RequiredFieldValidator error_message appears after form is submitted - asp.net

I submit form and the clear all the fields from code behind, and when page is re-rendered RequiredFieldValidator error message appears. I am submitting form and not using button's click event.
How can i avoid seeing validator message after form is posted back?
Thanks in advance.

You could add a Response.Redirect to a 'saved successfully' page rather than posting back to itself unless you need to stay on that page. But I will add a solution below if you want to remain on this page......
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
}
else
{
SaveRecordToDB();
Response.Redirect("/");
}
}
Assuming the submit page is the Default.aspx otherwise just redirect back to your own form page.

Related

Form submission without reloading page

I have a usercontrol containing a few textboxes and a submit button which runs inside a larger page, I have a few panels in the usercontrol so that when the user clicks submit the panels I toggle the visibility of the form panel with a panel saying "you have submitted". The problem I am having is that when the form is submitted it refreshes the whole page. I am wondering if there is any quick modification I can make to the usercontrol to have it only refresh itself without rewiring the form in ajax?
protected void Button1_Click(object sender, EventArgs e)
{
DatabaseConnection connection = new DatabaseConnection();
//Verify if entry exists
if (CheckValid())
{
//Register data
pnlSuccess.Visible = true;
}
else
{
pnlDejaRepondu.Visible = true;
}
pnlForm.Visible = false;
}
You can enclose content of the user control into an UpdatePanel.
UpdatePanel will cause partial postback of the user control content only, leaving the rest of the page intact.

asp.net dynamic user control button click issue

I made researching about this subject I could not find proper answer.
In my default.aspx page, I have a treeview. Codes are in default.aspx like below:
protected void Page_Load(object sender, EventArgs e)
{
}
protected void TreeView1_SelectedNodeChanged(object sender, EventArgs e)
{
Control ucont;
if (TreeView1.SelectedNode.Value == "Yeni Dönem")
{
ucont = LoadControl("usercontrols/yenidonem.ascx");
PlaceHolder1.Controls.Add(ucont);
}
else
{
ucont = LoadControl("usercontrols/tabloktar.ascx");
PlaceHolder1.Controls.Add(ucont);
}
}
I load user controls dnynmicaly. User controls are have button control. I can not fire user control's button click when I load it dynamcally. How can I solve this ?
Thanks.
First of all, I would not recommend adding control dynamically later than in Page_Load event. Other things to remember is that You should add it on each page load and assign unique ID value the control that does not change between postbacks.
In this case, the easiest way would be to always add both controls to the page and show appropriate one using Visibility property.
If that's not suitable for You, try to move the code from TreeView1_SelectedNodeChanged to the Page_Load event and load appropriate control on each postback until it should be changed to another one.
I haven't tested this, so if You have any issues when using thise answer, let me know in the comments and I'll try to help.

