How to add Control dynamically in an ASP.NET AJAX application

Most of us know how to create controls dynamically in an ASP.NET application. However a lot of users get confused while creating controls dynamically in an ASP.NET AJAX application. This is as the there is an async postback involved. Here's a very common technique to create controls dynamically in an ASP.NET AJAX application using ViewState


    <form id="form1" runat="server">


    <asp:ScriptManager ID="ScriptManager1" runat="server">


    <asp:UpdatePanel ID="UpdatePanel1" runat="server">


           <asp:Button ID="Button1" runat="server" Text="Create TextBoxes" onclick="Button1_Click" />







    protected void Button1_Click(object sender, EventArgs e)


        int cnt = 0;


        if (ViewState["txtBoxes"] != null)

            cnt = (int)ViewState["txtBoxes"];


        cnt = cnt + 1;

        ViewState["txtBoxes"] = cnt;



        for (int i = 0; i < cnt; i++)


            TextBox tb = new TextBox();

            tb.Text = "";

            tb.ID = "TextBox" + cnt;





    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs)

        Dim cnt As Integer = 0


        If ViewState("txtBoxes") IsNot Nothing Then

            cnt = CInt(Fix(ViewState("txtBoxes")))

        End If


        cnt = cnt + 1

        ViewState("txtBoxes") = cnt



        For i As Integer = 0 To cnt - 1

            Dim tb As New TextBox()

            tb.Text = ""

            tb.ID = "TextBox" & cnt


        Next i

    End Sub

About The Author

Suprotim Agarwal
Suprotim Agarwal, Developer Technologies MVP (Microsoft Most Valuable Professional) is the founder and contributor for DevCurry, DotNetCurry and SQLServerCurry. He is the Chief Editor of a Developer Magazine called DNC Magazine. He has also authored two Books - 51 Recipes using jQuery with ASP.NET Controls. and The Absolutely Awesome jQuery CookBook.

Follow him on twitter @suprotimagarwal.

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