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本文主要介绍了如何把DataTable转为JSON
string、如何序列化？如何从txt文件中读取JSON格式的数据并反序列化？总结以及如何移植到web和其他序列化途径等相关。
本文来自于csdn，由火龙果Anna编辑推荐 |
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1.贴出主文件的所有代码
该案例我是用WinForm做的，相信大部分人都是在Web开发中用，这个没关系。
首先你需要给你的Project引入所需的dll。System.Web和System.Web.Extensions如图
好的，下面是我用程序创建的一个JSON 格式的名为”json.txt”的文本。
[{"name":"Jason","id":
"20130001","phone":"13579246810"},
{"name":"Alias","id":
"20130002","phone":"18437965529"},
{"name":"Tom","id":
"20130003","phone":"15090246296"}] |
下面是我的WinForm的UI和识别代码逻辑效果
如何你解析的JSON不是多个对象，而是一个，如：
{"name":"Jason","id":"20130001",
"phone":"13579246810"}
|
那么执行效果如图：
好的，作为辅助，我创建了一个class Person，代码如下：
public class
Person
{
private string _name;
private int _id;
private string _phone;
public string Phone
{
get { return _phone; }
set { _phone = value; }
}
public int Id
{
get { return _id; }
set { _id = value; }
}
public string Name
{
get { return _name; }
set { _name = value; }
}
public Person() { }
public Person(int id, string name, string phone)
{
this._id = id;
this._name = name;
this._phone = phone;
}
} |
然后就是主逻辑代码：如下，
/*
* Author : 刘壮
* Edit Date : 2016/5/1
* Email :
* Description: 1.Create a txt file with json
string.
* 2.Deserialize JSON string by two ways.
* 3.You can type a json with object or a json
array.
*/
using System;
using System.Windows.Forms;
using System.IO;
using System.Web;
using System.Web.Script.Serialization;
using System.Collections.Generic;
using System.Text;
using System.Reflection;
using System.Data;
using System.Collections;
namespace _02_反序列化和反序列化
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private string filename = "json.txt";
JavaScriptSerializer jss = new JavaScriptSerializer();
/// <summary>
/// 创建一个带有json格式的txt
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnCreateJson_Click(object sender,
EventArgs e)
{
//Create a new document with json string.
//Judge whether the specified file exists.
if (!File.Exists(filename))
{
//MessageBox.Show("no existence");
//File.Create(filename);
//Write a json string into the specified file
using (StreamWriter sw = new StreamWriter(filename,
false, System.Text.Encoding.UTF8))
{
//下面通过一个例子演示了如何从json转为DataTable，再由DataTable转为JSON
string.
string json = string.Empty;
json = "[{\"name\":\"Jason\",
\"id\":20130001, \"phone\":\"13579246810\"},"
+
"{\"name\":\"Alias\",
\"id\":20130002, \"phone\":\"18437965529\"},"
+
"{\"name\":\"Tom\",
\"id\":20130003, \"phone\":\"15090246296\"}]";
DataTable dt = new DataTable();
//json = ToJson (new Person(20130001,"Json","12345678901"));
dt = JsonToDataTable(json);
json = DataTableToJson(dt);
sw.Write(json);
}
MessageBox.Show ("the specified have been
created!");
}
else
{
MessageBox.Show ("the file was existing.you
can delete it then re click it.");
}
}
/// <summary>
/// Reading the specified file that contains
a json string
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnAnalyzeJson_Click(object sender,
EventArgs e)
{
//Judge whether the specified file exists.
if (File.Exists(filename))
{
//Getting the string that is a specified file
using (StreamReader sr = new StreamReader(filename,
System.Text.Encoding.UTF8))
{
string json = sr.ReadToEnd();
//analyze the json string.
txtOrgJson.Text = json;
//The first method.(For one object)
//Person p = jss.Deserialize(json,typeof(Person))
as Person;
//txtAnalysedJson.Text = "name="+p.Name+"\r\nid="+
p.Id+"\r\nphone="+p.Phone;
//The second method.(For a lots objects)
List<Person> people = jss.Deserialize<List<Person>>(json);
StringBuilder sb = new StringBuilder();
PropertyInfo[] piArr = typeof(Person).GetProperties(BindingFlags.Instance
| BindingFlags.NonPublic | BindingFlags.Public);
if (people.Count == 0)
{
DeserializeToObject(json);
return;
}
//Get the name and value of the specified
class Person automatically.
