If we want to convert a Page to user control then we should also do the following:
“If you aren’t using the code-behind model, make sure you still include a class name in the Control directive by supplying the ClassName attribute. This way, the web page that consumes the control can be strongly typed, which allows it to access properties and methods you’ve added to the control..”
I’m not sure I understand the above quote:
Namely, if we don’t use code behind class, then ascx class will derive directly from UserControl class!
Thus if we don’t use code behind class, then there won’t be any methods or properties added to a control, so why would web page have problems accessing any of user control’s properties and methods? So why would we need to include a class name in Control directive?
thanx
I think I should clarify how the compilation model works. First of all, you can write everything (including C# code) in a single .ascx file and inherit from whatever class you want to (that ultimately inherits from UserControl) by specifying Inherits attribute (or you might want to omit it) and without a ClassName attribute. If you do this, you can still access the properties from the .aspx file that uses this control. The thing is, you can't use the class in the codebehind file of .aspx page (if it has one) directly. By specifying the ClassName, if you are using the Website project model of Visual Studio, you can access it from the .aspx.cs file too. Note that this would not work in Web application project model as every .cs file will be compiled ahead of the time (prior to the .ascx file). In that case, even ClassName attribute wouldn't help much.
In any case, strictly none of the attributes are necessary. You can always use the properties defined anywhere in .ascx or .ascx.cs file included in a page in the .aspx file (but not always .aspx.cs file).
Edit to address the update to the question:
A) From your source code, it seems you are using the Website model here. Note that I mentioned you cannot use the class directly. I agree this statement might have been a little misleading. What I wanted to note is that without a ClassName, ASP.NET will choose a name for your user control class but that name is not guaranteed. While you can use the generated name, it's not recommended at all. You should treat it pretty much like an anonymous type where you can use an instance but cannot mention a name. In your example, you are basically referencing an instance (which is constructed on the .aspx markup), not the class, which is OK.
B) What you are saying is correct. Whatever you declare in ascx.cs in a Web application will be visible to .aspx.cs and .aspx. What I was talking about is properties that you declare in .ascx in a <script runat="server"> tag. Those will not be visible to .aspx.cs since it's compiled beforehand.
C) ASP.NET will generate the class defined by the ClassName attribute in the ASP namespace. You should use ASP.Some_Name instead. There is one thing I forgot to mention: in this case, you should somehow reference the .ascx in the .aspx markup; either with a Reference directive (<%# Reference Control="MyControl.ascx" %>) directive or with a Register directive (<%# Register TagPrefix="abc" TagName="xyz" Src="MyControl.ascx" %>). This will ensure that the ASP.NET build engine puts the generated .ascx class in the same assembly as .aspx page.
if we don’t use code behind class,
then there won’t be any methods or
properties added to a control, so why
would web page have problems accessing
any of user control’s properties and
methods? So why would we need to
include a class name in Control
directive
You can embed any code behind code in your .ascx/.aspx file, in new asp.net mvc model, there won't be any code behind by default. I think code behind is optional, it's just a nice way to separate one class into two pieces. Partial class is used in code behind.
Even if you don't use code behind class, you can still inherited properties from base control. Then by declaring a class, you will be able to access those properties too.
Related
I am using the AJAX Control Toolkit in an ASP.NET web site. I would like to change the names used to refer to the toolkit's classes according to my project's conventions, both in the Controls pane and in the markup itself.
Maybe something like:
<%# Register ?something? TagPrefix="MyControls" %>
For instance, I'd like to rename the AutoCompleteExtender class as SelectTextBox in the code, so I can use it like this:
<MyControls:SelectTextBox ID="sss" runat="server" ColumnList="aaa"
ColumnType="0" ColumnWidth="300" DataField="aaa"
DetailedSearch="1" FillQuery="SELECT XXX" ValueField="EmployeeID" />
Is it at all possible?
I was curious about your question (that's why I edited it in the first place), so I looked around, and I'm afraid I'm not coming back with good news.
Although facilities like type aliases do exist in C#, they will only affect the modules where the using directives are in effect, and will not propagate to the ASP.NET markup AFAICT (let alone to the Controls pane).
Barring extending Visual Studio itself, your best bet may actually be to derive your own classes from the ones in the toolkit, use these in your code, and create a custom Controls pane section out of them. That way, naming will be consistent everywhere in your environment.
On a more positive note, maybe someday you will want your SelectTextBox control to do something more than a plain AutoCompleteExtender, and then you will have the derived class already there waiting for you.
I have an issue where I have two pages that deal with very similar things and as such quite a few of their methods and aspx server controls have identical method names and variables. In short, it's pretty obvious that the code was copy/pasted and the innards were merely altered. I have a pending request that the two pages be merged so I've explored a number of options as to how I should best merge them.
First I thought that perhaps I could put one of the pages in a masterpage that will allow for a content place holder wherein I'd then put the code/controls, but it looked to be a bad idea once I started to make plans. For one the similar names would probably still be a problem and second it seems a rather clunky way to merge two pages together.
I've considered renaming all the methods and controls but on the other hand it's going to take a lot of time picking over the code and the controls to rename them all. My worry is that if I try to change the problematic method names, controls, IDs, I'll introduce a lot of bugs in the code.
Is there a better way to view two pages in one webpage?
You can do so with iFrames. But I think the website gets better maintaining with .net controls (.ascx files), and then calling them in a new page
That thing is called user control.
UserControl class
read this official tutorial
I think there can be 3 options that will work for you:
1. Put all common stuff in a user control and use it in both pages. This is the most straight forward solution and this is the main reason user controls exist - reuse of both UI and code behind. This is most likely the best option.
2. Have a utility class that will contain all common methods. The disadvantage of this solution is that you will only share code, not UI.
