Creating Dynamic Controls in Asp.net C#, and caching the controls and binding the Data

Question

I am creating dynamic controls like textbox, dropdowns in Page_Init. After creating control I am binding data to the controls. When page postback happens I have to recreate the controls and rebind the data.

Is there any way I can cache the dynamically created control and just update the newest data to that control. For e.g. I Create the Textbox then set the value as "abc", when there is postback, i do not want to recreate the Textbox again, or just want to take the control from cache and want to update the latest value say "xyz" to that textbox.

Basically creating the controls first time, cache the control and bind latest data to control on postback.

Thanks Yogesh

score 0 · Answer 1 · answered Dec 20 '12 at 08:38

0

Add the code below in your init method

if(!IsPostBack)
{
    //Put your control initzilation here and it will not be triggered on a PostBack
}

You will need to have other logic thow that changes the txt value of the controls that need to be changed.

answered Dec 20 '12 at 08:38

Mattias Josefsson

1,147
1
7
22

Destrictor · Answer 2 · 2012-12-20T09:38:07.393

0

Creating controls in the Page_OnInit method should take care of the controls retaining their data.

If you're setting data in the code as well, make sure you encapsulate them in

if (!Page.IsPostBack)
{
    //set data here
}

this assures that only the first time the data will be set, instead of overriding every time.

Edit:

As a more complete example:

protected void Page_OnInit(object sender, EventArgs e)
{
    TextBox txt = new TextBox();
    //create more controls
    if (!Page.IsPostBack)
    {
        txt.Text = "initial value";
    }
    Page.Controls.Add(txt);
    //add other controls
}

edited Dec 20 '12 at 09:38

answered Dec 20 '12 at 08:44

Destrictor

752
1
4
15

Page.IsPostback is not going to help, because if the control is created dynamically like ASPX `code ` C# `protected void Page_Init(object sender, EventArgs e) { if (!IsPostBack) { TextBox txt = new TextBox(); txt.Text = "yeeelo"; Panel1.Controls.Add(txt); } else { } } ` On postback it will not show the control on page – Don Yogesh Dec 20 '12 at 09:23
@DonYogesh you're only supposed to set de data in !Page.IsPostBack, not create the control and add it. – Destrictor Dec 20 '12 at 09:34
Actually I do not want to recreate control on postback. The control should be created first time only, next time it should be taken from cache or session. is this possible? – Don Yogesh Dec 20 '12 at 10:05
@DonYogesh you could do `Session["txt"] = txt` in the !Page.IsPostBack and then after the if do `Page.Controls.Add(Session["txt"] as TextBox);`. But I very much recommend __AGAINST__ doing this: you'll create quite a big pressure on your server RAM if you're keeping all those controls in session (due to them only being removed if you're doing it manually, or user times out.) Creating controls every time again, reduces load on server RAM, due to using ViewState to store the content of the variables. – Destrictor Dec 20 '12 at 10:30
My basic aim to make the page faster, as creating dynamic controls and binding data take to much time. Do you any caching technique so that pages will load faster – Don Yogesh Dec 21 '12 at 03:10
I'm afraid I'm not that familiar yet with ASP.NET, so I can't help you there, sorry :( – Destrictor Dec 21 '12 at 08:45

score -1 · Answer 3 · answered Mar 04 '13 at 13:42

No EveryTime you have to create it

I do not know but i think that is bug of microsoft or something else but you have to create it everytime

some developers are suggesting that you have to create it in page_Preinit but you will not get any static table or panel control so where did you add control ?

Creating Dynamic Controls in Asp.net C#, and caching the controls and binding the Data

3 Answers3