前后台传值一般情况下，都会用到json类型的数据，比较常见，但是每次用到的时候去网上找比较麻烦，所以自己记录一下，下次直接用。

构造的json串格式，如下：

[{
   "id":"0","name":"name","active":"active","user_id":"user_id","no_of_reports":"no_of_reports"}, {
   "id":"1","name":"name","active":"active","user_id":"user_id","no_of_reports":"no_of_reports"}, {
   "id":"2","name":"name","active":"active","user_id":"user_id","no_of_reports":"no_of_reports"}, {
   "id":"3","name":"name","active":"active","user_id":"user_id","no_of_reports":"no_of_reports"}, {
   "id":"4","name":"name","active":"active","user_id":"user_id","no_of_reports":"no_of_reports"}, {
   "id":"5","name":"name","active":"active","user_id":"user_id","no_of_reports":"no_of_reports"}, {
   "id":"6","name":"name","active":"active","user_id":"user_id","no_of_reports":"no_of_reports"}, {
   "id":"7","name":"name","active":"active","user_id":"user_id","no_of_reports":"no_of_reports"}, {
   "id":"8","name":"name","active":"active","user_id":"user_id","no_of_reports":"no_of_reports"}, {
   "id":"9","name":"name","active":"active","user_id":"user_id","no_of_reports":"no_of_reports"}]

一、构造DataTable

public DataTable getData()        {            DataTable dt = new DataTable();            dt.Columns.Add("id", typeof(Int32));            dt.Columns.Add("name", typeof(string));            dt.Columns.Add("active", typeof(string));            dt.Columns.Add("user_id", typeof(string));            dt.Columns.Add("no_of_reports", typeof(string));            for (int i = 0; i < 10; i++)            {                dt.Rows.Add(i, "name", "active", "user_id", "no_of_reports");            }            return dt;        }

二、DataTable转json

public string DataTableToJsonWithStringBuilder(DataTable table)        {            var jsonString = new StringBuilder();            if (table.Rows.Count > 0)            {                jsonString.Append("[");                for (int i = 0; i < table.Rows.Count; i++)                {                    jsonString.Append("{
    ");                    for (int j = 0; j < table.Columns.Count; j++)                    {                        if (j < table.Columns.Count - 1)                        {                            jsonString.Append("\"" + table.Columns[j].ColumnName.ToString()                         + "\":" + "\""                         + table.Rows[i][j].ToString() + "\",");                        }                        else if (j == table.Columns.Count - 1)                        {                            jsonString.Append("\"" + table.Columns[j].ColumnName.ToString()                         + "\":" + "\""                         + table.Rows[i][j].ToString() + "\"");                        }                    }                    if (i == table.Rows.Count - 1)                    {                        jsonString.Append("}");                    }                    else                    {                        jsonString.Append("},");                    }                }                jsonString.Append("]");            }            return jsonString.ToString();        }

三、调用

DataTable dt = getData();  string str = DataTableToJsonWithStringBuilder(dt);