ASP.NET

Re: Avoid Duplicate record insertion on page refresh(F5)

16-Feb-10 2:33

There is no straight forward way to avoid this without refreshing the page. The simplest way to go is to use Server.Transfer or Response.Redirect from the server after completing the save.

Since you wish to display a message then you can do it in either of the two ways.
1. Simply put a button to refresh the data above the data section and hope that users use this instead of the browsers' refresh button [F5]. In most cases, the users would use this instead of F5. If its a intranet application then you can even educate your users on the same. You could also put a message next to the button telling them to use this rather than F5.

2. After you complete the save and give the message, just push a client script that would refresh the page using say "window.self.location=" after waiting for a specified time say 5 seconds. That way, your message would be visible for 5 seconds and the postback would be cleared.

amitamit09916-Feb-10 3:00

amitamit099

16-Feb-10 3:00

i appreciate your solution but there is some problem in your solution.

1)i cant forced any user to use only refresh button.user can click any button.

2)second option is seen good but it is not a appropriate solution of my problem.
i want to display message when submit button will press,and when user click on refresh(F5) then message will we clean.

Re: Avoid Duplicate record insertion on page refresh(F5)

bgates197016-Feb-10 4:55

bgates1970

16-Feb-10 4:55

How about clearing the fields/variables after insertion? Then before inserting you validate that data to make sure it exists.

Re: Avoid Duplicate record insertion on page refresh(F5) [modified]

Member 103390716-Feb-10 9:29

Member 1033907

16-Feb-10 9:29

I invested some time investigating this and the only solution I found working is based on some interaction between client data (ViewState, ...) and server data (Session, ...). Why:

- I don't accept solutions like "Check if the record already exists in the database" etc., because this is limited to inserting data to database, useless for any other scenario. Plus it has other flaws.
- You can't rely solely on client data (by this I mean data received from the client, like ViewState, POST data etc.), because when the user hits F5, the same request with the exact same data is sent to the server - if you accept the request as genuine the first time (and insert some data to the database), there is no way to dismiss it the second time (after refresh) because the data is exactly the same, so any deterministic algorithm for refresh detection can't possibly work. Half the people in the posts above don't realize this.
- I don't accept page redirections, because they either don't work (see above, try yourself if you don't believe) or if you try hard and make them work, they destroy the page state so it may be difficult to keep track of where the user was in the application, etc.

This eliminates all the solutions from the above posts. Like I said, the only way I got to work was to maintain a state-interaction between some Session variable (or any server piece of data) and ViewState variable (or any client piece of data). During normal requests, you keep these in sync and when you receive some Insert request, you compare them and check if they are in sync. If they are, the request is genuine and you can perform the insert. If the user hits Refresh (F5), the ViewState data is old compared to the server data and you recognize the request as refresh and do not perform the insert.
I event made a small component for this purpose, which you simply add to the page and then call BlahBlah.IsRefresh whenever you need. I can publish it somewhere if anyone cares. I think Microsoft should have long ago addded this functionality to the Framework so we could call Page.IsRefresh just like Page.IsPostback.

modified on Wednesday, February 17, 2010 3:56 AM

Re: Avoid Duplicate record insertion on page refresh(F5)

amitamit09916-Feb-10 19:03

amitamit099

16-Feb-10 19:03

I am developing a mail application. Through smtp I am sending mail.
I work properly. Mail will send successfully.
After sending mail I am display message your mail has send successfully(which is show after the mail has been send).
But the problem is that when I press F5 button then mail again send.
And it is sending again and again when ever I press F5
I donot want to send mail again when pressing F5 and message will also will display after mail has been send.
I tray to redirect the page it solve my problem to resend the page but in this situation massage will not display.

Plz can u help me

bind Checkboxes

m@dhu15-Feb-10 22:03

m@dhu

15-Feb-10 22:03

Im having around 30 Checkboxes in page i need to insert name of those checkboxes in a single column(seperated by comma) of table into db and also need to bind them from db
how can i do it in simple way....

Re: bind Checkboxes

Brij15-Feb-10 22:16

Brij

15-Feb-10 22:16

I dont think there is simple way except making a temp collection after getting data from db and again costomise the names according to your requirement.

Cheers!!
Brij

Re: bind Checkboxes

Dinesh Mani15-Feb-10 22:17

Web Deployment error for WebUserControl event [modified]

15-Feb-10 22:17

I think you can use a CheckBoxList for this. Just get the items from the database, split it on "," and get a array/collection and bind it in..

BTW, why would you want to save the names of checkboxes to the db?? It should be a pre-defined list editable through the DB or other means only.

Re: bind Checkboxes

keyur satyadev15-Feb-10 22:52

keyur satyadev

15-Feb-10 22:52

in CS page split it with ',' and using for loop bind the each checkbox. now when you want to save in DB again using loop, save in one string (comma separated)(both Id and Text), pass this string to DB and using while loop split it with comman and update the text with particular Id.

let me know if you have any issues.

