I have a page that uses a master page, several RequiredFieldValidators, and the Web Toolkit autocomplete extender. The following code only shows the bare minimum of the page:
<%# Page Language="C#"
AutoEventWireup="true"
CodeFile="Login.aspx.cs"
MasterPageFile="~/master.master"
Inherits="Login" %>
<asp:Content id="Content1"
contentplaceholderid="ContentPlaceHolder1"
runat="server">
<asp:UpdatePanel ID="pnlUpdate" runat="server">
<ContentTemplate>
<div>
<asp:ImageButton class="submitButton"
imageurl="images/button_submit.gif"
id="btnSubmit"
runat="server"
onclick="btnSubmit_ServerClick"/>
</div>
</ContentTemplate>
</asp:UpdatePanel>
</asp:Content>
Code-behind:
protected void btnSubmit_ServerClick
(object sender, ImageClickEventArgs e)
{
//breakpoint here does not get hit
}
The <form runat="server"> tag is in the master page. The code above does not fire the onclick event. If I get rid of the master page and add a form tag to the page, it works. Is the form tag in the master page not supported, or is this supposed to work somehow?
alt text http://digitalcopy.warnerbros.com/images/mainmenu.gif?provider=00079&disc=03403AAA-1D20-47F2-91FA-5EE632832659
You can also check if your ImageButton does not trigger validation. If it does set its CausesValidation property to false (of course if it makes sense).
I had a similar issue (different scenario). I used Page.RegisterRequiresRaiseEvent(ImageButton) and my onclick event started to fire. Why I needed to do that? I don't know.
My solution was to set the ImageButton's CausesValidation to false.
I have a similar issue with the image button and found the root cause. You are using
"ib.ID = i + ":" + j;"
as the ID of the ImageButton, the ":" is illegal name to use, as you are creating it programmatically, ASP.NET allows it to be created.
At runtime, if you look at the HTML source of the page, you will see the special characters are either ignored or replaced with "_". So the page is unable to find the correct control, thus the event won't fire. Try changing the name with plain text, the event will fire.
ib.ID = i + ":" + j;
should be changed to
ib.ID = i.toString()+":"+j.toString();
If it still doesn't work try making use of the StringBuilder to buildup the ID and assign it later to ib.ID property
This is solution that worked for me
If you are binding through data bound controls then use OnCommand attr instead of OnClick attr
You have to have the control in a form runat=server somewhere, it can be in the Master page or the .aspx file. Double check that the master page form tag is runat=server
AutoEventWireup is the property that allows the syntax you are using. Double check the setting in the Master Page, WebForm and it can also be set in the web.config.
if that doesnt work, you can always explicilty code it (which I prefer)
<script runat=server>
protected override void OnInit(EventArgs e)
{
btnSubmit.Click += delegate(object sender, EventArgs e1)
{
};
base.OnInit(e);
}
</script>
UpdatePanel can mess with server side events being raised also, so try it without the UpdatePanel. And I am sure you have a ScriptManager in the Master Page
From the code you supplied, you seem to be missing the <asp:scriptmanager> from your page. You must do one of the following:
Have the <asp:scriptmanagerproxy> on the page and the <asp:scriptmanager> on the master page.
Have <asp:scriptmanager> on your page and no <asp:scriptmanager> on the master page.
Personally, I recommend having the <form> tag on the master page, but that's personal preference.
You can always try taking out the UpdatePanel and seeing if it works. I usually start without the UpdatePanel, get everything working the way I want and then add in the UpdatePanel and debug anything that causes.
The form in the MasterPage works for me so the ScriptManager/ScriptManagerProxy mentioned by #Keltex might be an issue, though I forget them sometimes and usually get away with it.
With the UpdatePanel the button's click event will be handled via Javascript, so you might grab FireBug or equivalent (depending on browser) and follow through what actually is happening. Is it tripping on the validation and you don't see it? Is there a JS error somewhere (the Control Toolkit isn't perfect always)? Is the page actually posting back at all and just not hitting the event handler?
On my webpage i am creating imagebuttons dynamically inside a table that is contained by an updatepanel. The buttons are created by this code:
for (int i = 0; i < 15; i++)
{
TableRow tr = new TableRow();
for (int j = 0; j < 20; j++)
{
TableCell tc = new TableCell();
ImageButton ib = new ImageButton();
ib.Click += new ImageClickEventHandler(ImageButton1_Click);
ib.ImageUrl = "../img/defaultCell.jpg";
ib.ID = i + ":" + j;
tc.Controls.Add(ib);
tc.Width = 25;
tc.Height = 25;
tr.Cells.Add(tc);
}
GameTable.Rows.Add(tr);
}
}
The image buttons will not trigger click events. HOWEVER, if the line 'ib.ID = ...' is commented out, they do! That single alternation seems to fix all the issues.
