Link button changing color when any data pager event takes place

Question

i have a alphabetic filter consist of 26 dynamically created link button on selecting any link button it is filtering the name of user's on the basis of alphabet and changing its color to orange to make it different from other linkbuttons it is working fine but if there are more number of user associated with a particular alphabet and on applying filter it is filtering the user on the basis of that alphabet and showing them in a list view on clicking the data pager next page or any other page number the link button changes its color to default color but i want to keep that highlighted until and unless other link button is selected my code

protected void Page_Init(object sender, EventArgs e)
    {
        // Adding Dynamically linkbuttons for all alphabets(i.e. A-Z)
        for (char asciiValue = 'A'; asciiValue <= 'Z'; asciiValue++)
        {
            LinkButton lbtnCharacter = new LinkButton();
            lbtnCharacter.ID = "lbtnCharacter" + asciiValue;
            divAlphabets.Controls.Add(lbtnCharacter);

            // Setting the properties of dynamically created Linkbutton.
            lbtnCharacter.Text = Convert.ToString(asciiValue);
            lbtnCharacter.CssClass = "firstCharacter";
            lbtnCharacter.ToolTip = "Show Tags starting with '" + Convert.ToString(asciiValue) + "'";
            lbtnCharacter.CommandArgument = Convert.ToString(asciiValue);
            lbtnCharacter.Command += new CommandEventHandler(lbtnCharacter_Command);
        }
    }



// For assigning default color to linkbutton text in page load
        foreach (var ctrl in divAlphabets.Controls)
        {
            if (ctrl is LinkButton)
            ((LinkButton)ctrl).CssClass = "firstCharacter";
        }

void lbtnCharacter_Command(object sender, CommandEventArgs e)
        {
            // Storing the values of pressed alphabet in viewstate.
            ViewState["Selected_Character"] = e.CommandArgument;
            LinkButton lbtnSelected = (LinkButton)divAlphabets.FindControl("lbtnCharacter" + e.CommandArgument);
            lbtnSelected.CssClass = "firstCharacter highlighted";
            txtTagFilter.Text = string.Empty;

            BindTagList();
        }

Answer 1

I hope I understood your question.

You are setting your Selected_Character item in the command handler and then setting the class of the button to highlight it. This only gets fired when the button is clicked, not when you move to the next page. Why not separate these two operations. Set the class of the link button on prerender if the Selected_Character matches. That way even when you page the link button will stay highlighted.

I would also set your selected character as a query string parameter, if someone copies and pastes a link to your page the button would not highlight and the correct data would not display.

Hope this helps.

Edit: Haven't tested the below but maybe it will get you started.

void lbtnCharacter_Command(object sender, CommandEventArgs e)
{
    // redirect to self with tag as qs parameter
    Response.Redirect(string.Format("{0}?tag={1}", Request.Url.GetLeftPart(UriPartial.Path), e.CommandArgument));
}

protected void Page_PreRender(object sender, EventArgs e) 
{
    if (Request.QueryString["tag"] != null) {
        LinkButton lbtnSelected = (LinkButton)divAlphabets.FindControl("lbtnCharacter" + Request.QueryString["tag"]);
        lbtnSelected.CssClass = "firstCharacter highlighted";
    }
}

N.B You will also need to change your BindTagList to use the query string also. I'm assuming you call this in the page load event.