Dynamically add n number of Rows in ASP.Net GridView based on TextBox using C# and VB.Net

Hi lingers,

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

HTML

<asp:TextBox ID="txtNo" runat="server" />
<asp:Button ID="Button1" Text="Add" OnClick="Add" runat="server" />
<hr />
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
    <Columns>
        <asp:TemplateField HeaderText="First Name">
            <ItemTemplate>
                <asp:TextBox ID="txtFirstName" runat="server" Text='<%# Eval("FirstName") %>' />
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Last Name">
            <ItemTemplate>
                <asp:TextBox ID="txtLastName" runat="server" Text='<%# Eval("LastName") %>' />
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>
<asp:Button Text="Save" runat="server" OnClick="OnSave" />

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (this.GridView1.Rows.Count > 0 && Session["myDatatable"] != null)
    {
        DataTable dt = (DataTable)Session["myDatatable"];
        dt.Clear();
        foreach (GridViewRow row in this.GridView1.Rows)
        {
            string firstName = (row.FindControl("txtFirstName") as TextBox).Text;
            string lastName = (row.FindControl("txtLastName") as TextBox).Text;
            dt.Rows.Add(firstName, lastName);
        }
        GridView1.Visible = true;
        GridView1.DataSource = dt;
        GridView1.DataBind();
        Session["myDatatable"] = dt;
    }
}

public void AddNewData()
{
    DataTable dt = new DataTable();
    if (Session["myDatatable"] != null)
    {
        dt = (DataTable)Session["myDatatable"];
    }
    else
    {
        dt.Columns.Add("FirstName");
        dt.Columns.Add("LastName");
    }

    DataRow drow = dt.NewRow();
    drow["FirstName"] = "";
    drow["LastName"] = "";
    dt.Rows.Add(drow);
    Session["myDatatable"] = dt;
}

public void BindGridview()
{
    if (Session["myDatatable"] != null)
    {
        DataTable dt = (DataTable)Session["myDatatable"];

        if ((dt != null) && (dt.Rows.Count > 0))
        {
            GridView1.Visible = true;
            GridView1.DataSource = dt;
            GridView1.DataBind();
        }
        else
        {
            GridView1.Visible = false;
        }
    }
}

protected void Add(object sender, EventArgs e)
{
    for (int i = 0; i < Convert.ToInt32(txtNo.Text); i++)
    {
        AddNewData();
    }
    BindGridview();
}
protected void OnSave(object sender, EventArgs e)
{
    foreach (GridViewRow row in GridView1.Rows)
    {
        string firstName = (row.FindControl("txtFirstName") as TextBox).Text;
        string lastName = (row.FindControl("txtLastName") as TextBox).Text;
        string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        string query = "INSERT INTO Student VALUES(@First,@Last)";
        using (SqlConnection con = new SqlConnection(conString))
        {
            using (SqlCommand cmd = new SqlCommand(query))
            {
                cmd.Connection = con;
                cmd.Parameters.AddWithValue("@First",firstName);
                cmd.Parameters.AddWithValue("@Last", lastName);
                con.Open();
                cmd.ExecuteNonQuery();
                con.Close();
            }
        }
    }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Me.GridView1.Rows.Count > 0 AndAlso Session("myDatatable") IsNot Nothing Then
        Dim dt As DataTable = CType(Session("myDatatable"), DataTable)
        dt.Clear()

        For Each row As GridViewRow In Me.GridView1.Rows
            Dim firstName As String = (TryCast(row.FindControl("txtFirstName"), TextBox)).Text
            Dim lastName As String = (TryCast(row.FindControl("txtLastName"), TextBox)).Text
            dt.Rows.Add(firstName, lastName)
        Next

        GridView1.Visible = True
        GridView1.DataSource = dt
        GridView1.DataBind()
        Session("myDatatable") = dt
    End If
End Sub

Public Sub AddNewData()
    Dim dt As DataTable = New DataTable()
    If Session("myDatatable") IsNot Nothing Then
        dt = CType(Session("myDatatable"), DataTable)
    Else
        dt.Columns.Add("FirstName")
        dt.Columns.Add("LastName")
    End If

    Dim drow As DataRow = dt.NewRow()
    drow("FirstName") = ""
    drow("LastName") = ""
    dt.Rows.Add(drow)
    Session("myDatatable") = dt
End Sub

Public Sub BindGridview()
    If Session("myDatatable") IsNot Nothing Then
        Dim dt As DataTable = CType(Session("myDatatable"), DataTable)
        If(dt IsNot Nothing) AndAlso(dt.Rows.Count > 0) Then
            GridView1.Visible = True
            GridView1.DataSource = dt
            GridView1.DataBind()
        Else
            GridView1.Visible = False
        End If
    End If
End Sub


Protected Sub Add(ByVal sender As Object, ByVal e As EventArgs)
    For i As Integer = 0 To Convert.ToInt32(txtNo.Text) -1
        AddNewData()
    Next
    BindGridview()
End Sub

Protected Sub OnSave(ByVal sender As Object, ByVal e As EventArgs)
    For Each row As GridViewRow In GridView1.Rows
        Dim firstName As String = (TryCast(row.FindControl("txtFirstName"), TextBox)).Text
        Dim lastName As String = (TryCast(row.FindControl("txtLastName"), TextBox)).Text
        Dim conString As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
        Dim query As String = "INSERT INTO Student VALUES(@First,@Last)"
        Using con As SqlConnection = New SqlConnection(conString)
            Using cmd As SqlCommand = New SqlCommand(query)
                cmd.Connection = con
                cmd.Parameters.AddWithValue("@First", firstName)
                cmd.Parameters.AddWithValue("@Last", lastName)
                con.Open()
                cmd.ExecuteNonQuery()
                con.Close()
            End Using
        End Using
    Next
End Sub

Screenshot