InnerHTML in Div dynamic - HyperLink problem in ASP

Question

Hi,

I want dynamical add HTML on my div. I do this with:

            newsAllScroller.InnerHtml = newsAllScroller.InnerHtml + "<br><center><b>";
            List<DAL.News> newsList = DAL.NewsHandler.GetAllNews();
            foreach (DAL.News n in newsList)
            {
                newsAllScroller.InnerHtml = newsAllScroller.InnerHtml + "<br>" + n.Betreff + " - ("
                    + "<asp:HyperLink ID=\"news"+n.NewsID+"\" runat=\"server\" NavigateUrl=\"~/News.aspx?id=" + n.NewsID + "\""
                    + " CssClass=\"newsLink\">"
                    + "..."
                    + "</asp:HyperLink>"
                    + ")";
            }
            newsAllScroller.InnerHtml = newsAllScroller.InnerHtml + "</center></b>";

The HyperLink is not working (you cannot click it).

When I copy the hyperlink from the browser-source-code into an aspx-page it works, so it seems the syntax is all correct - but it doasn't work via code, why?

Answer 1

Because the aspx page is parsed only once before the output is sent to the browser. You can't print/output something and expect it to be parsed once more.

Answer 2

You cannot add server side control to HTML and think of it to behave normally, you would have to modify your code to

newsAllScroller.InnerHtml = newsAllScroller.InnerHtml + "<br>" + n.Betreff + " - ("
                    + "<a href ="/News.aspx?id=" + n.NewsID + "\""
                    + " class=\"newsLink\">"
                    + "... </a>"
                    + ")";

Answer 3

You should use a Repeater instead of appending text to InnerHtml. Something like this:

<asp:Repeater ID="myRepeater" runat="server" OnItemDataBound="myRepeater_ItemDataBound">
    <ItemTemplate>
        <br/><asp:Literal ID="myText" runat="server"/> - (<asp:HyperLink ID="myLink" runat="server" CssClass="newsLink" Text="..."/>)
    </ItemTemplate>
</asp:Repeater>

...and then in code-behind:

void Page_Load(object sender, EventArgs e) 
{
    if (!IsPostBack) 
    {
        myRepeater.DataSource = DAL.NewsHandler.GetAllNews();
        myRepeater.DataBind();
    }
}

void myRepeater_ItemDataBound(object sender, RepeaterItemEventArgs e) 
{
    if (e.Item.ItemType == ListItemType.Item || 
        e.Item.ItemType == ListItemType.AlternatingItem) 
    {
        var myText = e.Item.FindControl("myText") as Literal;
        var myLink = e.Item.FindControl("myLink") as HyperLink;
        var news = e.Item.DataItem as DAL.News;
        if (myText != null && myLink != null && news != null) 
        {
            myText.Text = news.Betreff;
            myLink.NavigateUrl = "~/News.aspx?id=" + news.NewsID;
        }
    }
}

I haven't tried the code myself but it should point you in the right direction. Check out the Repeater documentation for more information and examples.