Basically, I have created a custom control that uses an UpdatePanel, and as I understand it I need to use a ScriptManagerProxy to make it work ( since there should only be one ScriptManager per page, and is is declared in my .aspx page ).So, how do you use this beastie, is it just a matter of adding:
<asp:ScriptManagerProxy ID="ScriptManagerProxy3" runat="server">
</asp:ScriptManagerProxy>
to your control, or is there more to it?
Could anyone please post a link to a good tutorial/example set? I tried googling for this, but I didn't find anything useful...
Your control does not require a ScriptManagerProxy to work. You would only need a ScriptManagerProxy if you needed to add a ServiceReference or ScriptReference in your control. The ScriptManagerProxy allows you to do this without having to have knowledge about the page that is going to host your control. When the page is rendered, the properties of the ScriptManagerProxy controls are merged with those of the ScriptManager control on the host page.
Related
I am very new to asp.net and my job.
I was assigned a project to make a simple online order web application using asp.net c#.
The specification has been strictly defined (copied below)
Regarding the common content of the site, I need to make head, top and left(a search function)
"The design in /design/: Head.aspx Top.aspx Left.aspx"
-- Does that mean I am not allowed to use (nested) master page?
--- If so, how can I make a template without using master page?
Another option is to use the Server.Execute() method to render the contents of three separate pages into your base page if you have to use pages instead of usercontrols and still must have three separate pages rendered into one.
In the old days we did this with iis html includes.
If the head/top/left content is just basic HTML, then you could just put the HTML in a separate file and use an include link/reference in the original .aspx page.
If the content is all like a search function, then I agree with Henk's comment, create an .ascx User Control (which is really no different than an .aspx page with an .ascx extension) and then just reference that control on your .aspx page like this:
//put this at the top of your .aspx page
<%# Register src="usercontrols/YourControl.ascx" tagname="nameOfControl" tagprefix="ucControlName" %>
//then reference your control where you want it in your .aspx page
<ucControlName:nameOfControl ID="nameOfControl" runat="server" Visible="True" />
Here's an MSDN article on creating user controls: MSDN User Control
Maybe shoot the person who wrote the spec an email and ask why they have an issue with using a master page - this is kind of exactly why you would use one?!
JM
Say i have a MasterPage and two subpages, that are included through the ContentPlaceHolder.
Would it possible in AJAX to update the ContentPlaceHolder to change from 1 subpage to another?
And if so, are there any problems that i may encounter by using this type of interface?
You can't use ContentPlaceHolder control, since it will not be rendered in your page.
Please use div runat="server" and use div id to load the ajax content
All the scripts in the page will work fine loaded via ajax. There are few scenarios it will break/conflict with the parent page script. In that case, you can use iframe and set a src attribute
I have a content page which has a related master page.
I register a prefix <%# TagPrefix ..... and can load other custom controls at that namespace.
However, one particualar control at the same namespace, when added to the aspx page, breaks it.
The control in question inherits from asp:Panel, has a parameterless constructor, defines a few public accessors, and creates some standard child controls, and nothing much else.
Are there some fundamental restrictions to creating custom asp controls that I am breaking unknowingly?
Add the control back to the page. Delete the designer file for the page: .aspx.designer.cs
Then right click on the page and select Convert to Web Application. This should give you the actual error the page has when attempting to write the control definition to your designer file.
I suspect there is a compilation error in your custom control.
My control was attempting to access Page.Header which was null as the master page had not marked the tag with runat="server".
I guess that is a fundamental restriction that I was looking for...
The Scenario: I have an asp.net website where I show a div popup on page load for taking a few user details. When a user inputs the details, or closes the popup, I set up a flag cookie so that the popup is not displayed again for the user. The div is in the MasterPage so that it is displayed no matter on which page a user lands first time. The div contains an UpdatePanel which has all the controls required for taking the details. This whole functionality is working fine.
The Problem: Now this div popup is not showing(by setting display:none) on subsequent postbacks(which I want), but the html markup is still loading with the page unnecessarily adding to the page size. What I would idealy want to do is: Check if flag cookie is set. If no, show the popup, else remove the popup's markup from the page.
Now since the div is not a server control, I cannot possibly remove it and the all the controls inside it. So, I thought of removing the UpdatePanel from the page:
protected void Page_Load(object sender, EventArgs e)
{
if (Request.Cookies["flag"] != null)
{
if (Page.Controls.Contains(updpnl_contact))
{
Page.Controls.Remove(updpnl_contact);
updpnl_contact.Dispose();
}
}
}
But I guess this tends to work with dynamically added controls only, and since the control is added at Design Time, it is not being removed.
Is there any way I can achieve this?
If you add a runat="server" attribute to your <div> element, it will be available in the code-behind. You'll need an id on it as well. Then you can just toggle the Visible property. If this property is false, the control won't be rendered to the client (i.e. no HTML markup).
What you're trying to do is not at all the usual workflow. I tend to think that it will not work as it would mess up control tree, maybe even corrupt the viewstate and so on.
As a possible solution, you can put it's visibility to hidden in the code behind. This, in the contrary to the usual 'gut feeling', doesn't work like the css propery 'display:none' for example - instead the control will not even be rendered into the page when it's not visible. This may be the workaround for you.
Happy coding.
A more efficient approach would be to create the panel as a UserControl and load it dynamically in codebehind when it's needed, then add it to your page. E.g, in code:
MyPopupControl popup = (MyPopupControl)Page.LoadControl("/path/to/usercontrol.ascx");
PopupPanel.Controls.Add(popup);
Where PopupPanel is an empty <asp:Panel>. Then, not even the markup will need to be loaded/processed except when its needed.
There is no reason that all the code you use to display and process this panel couldn't also be in the usercontrol, isolating it from the master page.
Can you build the panel dynamically, based on the cookie setting?
I have an interesting problem when using partial page update in asp.net with scriptmanager and a update panel.
My scenario looks like this: I'm using the tab control from the ajax toolkit. I also implemented this control using lazy loading, so that when the page is loaded only the current tab gets loaded all the other tabs don't get rendered, because Im using an UpdatePanel (on a .ascx control) on each of these tabs and when a tab gets selected the updatepanel makes a async postback to load the content for a selected tab.
On one of my tabs Im using a combobox control from obout.com, and it doesn't work.
Now I know why it doesn't work. It doesn't work because the control is shown via a partial page refresh, but to correctly display the control it has to do some "magic" that is - register some .css and .js includes on the page (in the head I guess)....but because I load this control via async page refresh...it can't do these stuff.
What kind of workarround do you suggest?
Thanks!
Assuming you have done partial ajax updates in asp.net before, then you simply need to register a client block with the ScriptManager for when the partial update is triggered.
Without knowing your problem space, it's difficult to paste specific code for you, so instead I'll just suggest you read this and then ask more questions if you have them...
http://msdn.microsoft.com/en-us/library/system.web.ui.scriptmanager.registerclientscriptblock.aspx
BTW, if you're dynamically creating the controls as well as partially updating them, then you will also need to be very careful of your viewstate. This is a can of worms, so hopefully you are not and won't have to worry about it.
As I suspected you have to manually register the needed scripts for ajax controls to work in such a manner.
For example here is the solution for telerik controls:
http://www.telerik.com/help/aspnet-ajax/troubleshooting.html
Here is a solution using devexpress controls:
protected void Page_Load(object sender, EventArgs e)
{
DevExpress.Web.ASPxClasses.ASPxWebControl.RegisterBaseScript(this);
}
I didn't found a solution for obout.com controls.