CODEWITHSUNDEEP
asp.netwebforms
Aaz
Aaz

Reputation: 101

Dynamically updating a UserControl in ASP.net

I am new to Using ASP.net WebForms and I'm trying to dynamically update a UserControl which is added to a placeholder. The example I'm working on doesn't update, although the event 'onTextChanged' is getting triggered. Any pointers/suggestions welcome.

WebForm1.aspx

<%@ Page Title="Home Page" Language="C#" AutoEventWireup="true"
         MasterPageFile="~/Site.Master" CodeBehind="WebForm1.aspx.cs" Inherits="FFUC.WebForm1" %>

<asp:Content ID="BodyContent" ContentPlaceHolderID="MainContent" runat="server">
    <asp:Panel runat="server" ID="configPanel" Visible="true">

        Book Title:<asp:TextBox ID="tbxBookTitle" runat="server" OnTextChanged="updateBookTitle" AutoPostBack="true"></asp:TextBox>
        Book Author:<asp:TextBox ID="tbxBookAuthor" runat="server" OnTextChanged="updateBookAuthor" AutoPostBack="true"></asp:TextBox>

    </asp:Panel>
    <asp:Panel ID="UpdatePanel1" runat="server">

        <asp:PlaceHolder runat="server" ID="PlaceHolder1" />

    </asp:Panel>
</asp:Content>

WebForm1.aspx.cs

namespace FFUC
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        private UC.WebUserControl1 ctrl1;


        protected void Page_Load(object sender, EventArgs e)
        {
            // Add the control to the page
            ctrl1 = (UC.WebUserControl1)Page.LoadControl("UC/WebUserControl1.ascx");
            PlaceHolder1.Controls.Add(ctrl1);
        }

        protected void updateBookTitle(object sender, EventArgs e)
        {
            ctrl1.BookTitle = tbxBookTitle.Text;

        }

        protected void updateBookAuthor(object sender, EventArgs e)
        {
            ctrl1.BookAuthor = tbxBookAuthor.Text;
        }

    }
}

WebUserControl1.ascx

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="WebUserControl1.ascx.cs" 
            Inherits="FFUC.UC.WebUserControl1" %>

<h>Books:</h><br />
<asp:Literal runat="server" ID="lblBookTitle" Text="default" Visible="true"></asp:Literal>
<asp:Literal runat="server" ID="lblBookAuthor" Text="default" Visible="true"></asp:Literal>

WebUserControl1.ascx.cs

namespace FFUC.UC
{
    public partial class WebUserControl1 : System.Web.UI.UserControl
    {
        private string bookTitle = "book title";
        public string BookTitle { get; set; }

        private string bookAuthor = "book author";
        public string BookAuthor { get; set; }

        protected void Page_Load(object sender, EventArgs e)
        {
            lblBookAuthor.Text = BookAuthor;
            lblBookTitle.Text = BookTitle;

        }
    }
}

Upvotes: 0

Views: 1977

Answers (1)

Jonathan van de Veen
Jonathan van de Veen

Reputation: 1026

The reason you are not seeing your changed values in the user control is that any change you make only does a partial postback. This means the page is not rendered completely, hence your user control is not rendered. To make a scenario like this work with pure ASP.NET webforms is to use an updatepanel and trigger an update on that.

Upvotes: 1

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