Regards
Keyur Satyadev

K V Sekhar15-Feb-10 21:29

15-Feb-10 21:29

Hi All,

I am deploying my website by using add webdeployment project.
But in my website i have used the WebUserControls in my website. The WebUserControls events are handled in form[which contains WebUserControl] through Delegates & Event Handlers.

These events of WebUserControl have been initialized at form Default.aspx Page Init event.

When i build the Project it gives no errors, the site runs perfectly...

But when build the Deployment project i got a compilation errors of WebUserControl events where i initilized at form Default.aspx page init event.

Its giving error message like 'MyUserControlUC' could not found are u missing add reference.

For sample:
==========

MyUserControlUC.ascx

<pre>

<scrpt runat="server">
//delegate
public delegate void DropDownSelectedIndexChanged(object sender, EventsArgs e);
//event
public event DropDownSelectedIndexChanged IndexChanged;
//call the event
protected void ddl_items_SelectedIndex_Changed(object sender, EventsArgs e)
{
if(IndexChanged != null)
IndexChanged(sender,e);
}

<asp:dropdownlist id="ddl_items" runat="server" autopostback="true" onselectedindexchanged="ddl_items_SelectedIndex_Changed">

Default.aspx

<%@ Register TagPrefix="uc1" TagName="SampleUserControl" Src="~/MyUserControlUC.ascx" %>
<html>
<head></head>
<body>
<form runat="server">
<uc1:SampleUserControl BackColor="Gray" id="SampleUserControl1" runat="server"></uc1:SampleUserControl>
</form>
</body>
</html>

Default.aspx.cs

<pre>

protected override void OnInit(EventArgs e)
{
base.OnInit(e);
InitializeComponent();
}
private void InitializeComponent()
{
this.Load += new EventHandler(this.Page_Load);
SampleUserControl1.IndexChanged += new ASP.MyUserControlUC.SelectedIndexChanged(ddl_items_SelectedIndexChanged);//Here i am getting error while building deployment project.
}

private void ddl_items_SelectionIndexChanged(Object sender, EventArgs e)
{
//Code here to handle ...
}

Thanks & Regards

modified on Tuesday, February 16, 2010 8:06 AM

Dinesh Mani15-Feb-10 21:47

15-Feb-10 21:47

If you are having the UCs in different project from the main web site, then check if the Build order of the solution is set correctly and check if you have enabled compiling the primary assembly and all it dependencies.

HTH!

K V Sekhar15-Feb-10 21:55

15-Feb-10 21:55

Hi Dinesh,

Thanks for ur reply.

But the WebUserControl are in sample project.i.e, in main website it self

Regards,
kv sekhar

Dinesh Mani15-Feb-10 22:07

15-Feb-10 22:07

mm, try qualifying the UC with it relative path like so -

<%@ Register TagPrefix="uc1" TagName="SampleUserControl" Src="~/MyUserControlUC.ascx" %><br />

This denotes taht "MyUserControlUC" is available in the application root folder.

K V Sekhar15-Feb-10 22:58

Re: Web Deployment error for WebUserControl event [modified]

15-Feb-10 22:58

Hi Dinesh,

<%@ Register TagPrefix="uc1" TagName="SampleUserControl" Src="~/MyUserControlUC.ascx" %>

is right, in the post i wrote wrong. In register tag no error.

Problem with at Initilization of UserControl events in form.

any suggestions is appreciated..

Thanks & regards,
kv sekhar

Dinesh Mani15-Feb-10 23:03

15-Feb-10 23:03

Can you post the exact compilation message and the reference line number?

Well, I can't think of whats going wrong. Hard luck.

modified on Tuesday, February 16, 2010 5:21 AM

K V Sekhar16-Feb-10 2:04

16-Feb-10 2:04

Hi Dinesh,

Sorry for late response...

The exact error message is

1.System.Web.UI.UserControl does not contain a definition for 'IndexChanged' and no extension method 'IndexChanged' accepting a first arguement of type 'System.Web.UI.UserControl' could be found.(are u missing a using directive or an assembly reference)

2.The type or namespace name 'MyUserControlUC' doesn't exist in the namespace 'ASP' (are u missing an assembly reference?)

This error i got at Default.aspx.cs page

private void InitializeComponent()<br />
{<br />
  this.Load += new EventHandler(this.Page_Load); <br />
  SampleUserControl1.IndexChanged += new ASP.MyUserControlUC.SelectedIndexChanged(ddl_items_SelectedIndexChanged);//Here i am getting error while building deployment project.<br />
}

regards,
kv sekhar

Dinesh Mani16-Feb-10 2:24

16-Feb-10 2:24

From the first post, your IndexChanged event is of type (Delegate) DropDownSelectedIndexChanged. Where as you are trying to assign it to a delegate of type MyUserControlUC.SelectedIndexChanged. You should actually be assigning it to MyUserControlUC.DropDownSelectedIndexChanged.That is what the error message implies too.

You have used the namespace qualifier "ASP" to assign the IndexChanged event handler. Is this namespace correct??

Try the changes, it might do the trick.

HTH

K V Sekhar16-Feb-10 3:17