Hi Faizal,

Check this example. Now please take its reference and correct your code. Referring the below article i have created the example.

Set TextBox value on Button Click using AngularJS

Database

I have made use of the following table Customers with the schema as follows.

I have already inserted few records in the table.

You can download the database table SQL by clicking the download link below.

Download SQL file

HTML

<div ng-app="MyApp" ng-controller="MyController">
    ID:<input type="text" ng-model="Id">
    <br />
    Name:<input type="text" ng-model="Name">
    <br />
    <input type="button" value="Get Name" ng-click="GetName()" />
</div>
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/angularjs/1.3.9/angular.min.js"></script>
<script type="text/javascript">
    var app = angular.module('MyApp', [])
    app.controller('MyController', function ($scope, $http, $window) {
        $scope.GetName = function () {
            var post = $http({
                method: "POST",
                url: "Default.aspx/GetCustomerName",
                dataType: 'json',
                data: '{id:' + $scope.Id + '}',
                headers: { "Content-Type": "application/json" }
            });
            post.success(function (data, status) {
                $scope.Name = data.d;
            });
            post.error(function (data, status) {
                $window.alert(data.Message);
            });
        }
    });
</script>

Namespaces

C#

using System.Configuration;
using System.Data.SqlClient;
using System.Web.Services;

VB.Net

Imports System.Web.Services
Imports System.Data.SqlClient

Code

C#

[WebMethod]
public static string GetCustomerName(int id)
{
    string name = "";
    string strConnString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(strConnString))
    {
        using (SqlCommand cmd = new SqlCommand())
        {
            cmd.Connection = con;
            con.Open();
            cmd.CommandText = "SELECT Name FROM Customers WHERE CustomerId = @Id";
            cmd.Parameters.AddWithValue("@Id", id);
            name = cmd.ExecuteScalar().ToString();
            con.Close();
        }
    }
 
    return name;
}

VB.Net

<WebMethod()>
Public Shared Function GetCustomerName(ByVal id As Integer) As String
    Dim name As String = ""
    Dim strConnString As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As SqlConnection = New SqlConnection(strConnString)
        Using cmd As SqlCommand = New SqlCommand()
            cmd.Connection = con
            con.Open()
            cmd.CommandText = "SELECT Name FROM Customers WHERE CustomerId = @Id"
            cmd.Parameters.AddWithValue("@Id", id)
            name = cmd.ExecuteScalar().ToString()
            con.Close()
        End Using
    End Using
 
    Return name
End Function

Screenshot