foreach (var person in people)
{
sb.Clear();
foreach (PropertyInfo pi in piArr)
{
sb.Append(pi.Name + "=" + pi.GetValue(person));
sb.Append("\t ");
}
listAll.Items.Add(sb.ToString());
//listAll.Items.Add("name=" + person.Name
+ "\tid=" + person.Id + "\tphone="
+ person.Phone);
}
}
}
else
{
MessageBox.Show ("Cannot find the specified
file.Please click the up button of this.");
}
}
/// <summary>
/// Converts the specified JSON string to a
object of type T.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="jsonString"></param>
/// <returns></returns>
private T Deserialize<T>(string jsonString)
{
JavaScriptSerializer json = new JavaScriptSerializer();
return json.Deserialize<T>(jsonString);
}
private void btnDelFile_Click (object sender,
EventArgs e)
{
if (File.Exists(filename))
{
File.Delete(filename);
MessageBox.Show("Deleted");
}
}
/// <summary>
/// Convert JSON string to Object
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnConvert_Click (object sender,
EventArgs e)
{
string json = txtOrgJson.Text.Trim();
if (!String.IsNullOrEmpty(json))
{
List<Person> lPerson = Deserialize <List<Person>>(json);
StringBuilder sb = new StringBuilder();
PropertyInfo[] piArr = typeof(Person).GetProperties
(BindingFlags.Instance | BindingFlags.NonPublic
| BindingFlags.Public);
if (lPerson.Count == 0)
{
DeserializeToObject(json);
return;
}
//Get the name and value of the specified
class Person automatically.
foreach (var person in lPerson)
{
sb.Clear();
foreach (PropertyInfo pi in piArr)
{
sb.Append(pi.Name + "=" + pi.GetValue(person));
sb.Append("\t ");
}
listAll.Items.Add(sb.ToString());
}
}
}
/// <summary>
/// Clear the listbox
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnClear_Click (object sender,
EventArgs e)
{
listAll.Items.Clear();
}
private void DeserializeToObject (string data)
{
Person p = jss.Deserialize (data, typeof(Person))
as Person;
txtAnalysedJson.Text = "name= " + p.Name
+ "\r\nid=" + p.Id + "\r\nphone="
+ p.Phone;
}
/// <summary>
/// ConvertS an object to a JSON string
/// </summary>
/// <param name="o">Object</param>
/// <returns></returns>
private string ToJson(Object o)
{
JavaScriptSerializer j = new JavaScriptSerializer();
return j.Serialize(o);
}
/// <summary>
/// ConvertS an object to a JSON string When
the string length is long
/// </summary>
/// <param name="o"></param>
/// <returns></returns>
private string ToJson2(Object o)
{
JavaScriptSerializer j = new JavaScriptSerializer();
j.MaxJsonLength = Int32.MaxValue;
return j.Serialize(o);
}
/// <summary>
/// Converts datatable to JSON string.
/// </summary>
/// <param name="dt"></param>
/// <returns></returns>
private string DataTableToJson(DataTable dt)
{
JavaScriptSerializer javaScriptSerializer =
new JavaScriptSerializer();
javaScriptSerializer.MaxJsonLength = Int32.MaxValue;
//取得最大数值
ArrayList arrayList = new ArrayList();
foreach (DataRow dataRow in dt.Rows)
{
Dictionary<string, object> dictionary
= new Dictionary<string, object>(); //实例化一个参数集合
foreach (DataColumn dataColumn in dt.Columns)
{
dictionary.Add (dataColumn.ColumnName, dataRow
[dataColumn.ColumnName].ToString());
}
arrayList.Add(dictionary); //ArrayList集合中添加键值
}
return javaScriptSerializer.Serialize(arrayList);
//返回一个json字符串
}
/// <summary>
/// Json 字符串 转换为 DataTable数据集合
/// </summary>
/// <param name="json"></param>
/// <returns></returns>
public DataTable JsonToDataTable (string json)
{
DataTable dataTable = new DataTable(); //实例化
DataTable result;
try
{
JavaScriptSerializer javaScriptSerializer =
new JavaScriptSerializer();
javaScriptSerializer.MaxJsonLength = Int32.MaxValue;
//取得最大数值
ArrayList arrayList = javaScriptSerializer.Deserialize<ArrayList>(json);
if (arrayList.Count > 0)
{
