Call Server Side function from JavaScript on JavaScript Confirm Box Yes Button Click in ASP.Net

Hi srihitha,

Check this example. Now please take its reference and correct your code.

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

<asp:ScriptManager runat="server" EnablePageMethods="true" />
<asp:GridView runat="server" ID="GridView1" AutoGenerateColumns="false">
    <Columns>
        <asp:TemplateField HeaderText="Select">
            <ItemTemplate>
                <asp:LinkButton ID="btnDelete" Text="Delete" CommandArgument='<%#Eval("CustomerId")%>'
                    CommandName="rowDelete" runat="server" OnClientClick="if(!SubUnitDeleteErrorWarning_SelectedItem(this)) return false;" />
            </ItemTemplate>
        </asp:TemplateField>
        <asp:BoundField DataField="CustomerId" HeaderText="Id" />
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:BoundField DataField="Country" HeaderText="Country" />
    </Columns>
</asp:GridView>
<script type="text/javascript">
    function SubUnitDeleteErrorWarning_SelectedItem(lnk) {
        var row = lnk.parentNode.parentNode;
        var rowIndex = row.rowIndex - 1;
        var country = row.cells[3].innerHTML;
        PageMethods.GetSubUnitDeleteWarningByID(country, onSuccess, onError);
        function onSuccess(result) {
            if (result > 0) {
                if (confirm("Do you want to delete this subunit so " + result + " travelers will be affected do you want to continue still?")) {
                    PageMethods.DeleteSubUnitByID(country, function () {
                        alert(result + " Travelers deleted.");
                        window.location.reload();
                    }, onError);
                }
            }
            else {
                alert("No Travelers will be affected if you delete this subunit.")
                return false;
            }
        }
        function onError(err) {
            alert(err);
        }
    }
</script>

Namespaces

C#

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

VB.Net

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

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        GridView1.DataSource = GetData();
        GridView1.DataBind();
    }
}

private static DataTable GetData()
{
    string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    string query = "SELECT * FROM Customers";
    SqlCommand cmd = new SqlCommand(query);
    using (SqlConnection con = new SqlConnection(conString))
    {
        using (SqlDataAdapter sda = new SqlDataAdapter())
        {
            cmd.Connection = con;
            sda.SelectCommand = cmd;
            using (DataTable dt = new DataTable())
            {
                sda.Fill(dt);
                return dt;
            }
        }
    }
}

[WebMethod]
public static string GetSubUnitDeleteWarningByID(string country)
{
    return GetData().Select("Country='" + country + "'").Length.ToString();
}

[WebMethod]
public static string DeleteSubUnitByID(string country)
{
    string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    string query = "DELETE FROM Customers WHERE Country = @Country";
    SqlConnection con = new SqlConnection(conString);
    SqlCommand cmd = new SqlCommand(query, con);
    cmd.Parameters.AddWithValue("@Country", country);
    con.Open();
    int count = cmd.ExecuteNonQuery();
    con.Close();
    return count > 0 ? "1" : "0";
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        GridView1.DataSource = GetData()
        GridView1.DataBind()
    End If
End Sub

Private Shared Function GetData() As DataTable
    Dim conString As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Dim query As String = "SELECT * FROM Customers"
    Dim cmd As SqlCommand = New SqlCommand(query)
    Using con As SqlConnection = New SqlConnection(conString)
        Using sda As SqlDataAdapter = New SqlDataAdapter()
            cmd.Connection = con
            sda.SelectCommand = cmd
            Using dt As DataTable = New DataTable()
                sda.Fill(dt)
                Return dt
            End Using
        End Using
    End Using
End Function

<WebMethod()>
Public Shared Function GetSubUnitDeleteWarningByID(ByVal country As String) As String
    Return GetData().Select("Country='" & country & "'").Length.ToString()
End Function

<WebMethod()>
Public Shared Function DeleteSubUnitByID(ByVal country As String) As String
    Dim conString As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Dim query As String = "DELETE FROM Customers WHERE Country = @Country"
    Dim con As SqlConnection = New SqlConnection(conString)
    Dim cmd As SqlCommand = New SqlCommand(query, con)
    cmd.Parameters.AddWithValue("@Country", country)
    con.Open()
    Dim count As Integer = cmd.ExecuteNonQuery()
    con.Close()
    Return If(count > 0, "1", "0")
End Function

Screenshot