I have no idea why.
If anyone can explain this, and also tell me how to trigger events keeping the ability to set button id's, i'd be much thankful
I think it may have something to do with the fact your re-assigning the id's after creating & assigning the event handler?
Do you even need to assign the id's? - Surely this is done for you anyway? - True removing the 'ib.ID = i + ":" + j;'
Make sure you use OnClick rather than onClick
Your update panel could be messing with the postback. Try it without the UpdatePanel and see if that is the culprit.
I had the same problem that OnClick event of ImageButton was not firing. But the actual problem was, at form level, I had onSubmit="return false;"
I was facing the same issue, where I was dynamically creating an ImageButton and click of that event was not triggering. hence, i created the Image button in if (IsPostBack) . Now it is working fine. And even if the page gets refresh, the ImageButton will be retained.
I've just solved a similar issue where OutputCache was enabled. When changing from asp:ImageButton to asp:Button, the event is correctly fired. Probably asp:ImageButton has some bug with OutputCache.
After none of the above suggestions worked for me, I did one more try by calling the button creation in OnInit(). This fixed my issue and now the OnClick event is firing.
Related
I solved this problem in another instance by making some workaround but I want to get it clear this time as I understand my problem better.
My asp.net net page has a search functionality that searches the database based on 5 fields. The result is displayed in the gridview. The gridview is editable and I can update values. The problem is if I want to update multiple values, gridview won't allow it. So I included an extra column for checkbox. I have added a footer which has link to update all checked records.
Ok so here is the problem? How do I send the whole gridview to another page where I can capture the gridview values?
By default the page is submitted onto itself. If I change the default action page, the whole gridview and search, nothing will work.
So how do I submit the whole page (or part of it) to a different page other than the default action script?
I have not tried this specifically with a gridview, but I think a Cross Page PostBack should work. I have a search feature on my website as well and this is what I use.
Set the PostBackUrl of the Button that is causing the PostBack to the Destination page.
Let’s assume your source page is search.aspx and your destination page is SearchResult.aspx
Inside search.aspx:
<asp:Button ID="btnSearch" runat="server" Text="Search" CssClass="right"
ValidationGroup = "Search"
PostBackUrl="~/SearchResult.aspx"
onclick="btnSearch_Click"/>
The form will be posted to SearchResult.aspx. Inside SearchResult.aspx, you add this directive:
<%# PreviousPageType VirtualPath="~/Search.aspx" %>
And in the code behind, you can acess any control like this:
PreviousPage.<mycontrol>
Hope this help.
Have you tried using the Session? Just add the DataSource, or the Gridview itself to the Session and load it in the other Page and then Dispose() it.
Good luck!
UPDATE:
I have accomplished this in the past through Cross-Page Posting. This is how I did it now for testing purposes:
Default.aspx:
<asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" PostBackUrl="SearchResult.aspx" />
SearchResult.aspx.cs:
protected void Page_Init(object sender, EventArgs e)
{
if (PreviousPage != null)
{
if (Page.PreviousPage.FindControl("GridView1") != null)
{
GridView grid = (GridView)Page.PreviousPage.FindControl("GridView1");
grid.ID = "myGrid";
this.form1.Controls.Add(grid);
}
}
}
Hopefully this helps.
I have a ASP.NET page with 2 user controls registered. The first one has only one button in it. The second one is simple text and hidden on default. What I want is to make the second one visible when the button in the first one is clicked (that is on button click event).
ASP.NET page:
<%# Page Title="" Language="C#" CodeFile="test.aspx.cs" Inherits="test" %>
<%# Register Src="~/UC_button.ascx" TagName="button" TagPrefix="UC" %>
<%# Register Src="~/UC_text.ascx" TagName="text" TagPrefix="UC" %>
<asp:Content ID="Content1" ContentPlaceHolderID="MyTestContent" Runat="Server">
<UC:button ID="showbutton1" runat="server" />
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MyTestContent2" Runat="Server">
<UC:text runat="server" Visible="false" ID="text1" />
</asp:Content>
UC_Button.ascx.cs:
protected void button1_Click(object sender, EventArgs e)
{
Button btnSender = (Button)sender;
Page parentPage = btnSender.Page;
UserControl UC_text = (UserControl)parentPage.FindControl("text1");
UC_text.Visible = true;
}
What am I doing wrong? I get well known Object reference not set to an instance of an object. error on that last line of the code.