foreach (Dictionary<string, object> dictionary
in arrayList)
{
if (dictionary.Keys.Count == 0)
{
result = dataTable;
return result;
}
if (dataTable.Columns.Count == 0)
{
foreach (string current in dictionary.Keys)
{
dataTable.Columns.Add (current, dictionary[current].GetType());
}
}
DataRow dataRow = dataTable.NewRow();
foreach (string current in dictionary.Keys)
{
dataRow[current] = dictionary[current];
}
dataTable.Rows.Add(dataRow); //循环添加行到DataTable中
}
}
}
catch
{
}
result = dataTable;
return result;
}
}
} |
上面用到了很多方法，都是很重要很重要很重要的，重要是事情要说三遍！！！由于使用的WinForm开发的，所以上面的代码中会含有部分控件的Name。
下面我将会分开部分讲一下该案例的核心方法
2.逐个分析之如何把JSON string 转为DataTable
1.首先创建一个JsonToDataTable的通用方法
/// <summary>
/// Json 字符串 转换为 DataTable数据集合
/// </summary>
/// <param name="json"></param>
/// <returns></returns>
public DataTable JsonToDataTable(string json)
{
DataTable dataTable = new DataTable(); //实例化
DataTable result;
try
{
JavaScriptSerializer javaScriptSerializer =
new JavaScriptSerializer();
javaScriptSerializer.MaxJsonLength = Int32.MaxValue;
//取得最大数值
ArrayList arrayList = javaScriptSerializer.Deserialize<ArrayList>(json);
if (arrayList.Count > 0)
{
foreach (Dictionary<string, object> dictionary
in arrayList)
{
if (dictionary.Keys.Count == 0)
{
result = dataTable;
return result;
}
if (dataTable.Columns.Count == 0)
{
foreach (string current in dictionary.Keys)
{
dataTable.Columns.Add(current, dictionary[current].GetType());
}
}
DataRow dataRow = dataTable.NewRow();
foreach (string current in dictionary.Keys)
{
dataRow[current] = dictionary[current];
}
dataTable.Rows.Add(dataRow); //循环添加行到DataTable中
}
}
}
catch
{
}
result = dataTable;
return result;
} |
2.新建一个json字符串并赋值。然后调用上面的方法就可以转为DataTable了。
string json
= string.Empty;
json = "[{\"name\":\"Jason\",\"id\":20130001,
\"phone\":\"13579246810\"},"
+
"{\"name\":\"Alias\",
\"id\":20130002, \"phone\":\"18437965529\"},"
+
"{\"name\":\"Tom\",\"id\":
20130003,\"phone\":\"15090246296\"}]";
DataTable dt = JsonToDataTable(json);
|
3.如何把DataTable转为JSON string
1.新建一个DataTableToJson的方法
/// <summary>
/// Converts datatable to JSON string.
/// </summary>
/// <param name="dt"></param>
/// <returns></returns>
private string DataTableToJson(DataTable dt)
{
JavaScriptSerializer javaScriptSerializer =
new JavaScriptSerializer();
javaScriptSerializer.MaxJsonLength = Int32.MaxValue;
//取得最大数值
ArrayList arrayList = new ArrayList();
foreach (DataRow dataRow in dt.Rows)
{
Dictionary<string, object> dictionary
= new Dictionary<string, object>(); //实例化一个参数集合
foreach (DataColumn dataColumn in dt.Columns)
{
dictionary.Add (dataColumn.ColumnName, dataRow[dataColumn.ColumnName].ToString());
}
arrayList.Add(dictionary); //ArrayList集合中添加键值
}
return javaScriptSerializer.Serialize(arrayList);
//返回一个json字符串
} |
2.调用方法，传入一个DataTable就可以。哪个DataTable都可以的。
string json
= DataTableToJson(dt);
|
4.如何序列化？
1.创建一个方法
/// <summary>
/// ConvertS an object to a JSON string When
the string length is long
/// </summary>
/// <param name="o"></param>
/// <returns></returns>
private string ToJson2(Object o)
{
JavaScriptSerializer j = new JavaScriptSerializer();
j.MaxJsonLength = Int32.MaxValue;
return j.Serialize(o);
} |
2.就这样传入一个对象就行了。
比如：Person p = new Person();string json = ToJson2(p);
上面在DataTable中也用到过序列化的Demo，可以参考用到大量数据时进行转JSON
5.如何从txt文件中读取JSON格式的数据并反序列化
简述下流程：
1.判断txt的存在
2.读取txt的内容
3.通过下面的代码把JSON对象存入一个泛型中
List<Person>
people = jss.Deserialize<List<Person>>(json); |
4.通过映射，自动获取到JSON对应类(Class)的属性名，实现自动化并通过遍历输出
|
PropertyInfo[]
piArr = typeof(Person).GetProperties (BindingFlags.Instance
| BindingFlags.NonPublic | BindingFlags.Public);
if (people.Count == 0)
{
DeserializeToObject(json);
return;
}
//Get the name and value of the specified
class Person automatically.
