Display GridView selected row value in Bootstrap modal in ASP.Net

Hi Rajan,

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

HTML

<div class="container">
    <div class="table-responsive">
        <asp:GridView ID="GridView1" AutoGenerateColumns="false" runat="server"
            CssClass="table table-bordered table-hover table-striped thead-dark">
            <Columns>
                <asp:BoundField DataField="Id" HeaderText="ID" />
                <asp:BoundField DataField="Name" HeaderText="Name" />
                <asp:BoundField DataField="Country" HeaderText="Country" />
                <asp:TemplateField>
                    <ItemTemplate>
                        <asp:LinkButton ID="lnkEdit" href="#" data-target="#MyPopup" 
                            data-toggle="modal" runat="server">Edit</asp:LinkButton>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
    </div>
</div>
<div id="MyPopup" class="modal fade" role="dialog">
    <div class="modal-dialog">
        <div class="modal-content">
            <div class="modal-header">
                <button type="button" class="close" data-dismiss="modal">
                    &times;</button>
                <h4 class="modal-title">Update Customer
                </h4>
            </div>
            <div class="modal-body">
                <table class="table table-bordered table-hover table-striped thead-dark">
                    <tr>
                        <td>Id</td>
                        <td><asp:TextBox runat="server" ID="txtId" ReadOnly="true" CssClass="form-control" /></td>
                    </tr>
                    <tr>
                        <td>Name</td>
                        <td><asp:TextBox runat="server" ID="txtName" CssClass="form-control" /></td>
                    </tr>
                    <tr>
                        <td>Country</td>
                        <td><asp:TextBox runat="server" ID="txtCountry" CssClass="form-control" /></td>
                    </tr>
                </table>
            </div>
            <div class="modal-footer">
                <asp:Button ID="btnUpdate" Text="Update" runat="server" CssClass="btn btn-primary" OnClick="OnUpdate" />
                <input type="button" value="Close" class="btn btn-danger" data-dismiss="modal" />
            </div>
        </div>
    </div>
</div>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css" />
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script type="text/javascript" src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/js/bootstrap.min.js"></script>
<script type="text/javascript">
    $(function () {
        $("[id*=lnkEdit]").click(function () {
            $('#txtId').val($(this).closest('tr').find('td').eq(0).html());
            $('#txtName').val($(this).closest('tr').find('td').eq(1).html());
            $('#txtCountry').val($(this).closest('tr').find('td').eq(2).html());
        });
    });
</script>

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        System.Data.DataTable dt = new System.Data.DataTable();
        dt.Columns.AddRange(new System.Data.DataColumn[3]
        {
            new System.Data.DataColumn("Id"),
            new System.Data.DataColumn("Name"),
            new System.Data.DataColumn("Country")
        });
        dt.Rows.Add(1, "John Hammond", "United States");
        dt.Rows.Add(2, "Mudassar Khan", "India");
        dt.Rows.Add(3, "Suzanne Mathews", "France");
        dt.Rows.Add(4, "Robert Schidner", "Russia");
        GridView1.DataSource = dt;
        GridView1.DataBind();
    }
}

protected void OnUpdate(object sender, EventArgs e)
{
    // Code to update the record.
    string id = Request.Form["txtId"];
    string name= Request.Form["txtName"];
    string country = Request.Form["txtCountry"];
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim dt As Data.DataTable = New Data.DataTable()
        dt.Columns.AddRange(New Data.DataColumn(2) {
                            New Data.DataColumn("Id"),
                            New Data.DataColumn("Name"),
                            New Data.DataColumn("Country")})
        dt.Rows.Add(1, "John Hammond", "United States")
        dt.Rows.Add(2, "Mudassar Khan", "India")
        dt.Rows.Add(3, "Suzanne Mathews", "France")
        dt.Rows.Add(4, "Robert Schidner", "Russia")
        GridView1.DataSource = dt
        GridView1.DataBind()
    End If
End Sub

Protected Sub OnUpdate(ByVal sender As Object, ByVal e As EventArgs)
    ' Code to update the record.
    Dim id As String = Request.Form("txtId")
    Dim name As String = Request.Form("txtName")
    Dim country As String = Request.Form("txtCountry")
End Sub

Screenshot