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C#操作json类型数据

2018-06-18 02:59:08来源：未知阅读 ()

将对象序列化为 JavaScript 对象表示法 (JSON)，并将 JSON 数据反序列化为对象。此类不能继承。

//　　msdn 例子:

[csharp] view plaincopy

namespace SL_DataContractJsonSerializer
{
public partial class Page : UserControl
{
public Page()
{
InitializeComponent();
}
//This uses an event handler, not SL data binding
void OnClick(object sender, EventArgs args)
{
txtOutput1.Text = "Create a User object and serialize it.";
string json = WriteFromObject();
txtOutput2.Text = json.ToString(); // Displays: {"Age":42,"Name":"Bob"}
txtOutput3.Text = "Deserialize the data to a User object.";
string jsonString = "{'Name':'Bill', 'Age':53}";
User deserializedUser = ReadToObject(jsonString);
txtOutput4.Text = deserializedUser.Name; // Displays: Bill
txtOutput5.Text = deserializedUser.Age.ToString(); // Displays: 53
}
// Create a User object and serialize it to a JSON stream.
public static string WriteFromObject()
{
//Create User object.
User user = new User("Bob", 42);
//Create a stream to serialize the object to.
MemoryStream ms = new MemoryStream();
// Serializer the User object to the stream.
DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(User));
ser.WriteObject(ms, user);
byte[] json = ms.ToArray();
ms.Close();
return Encoding.UTF8.GetString(json, 0, json.Length);
}
// Deserialize a JSON stream to a User object.
public static User ReadToObject(string json)
{
User deserializedUser = new User();
MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(json));
DataContractJsonSerializer ser = new DataContractJsonSerializer(deserializedUser.GetType());
deserializedUser = ser.ReadObject(ms) as User;
ms.Close();
return deserializedUser;
}
}
[DataContract]
public class User
{
[DataMember]
public string Name { get; set; }
[DataMember]
public int Age { get; set; }
public User() { }
public User(string newName, int newAge)
{
Name = newName;
Age = newAge;
}
}
}

可以抽象成如下类:

[csharp] view plaincopy

public class JsonHelper
{
/// <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);
}
}
}

[csharp] view plaincopy

/// <summary>
/// 反回JSON数据到前台
/// </summary>
/// <param name="dt">数据表</param>
/// <returns>JSON字符串</returns>
public string DataTableToJson(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;
}
}