ASP.NET Login Controls, page postback and rendering on logout

I'm a bit puzzled by the behavior of the default ASP.NET Authentication controls, by its lifecycle to be precise.
In my MasterPage, I added a LoginView Control which displays the nice [Login] or [Logout] links. When I am logged in and click on [logout], I set up the control to perform a redirection to the homepage of the application.
Internally, when a click on "logout" happens, a postback is triggered. The following steps happen (among others of course):
The page that fired the postback is reinitialized
The page that fired the postback is reloaded
The LoggingOut event is fired
The LoggedOut event is fired
The page that fired the postback is PreRendered
The redirection happens
The target page is loaded (LoggedOut.aspx in my case)
On most of the pages, this works fine. But some pages expect some data to be initialized for their rendering to happens correctly. When this loggout postback occurs, the data isn't correctly initialized, but the page is still PreRendered which leads to some... "unexpected behavior" >_<
My question is thus twofold:
Why does this rendering step happens since the page won't be displayed at all?
Is there a way to prevent the rendering to happen?
Thanks a lot.
Tim
PS: here's a small VS2010 sample project showing you the call sequence & page lifecycle if you want to try it out for yourself http://dl.dropbox.com/u/11764136/LoginTest.7z
There is a way to prevent the actual rendering of the page.
Stop processing the current request when you redirect the page. This can be done by giving a true parameter to the Response.Redirect method:
Response.Redirect("http://somewhere", true);
You can also do this manually by calling Response.Close();
Are you using if(!isPostBack) test to control what should be rendered/re-initialized and what shouldn't?
Venemo's answer gave me an idea that seems to be working.
Instead of relying on the LoginStatus component to perform the redirection, I registered the MasterPage hosting the LoginStatus components to the LoginStatus.LoggedOut event and fire the redirection "per hand" before the PreRender step can be called.
protected void Page_Load(object sender, EventArgs e)
{
MasterLoginStatus.LoggedOut += new EventHandler(OnUserLoggedOut);
}
private void OnUserLoggedOut(object sender, EventArgs e)
{
Response.Redirect("~/LoggedOut.aspx", true);
}
I was concerned the LoginStatus component might remain dirty by doing this but sofar I haven't found any issue with it e.g. "works until proven otherwise".
Remains the question of "why the component behaves like this" but I guess it was a design decision that will remain unanswered.
Edit: this works fine until you get the same problem for the "login" action. Haven't found a way around this one yet.
I've got a serious problem with a DevExpress control (The report DocumentMap) which sometimes requests the whole report, bypassing the caching mechanism, when the end-user clicks on the logout link on the LoginStatus control. I've tried a lot of approaches to stop dead the "logout" postback so that the report won't get generated (some reports took 5 minutes to render, so the logout action sometimes took that long). I think this is similar to your problem: you don't want to do any heavy processing if the user is logging out. So I've tried a different approach: why didn't I recognize that the postback is indeed a logging out postback? All my pages inherit from a base page, so I've set this code in the base page:
public bool IsLoggingOut { get; private set; }
protected override void OnPreInit(EventArgs e)
{
base.OnPreInit(e);
var eventTarget = Request.Params.Get("__EVENTTARGET");
IsLoggingOut = eventTarget != null && eventTarget.Contains("HeadLoginView$HeadLoginStatus");
}
Now all I need to do in my page is to surround any heavy processing with a test of !IsLoggingOut... You could even do you redirect to the LoggedOut page without having to handle any events, just like this:
protected override void OnLoad(EventArgs e)
{
if (IsLoggingOut)
Response.Redirect("~/LoggedOut.aspx", true);
}
Even if you prefer to use the event handler to do that redirect, being able to know that the postback is indeed due to a logout click is a nice thing!
In my case, I was having this problem with the LoginStatus control. I can't see why it is a useful design to post back and Render the page when the user has clicked "logout". Through some tests, I found that I had to let the page go through its entire lifecycle, so Reponse.End() and Response.Transfer() did not work.
My solution was to add event handlers for the LoginStatus LoggedOut event, and then override the Render() method in the master page to do nothing if the user has logged out. I actually had the LoginStatus nested inside a user control that was then in the master page, so I had to bubble the event.
In my user control containing the LoginStatus control, I added an event handler for the LoggedOut event. In the UserStatus.aspx file:
<asp:LoginStatus runat="server" ID="loginStatusDefault" OnLoggedOut="loginStatusDefault_LoggedOut" ... />
Then in the code-behind:
public event EventHandler LoggedOut;
protected void loginStatusDefault_LoggedOut(object sender, EventArgs e)
{
if (this.LoggedOut != null)
this.LoggedOut(sender, e);
}
Now in the master page default.master, I have already included the UserStatus control:
<c:userstatus ID="ctlUserStatus" runat="server" />
and in the code-behind:
protected void Page_Init(object sender, EventArgs e)
{
ctlUserStatus.LoggedOut += ctlUserStatus_LoggedOut;
...
}
bool IsLoggedOut { get; set; }
void ctlUserStatus_LoggedOut(object sender, EventArgs e)
{
IsLoggedOut = true;
}
protected override void Render(HtmlTextWriter writer)
{
if (!IsLoggedOut)
base.Render(writer);
}
For me, the page rendering is what was bombing out when the user clicked "logout", so this took care of the problem for all pages.
What I did was have the logout link or onloggingout control just redirect to another page, "Logout.aspx" which then handles the log out code. Works great actually.
protected void LoginStatus1_LoggingOut(object sender, EventArgs e)
{
Response.Redirect("~/Logout.aspx");
}

