Does anyone know how in ASP.Net's TreeView control, to have a custom style applied to an Expanded node? I have many root nodes and want the Expanded nodes to have a different background.
There is no way of doing this with out of the box controls and this goes for alot of MS ASP.NET controls, however there is an adapters project on codeplex that makes your ASP.NET controls CSS-friendly:
http://www.codeplex.com/cssfriendly
Its pretty straight forward but ask again if you need any help setting it up.
I didn't want to deviate from the original control, so I ended up writing some JavaScript that would modify the tree via node structures on page load.
Related
I guess this is a lot of questions bundled into one post.
I want to build a wizard-like control which looks similar to the TabContainer
But I need certain customizations. These would be like I'd want to associate some help text with the TabPanel. So I imagine I'd want to write my markup like below for the tabpanel:
<cc1:MyTabPanel ID="mtp1" runat="server">
<HelpTextTemplate>
This is your step 1 which is about ...
</HelpTextTemplate>
<ContentTemplate>
Content goes here...
</ContentTemplate>
</cc1:MyTabPanel>
So what do you do to make markup like that...? And how would our control from code behind be able to access data between HelpTextTemplate - which may contain server controls and all?
Moreover, notice that there is a button called 'Save' in the above pic. The user simply drags and drops into the tab panel. And when the user double-clicks on it we have a method stub generated in the code behind (which belongs to the aspx page). How is all of this achieved?
And to cap the whole solution off, I realize we have to wire some javascript to simulate that tab functionality. There is css here too (Notice the images behind the tabs - the gradient, etc). The aspect that I am looking at is making this into a control that the users can use out-of-box just like the toolkit's tabcontainer control. Hence the css/javascript should kind of be bundled. How to achieve this?
Edit:
I am also interested in making the control designer (design-time interaction) part. I am looking for functionality the same way we have for the asp.net wizard control. I have found answers to some of the questions I had above will add it when I find time.
For embedding a script or image to the asp.net custom control I found a solution mentioned in the below site:
Embed js resource with custom asp.net control
What I suggest here it may sound too much, but I can not think other easy way for what you ask and the way you won it.
Grab the source code of the TabContainer, clone it, and make all your custom settings base on that source code. The first steps is to get the full source code of this asp.net toolkit and make a build that working. The second step is to add a clone of the TabControl, with new names. Then you work on this clone to make your changes as you wish for. The final step is to try to separate your custom control in a stand alone library if this is possible.
Download the latest version of the full asp.net ajax control toolkit
http://ajaxcontroltoolkit.codeplex.com/SourceControl/list/changesets
Here you can see online the source code for the TabContainer only
http://ajaxcontroltoolkit.codeplex.com/SourceControl/changeset/view/2c482e5ad6c4#Server%2fAjaxControlToolkit%2fTabs%2fTabContainer.cs
The control you are trying to build is not incredibly complex, but it does involve a number of different techniques.
I would suggest creating your own control from scratch rather then inheritting an existing one. Probably using CompositeControl as the base would be best since it gives you a lot of flexibility.
For HelpTextTemplate/ContentTemplate you'll want to create some ITemplate containers, take a look at this article http://msdn.microsoft.com/en-us/library/aa478964.aspx on how to set these up. Since you may want to access the contents/controls in HelpTextTemplate take a look at this article for how to access them: ASP.Net ITemplate - ways of declaring.
For the tabs, since this is custom, I would probably avoid AjaxControlToolkit. Instead I would include a reference to jQuery UI and use jQuery UI Tabs: http://jqueryui.com/demos/tabs/. Your CompositeControl just needs to output some divs, ul/li elements and you'll be good to go for making the tabs.
If you are fixated on using the AJAX Control Toolkit Tabs then you still can. You'll need to instantiate an instance in your custom control, add it to the control tree, and then use a technique like this: http://msdn.microsoft.com/en-us/library/0e39s2ck.aspx to transfer the contents of your template to the tab pages.
Being able to drag and drop a control from the toolbox onto your page is simple; if your server control library is already part of the same solution as your website then it will just show up. Worst case scenario you can use the Add Items option and add the DLL by browsing for it. As for how the Click event is created when you double click a button, that is done through an attribute on the class, take a look at this tutorial on setting up default events: http://msdn.microsoft.com/en-us/library/43sxkdeb.
As for embedding javascript into the library, these two questions cover how to do this specifically for jQuery UI, if you choose to go some other route it should still be pertinent: How to embed jquery library in asp.net custom server control?, http://forums.asp.net/t/1599621.aspx/1.
As for design time support, try reviwing Microsofts article on this (includes a sample): http://msdn.microsoft.com/en-us/library/aa478960.aspx or this CodeProject article on it: http://www.codeproject.com/Articles/9227/ASP-NET-Server-Control-Design-Time-Support.
Hello I am trying to lear how to create Dynamic User Controls in asp.net.
I just know that this type of controls are created or loaded at run time.
Someone knows a good tutorial about this topic?
thanks in advance,
The best thing you can learn about dynamic controls in ASP.Net webforms is how to avoid them. Dynamic controls in asp.net are filled with pitfalls. I almost always recommend one of the following alternatives:
Place a reasonable fixed number of controls on the page, and then only show the ones you need.
Figure out the source for the dynamic controls and abstract it out to a datasource (array, ienumerable, list, etc) that you can bind to a repeater, even if it's just a call to Enumerable.Range().
Build a user control that outputs the html you want, bypassing the entire "controls" metaphor for this content.
