How can I reset a asp.net form after postback? - asp.net

Question

I am trying after the btnCreate_OnClick event to reset the form to it's default value just like the first page_load. The problem is after PostBack, every textbox and other controls, reloads the ViewState value. I cannot deactivate viewstate because of server event on DropDownList selection. The only way I found so far is to Redirect to self after the click event, but this loads the page twice and is therefor a bad solution. I have try ViewState.Clear() and update the UpdatePanel, but was unsuccessful.
I could do a loop for all controls and set the txtXXXXX.Text == "", but I'm quite sure it's not the best idea.
Something like Page.Reset() would have been just perfect but it doesn't exist.
Any thought on this problem of mine?
Thanks

Answer 1

If workable, I usually just use Response.Redirect to reload the same page from scratch.
An initial GET request to a page usually costs less than subsequent POSTs anyway, so there's not much reason to avoid it.

Answer 2

We can reset the ASP.NET Form Page with just 2 lines of code
protected void Button_Reset_Click(object sender, EventArgs e)
{
Session["ViewState"] = null;
Response.Redirect("/Roster/DRAC/Create.aspx");
}

Answer 3

Self redirecting gets tricky because of viewstate.
There is an html input type "reset" for buttons, but I'm not sure what or any integration msft has put into viewstate/asp.net for this. It generally works for simple javascript forms.
ex:
<input type="button" value="Reset" onclick="document.<formId>.reset();">
from google ----^

Answer 4

One way, not necessarily ideal, is to reset the values to their defaults using Javascript. If it is a large form, it can be ugly, but will prevent the need to do a self-redirection.
You also might try Server.Transfer instead of Response.Redirect(/self/)

Answer 5

I dont know if this helps but i change the name of every input on the form that i want to get fresh values by using javascript before submiting the form, since the .net page can no longer match the values from the form to the controls for the page it reloads them as if there was no postback. i also append a new value to the form so i know what button submitted the form and use that logic to decide what to load into all the controls and how to process the form data of course.
$("#Bset").children().click(function() { //all the btns click function
$.each($("form").find("input"), function(e,v) { //could filter this to subset of inputs
$(v).attr("name", "_" + $(v).attr("name")); // ctrl1 becomes _cntrl1
});
$("form").append("<input type='hidden' id='b' name='b' value='" + $(this).text() + "' />").submit();
});
then in the code behind
protected void Page_Init(object sender, EventArgs e)
{
id = int.Parse(Request.QueryString["id"]);
bk = db.dc.getDetailBK(id).Single();
if (Request.Form.Count > 0)
doPostBack();
mrl = (from a in db.dc.getMetricQTD(id, null, null, loadSavedGoals) select a).ToList();
}
i can then do things in dopostback that process the form data, interact with the db etc. that may change the values mrl is loaded with and refresh the data in the inputs tied to mrl regardless of wether they were modified or not on the form.
the other alternative would be to tie some buttons to use a webservice to handle your db interaction then call window.location to refresh the page.
$.ajax({
url: "webservice/dbfunction?"
data: {which btn pressed, some form values etc...}
success: function() {window.location("samepage.aspx?id=xxx");}
...
});
this would also avoid having to response redirect on the server side.

Answer 6

In our case the best performance solution was to set manually for each control the default value in the click event ex:
textbox1.Text = null;
textbox2.Text = null;
This avoid the double page_load and the loop. We don't event have to update the UpdatePanel since it executes before render.
Maybe in a more complex web application we would have to Redirect as most people seem to accept this as a solution.
Setting per control the default value was better suited to our case.
Thank you