为什么我的功能不起作用？

Question

I use Ajax toolkit.I want create text editor for HTML codes. I found .css file in html link tags and for each of these files, create a LinkButton. I want when user click linkbutton .css file open in editor. I write this code:

string textHtml = "";
List<string> listTextHtml = new List<string>();
protected void Page_Load(object sender, EventArgs e)
{
    AsyncPostBackTrigger d = new AsyncPostBackTrigger();

    if (IsPostBack)
        return;
    StreamReader re = new StreamReader(string.Concat(Server.MapPath("/"), "\\Engine\\TextFile1.txt"));
    while (re.Peek() > 0)
    {
        txtHtmlCode.Content = txtHtmlCode.Content + re.ReadLine() + "\n";
    }
    textHtml = txtHtmlCode.Content;
    re.Close();
    string temp = textHtml;
    while (temp.Contains("link"))
    {
        string s = temp.Substring(temp.IndexOf("link"), temp.IndexOf("/>"));
        temp = temp.Substring(temp.IndexOf("/>") + 2);
        if (s.IndexOf(".css") >= 0)
        {
            s = s.Substring(s.IndexOf("href=\"") + 6);
            listTextHtml.Add(s.Substring(0, s.IndexOf("\"") - 1));
        }
        //temp = temp.Substring(temp.IndexOf("href="));
        //temp = temp.Substring(temp.IndexOf("\"") + 1);
        //listTextHtml.Add(temp.Substring(0, temp.IndexOf("\"") - 1));
        //temp = temp.Substring(temp.IndexOf("\"") + 1);
    }
    int i = 0;
    hfString.Value = "";
    foreach (var item in listTextHtml)
    {
        //HtmlGenericControl li = new HtmlGenericControl("li");
        LinkButton lb = new LinkButton();
        lb.ID = i.ToString();

        lb.Text = "Link - " + i.ToString();
        //lb.Click += ltnCssLoad_Click;
        lb.Click += new EventHandler(this.ltnCssLoad_Click);
        //li.Controls.Add(lb);
        phTags.Controls.Add(lb);
        d.ControlID = i.ToString();
        d.EventName = "Click";
        //udpMain.Triggers.Add(d);
        i++;
        hfString.Value += item + "|";
    }
}

when click the linkbutton this function must run:

protected void ltnCssLoad_Click(object sender, EventArgs e)
{
    LinkButton ClickedLink = (LinkButton)sender;
    string[] listText = hfString.Value.Split('|');//string.Concat(Server.MapPath("/"),
    StreamReader re = new StreamReader(string.Concat(string.Concat(Server.MapPath("/"), listText[int.Parse(ClickedLink.ID)])));
    txtHtmlCode.Content = "";
    while (re.Peek() > 0)
    {
        txtHtmlCode.Content = txtHtmlCode.Content + re.ReadLine() + "\n";
    }
    re.Close();
}

but when I use break point in function ltnCssLoad_Click , this function not work when I click in linkbutton. How can I fix this?

Answer 1

This is not working because when you click link button or any dynamically added control it causes post back and you have "return"ed in page load event handler if IsPostBack is true.

The pain with using dynamic controls is that you have to recreate them every time (first request as well as subsequent post backs).

Restrict file reading to first request (ie put it in !IsPostBack condition) and let link buttons' creation code run after that.