JSON With C#

This blog entices you to learn JSON with C#, using Web Services.

Introduction

JSON (JavaScript Object Notation) is a lightweight data-interchange format. JSON is a syntax to store and exchange the data. JSON is a text, written with JavaScript object notation.

Exchanging data

JSON.stringify()- Send

JSON.parse() - Receive

Data Format

{ "name":"Sakthi", "Designation":"Software Engineer", "Salary":10000 };

ASP page (or) HTML

<form id="form2" runat="server">
    <div>
        <script>
            debugger;
            var obj, parameter, xmlhttp, _Obj, x, result = "";
            obj = {
                "Designation": "Software",
                "salary": 10000
            }; // WHERE CONDITION
            dbParam = JSON.stringify(obj); // SEND PARAMETERS
            xmlhttp = new XMLHttpRequest();
            xmlhttp.onreadystatechange = function() {
                if (this.readyState == 4 && this.status == 200) {
                    _Obj = JSON.parse(this.responseText); // RECEIVE
                    result += "<table border='1'>"
                    for (x in _Obj) {
                        result += "<tr><td>" + _Obj[x].val + "</td></tr>";
                    }
                    result += "</table>"
                    document.getElementById("demo").innerHTML = result;
                }
            };
            xmlhttp.open("POST", "./ReadTable.asmx/getdata", true); //METHOD POST–WEBSERVICE PAGE
            xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
            xmlhttp.send("x=" + parameter);
        </script>
        <p id="demo"></p>
    </div>
</form>

NOTE

Webservice Name ReadTable.asmx

Method Name getdata

ReadTable.cs

[WebMethod]
public void getdata(string x) {
    JavaScriptSerializer j = new JavaScriptSerializer();
    string json = new StreamReader(Context.Request.InputStream).ReadToEnd();
    Dictionary < string, string > sData = j.Deserialize < Dictionary < string, string >> (x);
    string Designation = sData["Designation"].ToString();
    String Salary = sData["Salary"].ToString();
    List < UserList > c = new List < UserList > ();
    SqlConnection con = new SqlConnection("");
    con.Open();
    SqlCommand cmd = new SqlCommand("select * from TableName where Designation=@Designation and Salary=@Salary", con);
    cmd.Parameters.AddWithValue("@Designation", Designation);
    cmd.Parameters.AddWithValue("@Salary", Salary);
    SqlDataAdapter da = new SqlDataAdapter(cmd);
    DataTable dt = new DataTable();
    da.Fill(dt);
    for (int i = 0; i < dt.Rows.Count; i++) {
        UserList _userlist = new UserList();
        _userlist.val = dt.Rows[i][0].ToString();...c.Add(_userList);
    }
    JavaScriptSerializer j2 = new JavaScriptSerializer();
    Context.Response.Write(j2.Serialize(c));
}

USERLIST CLASS FILE

class UserList {
    public string val {
        get;
        set;
    }
    public string val2 {
        get;
        set;
    }
    public string val3 {
        get;
        set;
    }...
}