3. You can have a BasePage that inherits from Page, and have both pages inherit from BasePage. Again, you will shared only the code, not the UI. This is usually a good solution when you want to add some functionality for all your web pages.
If it is for ASP.Net Web Forms have you checked out Nested Master Pages, not merely a single MastPage?
If you have a common Theme or layout this goes in the Base MasterPage, your nested MasterPage then exposes common UI controls, Events Handlers etc that are common between the next group of Pages (the layer you referred to), your final ASPX Page then exposes the individual page functionality that is different between the ASPX Pages, UI controls, Events etc for each unique page.
By using the # MasterType page declaration you ASPX Page has a strongly typed reference to one or all MasterPages which would allow the ASPX page to easily access methods and properties of the common MasterPage.
Is there a c# command to include another web page - the equivelant of the php require?
I know how to do server side includes but was looking for something code based.
Thanks
Thanks for the answers all. I think I might need to explain further. I have several sub-pages that I will be loading during the use of the site using an xmlhttp request. Initially however, I need to load the starting sub-page before the user has interacted with the site. I could do this with js, but that would require more overhead in server calls from the client for the initial load. I already use master pages, but this is a little different. Since this is done serverside initally but must remain able to be refreshed clientside, I don't think I can make these pages into controls can I? I am pretty new to .Net so I may be making my life harder than I need to.
I think what you may be looking for are MasterPages and UserControls. A MasterPage allows you to define a basic template that is "filled in" by the implementing pages by having the implementing page add it's own content to the ContentPlaceHolders defined on the MasterPage. A UserControl is a re-usable piece of markup and associated code that you can reference from your mark up or add dynamically to the page being rendered in codebehind.
The way ASP.NET is structured, you shouldn't really need to do this. Code is compiled, so all of your classes and functions should be accessible simply by referencing the relevant assembly or namespace, without having to include individual code files.
You might be looking for user controls, which allow you to create fragments of markup with their corresponding code behind, and then reference these in your page.
With ASP.NET MVC it looks like this:
<% Html.RenderPartial("LogOnUserControl"); %>
This way you can put another UserControl on your page.
you can use include in asp.net like php include from below mentioned code
<!--#include file="include/leftmenuscript.inc"-->
You can also use a master page, as someone stated below, which flushes out your basic layout and lets you define content place holders, which other pages can implement and fill in the content. Master pages are a popular approach for defining page elements that are consistent across all pages, like your nav there (also things like headers, footers, common scripts, CSS, etc.).
I'm using .net 2.0. I'd like to place one of my C# methods in an inline server script block inside my ascx file because I need to update it a lot while designing. This way I don't have to compile my large project everytime.
I would like to call the method from inside my code behind file. I use to do this by inserting a virtual stub method in the codebehind file and overriding it in the ascx file. Now, since I've started using partial classes, I was expecting to be able to just call the method directly. Is this not possible?
Thanks
Unfortunately, I don't think this is possible. At design time, the partial class (*.designer.cs) mainly contains just your controls. The class that actually contains code from the script block is also generated by ASP.NET but it inherits from your main class.
See http://msdn.microsoft.com/en-us/library/ms178138.aspx for more info.
I don't understand your motive... Isn't it just as easy to modify a page's codebehind as it is the .ascx file? Either way ASP.NET is going to either dynamically compile them when the file gets accessed or force your to rebuild, depending on the type of project.
I have created a webpart in c# for sharepoint.
its basically a form with text boxes, literals, validators and buttons.
im not sure how to render this form to make it look pretty.
The layout etc is being done entirely within this c# class.
At the moment to get started im just overrinding CreateChildControls() method
and adding each form control using something like: this.Controls.Add(submitButton);
any ideas on how best to layout this form?
Thanks.
When creating custom webparts I also prefer to implement them by overriding the CreateChildControls() and Render() methods. In the Render() method I have full control of the html output and I can render my inner controls by calling this.someInnerControl.RenderControl(writer).
Having full control of the html output also makes it easy to style the html using CSS. As other people suggests, use an external CSS file and apply the styes to the class attribute on html elements or CssClass property on ASP.NET web control.
When I implement webparts, that does not require special branding, I prefer to reuse the CSS classes defined by SharePoint. This will ensure that my webpart is visually similar to the webpart provided by SharePoint and that I keep a consistent look and feel.
When using the SharePoint defined CSS styles, you should be aware of your html output. Some of the CSS classes requires a specific html structure to properly render. You can always use the browsers "View Source" to check the html of the SharePoint element you are trying to imitate.
I would recommend grabbing the source from an existing sharepoint page and using the styles defined by sharepoint. This link to the styles in 2003 is old, but still a good guide to get started. Most of the CSS class names haven't changed.
In my web parts I include css files in the solution and inject them in the page using something like:
this.Page.Header.RegisterCss("/_layouts/path/to/css/file.css", false);
You can override the RenderContents(...) method to manually render the HTML in anyway you want to. This includes adding any css includes, scripting includes, etc. that you want/use.
You can render your child controls to strings and then output them as well, but you probably should NOT call the base.RenderContents(...) method.
Just make sure you don't forget to render your child controls.
If it's important for you to see as you design, use the SmartPart which embeds a user control in a web part. (In case you didn't know, user controls can be designed using the tools within Visual Studio.)
If you prefer to hand-code, then you're on the right track. Simply create and set initial properties for your controls within the CreateChildControls() method and use this.Controls.Add() as you have been.
In both cases, where possible use the CssClass property so you can tinker with the look and feel in a CSS file without having to recompile. You could hard-code the CSS class names but it would be better to use the web part properties or an external config source to store these. Have a reference to the CSS file in your master page or inject it into the page using the other techniques mentioned in this answer.
The MSDN articles Web Parts in Windows SharePoint Services or Creating a Basic Web Part might also help.