foreach (var person in people)
{
sb.Clear();
foreach (PropertyInfo pi in piArr)
{
sb.Append(pi.Name + "=" + pi.GetValue(person));
sb.Append("\t ");
}
listAll.Items.Add(sb.ToString());
//listAll.Items.Add ("name=" + person.Name
+ "\tid=" + person.Id + "\tphone="
+ person.Phone);
} |
下面是用到的方法
| /// <summary>
/// Reading the specified file that contains
a json string
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnAnalyzeJson_Click(object sender,
EventArgs e)
{
//Judge whether the specified file exists.
if (File.Exists(filename))
{
//Getting the string that is a specified file
using (StreamReader sr = new StreamReader(filename,
System.Text.Encoding.UTF8))
{
string json = sr.ReadToEnd();
//analyze the json string.
txtOrgJson.Text = json;
//The first method.(For one object)
//Person p = jss.Deserialize (json,typeof(Person))
as Person;
//txtAnalysedJson.Text = "name= "+p.Name+"\r\nid="+p.Id+"\r\nphone="+p.Phone;
//The second method.( For a lots objects)
List<Person> people = jss.Deserialize<List<Person>>(json);
StringBuilder sb = new StringBuilder();
PropertyInfo[] piArr = typeof(Person).GetProperties(BindingFlags.Instance
| BindingFlags.NonPublic | BindingFlags.Public);
if (people.Count == 0)
{
DeserializeToObject(json);
return;
}
//Get the name and value of the specified
class Person automatically.
foreach (var person in people)
{
sb.Clear();
foreach (PropertyInfo pi in piArr)
{
sb.Append(pi.Name + "=" + pi.GetValue(person));
sb.Append("\t ");
}
listAll.Items.Add(sb.ToString());
//listAll.Items.Add("name=" + person.Name
+ "\tid=" + person.Id + "\tphone="
+ person.Phone);
}
}
}
else
{
MessageBox.Show("Cannot find the specified
file.Please click the up button of this.");
}
} |
6.总结以及如何移植到web和其他序列化途径
先写这么多，你有什么疑问也可以留言交流一下，该案例仅供参考，不代表标准案例。另外，由于这里用的是WinForm开发，你在Web里通过POST方法传入json数据时，可能需要通过下面的方法获取到json
string
StreamReader reader
= new StreamReader (context.Request.InputStream);
//比如得到json字符串：strJson={"key3":"xdp-gacl","key4":"白皇"}
String strJson = HttpUtility.UrlDecode (reader.ReadToEnd());
|
然后下面就是按上面的案例中的方法进行优化，调整。
另外呢，如果是传入的JSON string是一个，那么可以通过键值对的方式来读取：
/// <summary>
/// 获取参数
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
private System.Collections.Generic.Dictionary<String,
Object> GetParameter(HttpContext context)
{
StreamReader reader = new StreamReader(context.Request.InputStream);
//得到json字符串：strJson= {"key3":"xdp-gacl","key4":"白虎神皇"}
String strJson = HttpUtility.UrlDecode (reader.ReadToEnd());
System.Web.Script.Serialization .JavaScriptSerializer
jss = new System.Web.Script.Serialization .JavaScriptSerializer();
//将json字符串反序列化成一个Dictionary对象
System.Collections.Generic .Dictionary<String,
Object> dicParameter = jss.Deserialize<
System.Collections.Generic.Dictionary <String,
Object>>(strJson);
return dicParameter;
} |
调用方式
Dictionary<String,
Object> dicParameter = GetParameter(context);
string key3 = dicParameter["keyword"].ToString(); |
另外呢，除了上面的序列化之外，还可以用下面的方法：
public static string
ToJsJson(object item)
{
DataContractJsonSerializer serializer = new
DataContractJsonSerializer(item.GetType());
using (MemoryStream ms = new MemoryStream())
{
serializer.WriteObject(ms, item);
StringBuilder sb = new StringBuilder("");
sb.Append(Encoding.UTF8.GetString(ms.ToArray()));
return sb.ToString();
}
} |
需要你引用：using System.Runtime.Serialization.Json; |
