper.ObjToJson(p1);
Response.Write("<li>" + JSONString);
}
}

/// <summary>
/// 类对象需要标记为DataContractAttribute
/// </summary>
[DataContractAttribute]
class Person
{
//成员需要标记为 DataMember
[DataMember]
public string Name { set; get; }
[DataMember]
public string Url { set; get; }
}