ASP.Net Page Not Posting Back - Reloading Instead

I have a simple ASP.Net login page. When the login button is clicked, the page should post back and the even should be handled by my server-side event handler. Instead, the page simply reloads. Page.IsPostBack is false.
I've put breakpoints in the Page_Load/Init (where applicable) handlers of the Master page, the ASPX page and the UserControl (ascx). When I hit the Login button, instead of getting a post back and having my event handler called, I simply get the page load as if it was a fresh request.
But that's not the end of it! The login page takes a single query string parameter: Login.aspx?id=123456. The above failure occurs when using this parameter. However, if I enable URL Rewriting in order to make the query Login/123456, the error does not occur; I get a post back and my event handler is called in this instance.
So why am I not getting the expected behaviour from my page? What about the rewritten URL is making the problem go away?
Login Button is declared in LoginUserControl.ascx:
<asp:Button ID="SubmitLinkButton" runat="server" Text='Log In' OnClick="SubmitLinkButton_Click"></asp:Button>
And the handler in the code behind:
protected void SubmitLinkButton_Click(object sender, EventArgs e)
{
Authenticate();
}
SubmitLinkButton_Click is never called. :(
Edit (more code):
//Page_Init on the Master page
protected void Page_Init(object sender, EventArgs e)
{
if (HttpContext.Current.User.Identity.IsAuthenticated)
{
try
{
if (SessionFacade.User != null)
{
loginlabel.Text = "Logged in |";
LoginLink.Visible = true;
}
}
catch
{
FormsAuthentication.SignOut();
CacheFacade.RemoveSessionValues();
Session.Abandon();
Session.RemoveAll();
HttpContext.Current.Response.Redirect("~/Login.aspx");
}
}
else
{
loginlabel.Text = "";
LoginLink.Visible = false;
}
}
Page_Load on the ASPX page:
protected void Page_Load(object sender, EventArgs e)
{
if (this.IsPostBack.Equals(false))
{
/* Some business stuff that boils down to this: */
Session["company"] = Request["company"];
}
}
Page_Load on the Login Control:
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
//honestly, there's no code here
}
}
P.S: I need to keep the non-url-rewrite way of accessing the login page, because many users are still navigating to that URL.
P.P.S: Even if URL rewriting isn't enabled, the error still occurs.
Whenever I've seen this problem in the past it has usually been attributed to URL re-writing. I would usually reach for Fiddler to trace the HTTP activity. My hunch tells me after you click the button and see the POST request it will quickly be followed up by a 302 redirect to the login page.
You note that "The above failure occurs when using this parameter" of the login.aspx page. Are you certain there is no url-rewriter configuration that for example, may strip out any querystring values and do a redirect?
Try to check your caching policy. Possibly your request is cached
I cleared the history on my IE browser and the problem went away.
Did you try to use a different browser? Once I had a similar problem, and it solved by re-installing Firefox!

ASP.NET - Handling different PostBacks

I've got an ASP.NET page on which I've got a GridView which is part of a form. I've enabled editing on the GridView, so it causes a postback to the page.
I've also got a form on the page, which causes a postback when it's submitted.
Can someone tell me how I can distinguish between the two postbacks? When the form is submitted I need to handle that, but not for example when someone hits edit on the GridView.
Thanks.
Have you got some code which looks like
<asp:Button OnClick="ButtonEventHandler" />
<asp:GridView OnRowEditing="GridViewEditEventHandler" />
you could do what ever it was you need to do in the eventhander specific to the event you were interested in handling at that point.
protected void ButtonEventHandler (object sender, EventArgs e)
{
// do stuff from the button click event
}
protected void GridViewEditEventHandler(object sender, GridViewEditEventArgs e)
{
// do something else from the gridview event
}

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