DataTable转换成JSON字符串

    private string DataTable2Json(DataTable dt)
    ...{
         StringBuilder jsonBuilder = new StringBuilder();
         jsonBuilder.Append("{\"");
         jsonBuilder.Append(dt.TableName);
         jsonBuilder.Append("\":[");
        for (int i = 0; i < dt.Rows.Count; i++)
        ...{
             jsonBuilder.Append("{");
            for (int j = 0; j < dt.Columns.Count; j++)
            ...{
                 jsonBuilder.Append("\"");
                 jsonBuilder.Append(dt.Columns[j].ColumnName);
                 jsonBuilder.Append("\":\"");
                 jsonBuilder.Append(dt.Rows[i][j].ToString());
                 jsonBuilder.Append("\",");
             }
             jsonBuilder.Remove(jsonBuilder.Length - 1, 1);
             jsonBuilder.Append("},");
         }
         jsonBuilder.Remove(jsonBuilder.Length - 1, 1);
         jsonBuilder.Append("]");
         jsonBuilder.Append("}");
        return jsonBuilder.ToString();
     }