EDIT:
One thing I forgot to mention when first posting this. User controls are in different <asp:Content></asp:Content> controls (I edited upper example). If I put them in the same placeholder code works just fine. If I put them in the separate content placeholders I can't find them in any way with findcontrol. Why is that and how can I find them?
please check below:
UserControl UC_text = (UserControl)this.NamingContainer.FindControl("text1");
The FindControl method does not do a deep search for controls. It looks directly in the location you specify for the control you're requesting.
In your case, what you'll need to do is something like:
UserControl UC_text = (UserControl)Content1.FindControl("text1");
You can also see my question here: IEnumerable and Recursion using yield return that demonstrates a method of finding deep controls by type.
Ok I found solution until better one comes my way. The problem is, as Jamie Dixon pointed out (thank you Jamie):
The FindControl method does not do a deep search for controls. It looks directly in the location you specify for the control you're requesting.
So because I have user controls in different contentplaceholders I must first find targeted placeholder (where the user control reside) and then I can search for user control inside it:
protected void Dodaj_Feed_Panel_Click(object sender, EventArgs e)
{
ContentPlaceHolder MySecondContent = (ContentPlaceHolder)this.Parent.Parent.FindControl("MyTestContent2");
UserControl UC_text = (UserControl)MySecondContent.FindControl("text1");
UC_text.Visible = true;
}
what really annoys and confuses me is the this.Parent.Parent part because I know it's not the best solution (in case I change the hierarchy a bit this code will break). What this part of code actually does is that it goes two levels up in page hierarchy (that is page where both user controls are). I don't know what the difference with this.Page is because for me it means the same but is not working for me.
Long term solution would be something like server side "jQuery-like selectors" (it can found elements no matter where they are in hierarchy). Anyone has a better solution?
use the id of user control，then put the controls (e.g Textbox) inside panel then
try this code from the main page
example:
TextBox txt = (TextBox)showbutton1.FindControl("Textbox1");
for updating with udpatepanel:
TextBox txt = (TextBox)showbutton1.FindControl("Textbox1");
txt.Text="Hello World!";
((UpdatePanel)showbutton1.FindControl("UpdatePanel1")).Update();
I have some linkbuttons to update my gridview which is in the middle of the page. Everytime I hit edit or delete etc the window scrolls to the top on the page that gets posted back. I want it to stay focused on the grideview. I have tried a javascript function but for some reason it did not work.
(edit: the following works as far as scrolling is concerned but prevents postback)
here is what I tried
<script type="text/javascript" language="javascript">
function goto() {
window.scrollTo(10, 1100);
}
</script>
<asp:LinkButton ID="lbtnGo" runat="server" OnClientClick="javascript:goto();return false;">GO</asp:LinkButton>
source
How can I do this?
Did you try with <%# Page MaintainScrollPositionOnPostback="true" %> in the page declaration?
Regards
Client-side event fires before server-side. So even if you scroll window to correct position - after postback you will be returned to the top. You can add the following code to your server-side LinkButton click event handler:
if (!this.IsStartupScriptRegistered("ScrollToGrid"))
{
String scriptString = "<script language=\"JavaScript\">";
scriptString += "window.scrollTo(10, 1100);";
scriptString += "</script>";
this.RegisterStartupScript("ScrollToGrid", scriptString);
}
this will add javascript block to your page after postback
There are, depending on the .NET framework properties available that can help one out:
ASP.NET 1.x: use SmartNavigation. ASP.NET 2.0: use MaintainScrollPositionOnPostBack. Use an UpdatePanel control to asynchronously update parts of a page
and the best way for this is UpdatePanel control to asynchronously update parts of a page
I am having an ASP.NET page with one Asp.net button control and a normal html link (anchor tage) I want to invoke the postbackl event of asp.net button control when someone clicks on the link.
I used the below code
<a href="javascript:myFunction();" class="checkout" ></a>
<asp:Button ID="btnCheckout" runat="server" Visible="false"
onclick="btnCheckout_Click" />
and in my javascript i have
function myFunction()
{
var strname;
strname = "Test";
__doPostBack('btnCheckout','OnClick');
}
But when runnin gthis , i am getting an error like __doPostBack is undefined
Can any one tell me why it is ?