If you really must work with dynamic controls, it's important to keep the stateless nature of http in mind, along with the asp.net page life cycle. Each adds it's own wrinkle to making dynamic controls work: the former that you need to create or recreate the controls every time you do a postback, and the latter that you need to do this before hitting the page load event - usually in page init or pre-init.
Typically what people are talking about here is the dynamic instantiation and addition of a control to a placeholder.
For example
Control ControlInstance = LoadControl("MyControl.ascx");
myPlaceholder.Controls.Add(ControlInstance);
The above instantiates MyControl.ascx and places it inside of a placeholder with id of myPlaceholder.
I agree with #Joel by knowing the page lifecycle, the stateless nature in mind etc it is possible to avoid the pitfalls. The main things to watch out for, which I have had to do, are:
Page_Init – initialise the controls that are on the page here as they were the last time you rendered the page. This is important as ViewState runs after Init and requires the same controls initalised the same way as the way they were previously rendered. You can load the control using the code from #Mitchel i.e.
Control ControlInstance = LoadControl("MyControl.ascx");
myPlaceholder.Controls.Add(ControlInstance);
Page_Load – Load the content of the controls in here as you would with any control that isn’t dynamically loaded. If you have kept a reference to them in your page_init they will therefore be available here.
Keeping to this structure I haven’t had too much difficulty as this is appears to be the way that ASP.NET was designed to work, even if all the samples on MSDN don’t do it this way. The biggest thing that you then have to watch is tracking what state the page was in in regard to the controls that you have had rendered.
In my case it was take the section number of the multipage survey and reload the questions from the database, so all I had to do was track the currently rendered section number which wasn’t difficult.
Having said all that if you are using dynamic controls just to show and hide different views of the same screen then I suggest you don’t use them. In this case I would much rather use either user controls (with the inappropriate ones hidden), placeholders to mark areas that aren’t to be rendered yet, or separate pages/views etc. as that way you keep the pages to a single responsibility which makes it easier to debug and/or get useful information from the user about which page they were on.
The Microsoft article is very good, but the best article that I have been read is in the bellow link:
https://web.archive.org/web/20210330142645/http://www.4guysfromrolla.com/articles/092904-1.aspx
If you are really interested in ASP.NET Web Forms dynamic controls, I recommend that you study the DotNetNuke CMS Portal. DotNetNuke is one of the best cases using dynamic controls as your core feature to build dynamic portals and pages using ASP.NET Portals. It is free for download in www.dotnetnuke.com.
I hope it helps
Which control is best in terms of performance... multi-view or TabContainer in asp.net ?
According to your description I would probably don't use any of those two controls. I wouldn't go with tabs as you don't really need to be able to switch between them all the time as is seems. The tabs container uses javascript to enable you to change tab on the client side.
About the multiview. I find it bad practice to have that much different logic in the same place and it will probably give you problems later on. In my opinion and experience it's usually better to split that up in different pages and have one for each thing you want to add/modify (you can have the delete at the modify page and/or in the listings). I would recommend to stay away from the multiview control for tasks like this, as I think that having one page to show multiple pages is usually a bad idea.
As far as i know TabContainer isn't a native control in ASP.NET, you could use TabStrip from microsoft.web.ui.webcontrols, but this is limited to Internet Explorer.
So if you have TabContainer from a third party source, use MultiView which is native to asp.net therefore faster. But everything in ASP.NET eventually renders as basic HTML.
I don't know how they render in HTML.
I have an ASP.net webforms app that connects to a web service, All the functionality is on one page that has lots of difference states and I use a multi view to display the correct html depending on the current state.
The problem is the page is huge and unweildly. The code behind isn't so bad but the aspx page is just out of control.
I would like to have a seperate page for each possible state but can't find a good way to move and pass data between pages. Are there any patterns or practices that I can implement that can help with this? And if having a page for each state is not the way to go what else can I do?
I have to stick with the webforms platform :( so i can't move to MVC.
You need to look into Cross Page Posting. This will allow you to postback to a different url and still have access to the previous page's controls. It will make the separation of your different views much easier to manage.
You could create a custom control for each of your states and then programmatically instantiate the appropriate control and populate the properties at runtime.
Use user controls or custom controls to reduce the page weight and improve maintainability of your web forms.
I've always wondered what is the best way to add a new item to html-select in a website.
Yes, this may sound silly but it is a great problem from the usability perspective. I don't want the user to be taken to a new page every time they need to add new item to a html-select.
I like the way Google Reader and Gmail handle this problem in there "add folder" and "add label" functionality. I would like to mimic that but i have no clue how they did that.
I'm using jQuery, so any reference to plugins, code examples or tutorials are welcome.
I would like it to be as modular as possible so i can reuse it anywhere.
I'm using ASP.NET 3.5 web-forms, Microsoft Access 2003, jQuery, IIS 5 and Win XP Professional as web server.
Thanks.
there's a jquery select plugin that might help you with this. I've manipulated select lists client side and had no problem with subsequent form-submits but you'd need to do some experiments w asp.net
The standard technique of doing this is called ajax, which basically means replacing only parts of the page. JQuery ajax and maybe a tutorial should get you going.
A common mistake for this scenario is to add the item on client (using jQuery or plain javascript). It may look that it works until the next post-back. Unfortunately the Asp.NET post-back model does not allow to alter the controls contents on client side only. So basicaly there are two choices:
Use ajax (the simplest would be to
use an UpdatePanel)
Make a normal
postback to add the item (simple and
fast to code, if performance is not
an issue - for intranet applications
for example)