Thanks in advance
This anyway wouldn't have worked. When you make your .NET control invisible by using 'Visible="false"' it isn't rendered, that means not available at the client.
Back to your question.
1- Where is myFunction defined? Between the tag?
2- Are there more .NET controls on the page? If there aren't any other .NET controls, .NET doesn't add all the scripts that are required for postbacks and stuff.
Why not do the following (based on TheVillageIdiot answer):
<asp:LinkButton ID="lbtnCheckout" runat="server" CausesValidation="false" OnClick="lbtnCheckout_Click" CssClass="checkout" />
With the above example you don't need the fake button and make it invisble. You still can do your postback. Way more cleaner approach I would say.
First of all I tried your code and also not get anything like __doPostBack, then I added another button on the page which was visible but it was all the same. Then I added a LinkButton and got __doPostBack method. You can do post back from javascript but then EventValidation is problem, as it does not allow this kind of thing. I had to use the following to overcome it and it worked:
protected override void Render(HtmlTextWriter writer)
{
ClientScript.RegisterForEventValidation(
new PostBackOptions(btnCheckout, "OnClick"));
base.Render(writer);
}
I think I'm bit incoherent in answering so I'll mark it as wiki :)
I can't seem to be able to disable ViewState for controls that I add to a page dynamically.
ASPX
<%# Page Language="C#" AutoEventWireup="true" CodeFile="Page1.aspx.cs" Inherits="Page1" EnableViewState="false" %>
...
<asp:PlaceHolder ID="DropDownPlaceHolder" runat="server" EnableViewState="false" />
<asp:Button ID="Submit" runat="server" OnClick="Submit_OnClick" Text="Click Me!" EnableViewState="false"/>
...
ASPX.CS
protected override void OnInit(EventArgs e)
{
DropDownList dropDown = new DropDownList();
TextBox textBox = new TextBox();
textBox.EnableViewState = false;
dropDown.Items.Add("Apple");
dropDown.Items.Add("Dell");
dropDown.Items.Add("HP");
dropDown.AutoPostBack = true;
dropDown.EnableViewState = false;
DropDownPlaceHolder.Controls.Add(dropDown);
DropDownPlaceHolder.Controls.Add(textBox);
base.OnInit(e);
}
If I can't disable ViewState on these controls, then I can never programmatically override what a user has entered/selected.
I've tried placing this code in OnInit and Page_Load, but the effect is the same in either location -- ViewState is enabled (the DropDownList maintains selected value and TextBox retains text that was entered).
So, how can I disable ViewState and keep it from populating these controls?
Thanks!
Thanks for your response.
Unfortunately, this isn't a workable solution in my situation.
I will be dynamically loading controls based upon a configuration file, and some of those controls will load child controls.
I need to be able to turn the ViewState of controls off individually, without the need to code logic for loading controls in different places (in OnInit vs. LoadComplete
method).
#This Mat
It seems the post(back) will send the selected value, even if a control has it's viewstate turned off.
Yes. The post will always send a controls selected/current value. That's a behavior of HTTP form posting and nothing to do with ASP.NET control/view state.
What you are seeing there is the ControlState which was introduced with .Net Framework 2.0. It is designed to store the absolute minimum information for a control to work, such as the selection in your DropDownList and the text in your TextBox. Properties which are only related to appearance, such as BackColor, are still persisted within the ViewState.
Unlike ViewState you can't turn ControlState off.
I can only assume this is to avoid confusion from end-users when controls do not do what they are supposed to if they disable ViewState without understanding the consequences.
It's a "feature" -- http://support.microsoft.com/?id=316813
Thanks, Microsoft!!
I tested this a bit and found it a little odd. It seems the post(back) will send the selected value, even if a control has it's viewstate turned off.
I did find a good solution around it though, is that if you handle everything after the init and load, you will reload your control after the viewstate has been processed and it will thus, reset the values.
I used the LoadComplete event, example below:
Public Sub Page_In(ByVal sender As Object, ByVal e As EventArgs) _
Handles Me.LoadComplete
Dim ddl As New DropDownList()
ddl.EnableViewState = False
ddl.Items.Add("Hello")
ddl.Items.Add("Stackoverflow")
phTest.Controls.Add(ddl)
End Sub
Hope this helps.