In Windows Forms, it was useful at times to have one window that inherited from another window. But in WPF, this is not allowed. Why is there no visual inheritance for WPF windows?
The reason WPF does not support visual inheritance is due to the fact that the form design is achieved via markup (.xaml) as opposed to winforms which use code-behind to produce the layout. Code-behind is extensible and markup is not. The same goes for web forms. Master pages in asp.net offer a quasi visual inheritance. So it is a trade off, markup offers the benefit of a clear separation of layout and data whereas code-behind offer visual extensibility. It is a bit of a shame since visual extensibility works so well in creating consistency in the GUI as well as very rapid development. Well, it seems flare is more in demand than functionality. WPF is just ok...
WPF is deliberately very, very different from Windows Forms. The composability model is not based on Windows, but on classes like Dependency Object, Visual, UIElement. You can also dramatically modify the behavior of existing things using control templates, styles, data binding and other techniques.
I encourage you to experiment! WPF is very easy to prototype with
In WPF, a large effort was made to separate visual from logical. Because of this, there is a LARGE amount of freedom to make the UI look however you want. All of the controls, including windows, are "lookless". You can provide your own look via templates and styles. A default visual style has been provided that makes everything look like you would expect, but you don't have to use it.
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I'm familiar with WPF technology, specifically MVVM methodology. Recently I began to program in Winforms, and I was wondering- Does using data-binding in winforms (combined with INotiify...) is considered the best practice, or is it an overkill?
Some people say that data-binding is a real pain in the ass in winforms, is that right?
And just to make it clear: I'm not talking about full MVVM implementation in winforms- simply binding data to controls (text boxes and such, not buttons).
Data binding in Windows Forms works very differently than WPF - and is (IMO) a bit more of a pain. The main issues are there are more restrictions on the binding source, and there isn't a clean way to handle things like IValueConverter, so there is typically a lot of extra work involved in getting anything but very simply binding to work cleanly.
Details on how to use data binding in Windows Forms are described on MSDN in Windows Forms Data Binding.
Is there a way to download more controls or anything, because I have seen a few things in other programs I don't think I've seen in the toolbox. Can you download new ones, or did the company somehow custom make a control? If it was custom made, are there any tutorials I can take a look at that tell how to make your own?
Some companies make third party controls for Winforms - Telerik is one I know of.
Personally, I prefer to make my own controls based on the existing WinForms ones, as I have more control over them - this prevents my products from having bugs which just can't be fixed. I can also tweak the controls to do exactly what I need, rather than choosing a closest match. Building custom controls is relatively easy if you have the experience.
There is a basic tutorial on CodeProject which shows how to create a fancy Button. After that you should be able to figure out how to customize more complex controls.
Side-note:
While it's reasonably easy to develop custom controls in WinForms if you have the time to practice, WPF is a much better framework for building custom controls. WPF controls are designed specifically for customization, so there is a lot more flexibility.
I've been doing WPF applications with the MVVM pattern using Visual Studio, coding C# and XAML mostly by hand.
Now I've gotten up to speed with Expression Blend so that I can click together WPF applications quickly just using the GUI, which is very nice, much more control of the layout than fiddling around with all the XAML elements 80% of your time.
But it seems that my applications in Expression Blend are simpler and necessarily coupled, using events that are handled in the code behind, etc.
I find it hard to imagine how I would go from this simpler approach of Expression Blend to a decoupled MVVM application with Views, ViewModels, routed events and commands, etc. other than to just take my whole project into Visual Studio and rearrange it to the point that I couldn't really edit it visually anymore in Blend, but would be back to using Blend to create little pieces of XAML that I paste into Visual Studio.
For those of you who are working with more complex applications with Expression Blend, what are your strategies for keeping your projects decoupled in an MVVM way, yet at the same time structured "in the Expression Blend way" (where you can still see and edit whole parts of your application in a way that makes sense visually) so that you can continue to edit them in the Blend GUI as they scale?
I've been using Blend first and foremost as a rapid-prototyping tool. For this purpose, I really like it. In particular, I find it very helpful when I'm not sure how to set things up to get the layout/behavior that I want.
I rarely edit my main project files directly in Blend. I find it creates markup that is unnecessarily complex or verbose. Also, as I become more familiar with WPF/XAML, I find myself using Blend less and less.
I have been using Blend for the UI of my projects since version 1. Being that my goal is to fully integrate the designer to the project, I have plowed through whatever gets in the way of this goal. While not being aware of MVVM for some time now, I naturally arrived at the same conclusion, and have been making ViewModels without knowing there was a pattern for them. Now with the help of others that are working towards MVVM, it's getting better all the time. I have now developed 3 applications with rich UI and functionality where all the UI was done in Blend.
Read Josh Smith's MSDN article, look at Jason Dolinger's work, and Karl Shifflett's work to mention just a few.
Look closely at using ICommand, INotifyPropertyChanged, the ObservableCollections.
Also, look for how you can manipulate controls from your ViewModel. As an example, there is ICollectionView. Assume that you have a list of animals, and you have a set of types that you want to filter them by (birds, mammals, etc.)
By using ICommand and ICollectionView, you could expose enough control where a designer could construct a listbox to show the animals, and a menu to show the filter list. There is enough functionality in ICollectionView to know what the current selection is, and if you had ICommand-based commands for "SortByBird", "SortByMammal", etc then when the designer made the menu, it (assuming the window's context was your ViewModel for this window) would supply the designer with the proper options to bind to.
I am currently working with another team at my company explaining how my projects have been set up, and they are responding positively to the new role of the designer using Blend.
I have not been able to successfully use Blend end to end for that.
I find in the general case, it's faster to edit xaml by hand in VS (exception would include anything with non-standard brushes for example). Blend is very click-happy, and it's not really fast to top it off.
Another area where Blend is really useful is creating styles/templates from existing controls.
Other than that, I'm not sold yet. Its capabilities drop when using code-instantiated datacontexts so it's no help there, and it tends to generate useless markup, static sizes and such, which I really don't like.
Blend is great for giving you an idea about how things can be done, but the xaml it makes is terrible and tightly coupled. As you learn the xaml side of things better you'll find it's much faster to just write the xaml than use Blend. Until you get to that point you can make your changes in Blend but then you should refactor the xaml it creates to make it less tightly coupled and take out the extraneous UI elements.
I'm a little late to this party, but hope that someone can still respond. I've yet to find a search result that outlines the process for drawing a line between the designer and programmer. The first part of it is MVVM so there isn't any coupling between the GUI and the underlying "business logic", and I'm working hard on learning that right now. The other part that I haven't seen anyone write about is, how do you actually go about designing a project in Blend so that the developer can basically give you a GUI DLL of sorts, and then your application's GUI magically changes?
Here's what I'm looking for -- the developer writes his code as usual, and also writes a very basic GUI that proves everything works as expected. Meanwhile, the designer is creating his cool little GUI with all of the usability features people have come to expect. Now, the developer can run his application with his GUI, but then can also switch to the designer's GUI on the fly.
I guess if it can't be done on the fly, does that mean in the ideal case that the developer would have his VS solution include the XAML from the Blend solution? Then in App.xaml just reference a different start file?
I am very confused about WPF and Windows Forms. What is the usage of WPF over Windows Forms?
What is the usage of WPF?
WPF is a new platform for developing applications for Windows (and for browsers). WPF is not necessarily there to replace Windows Forms. With WPF, it is easier to add 3D, video, and animations to your application. Because it is XAML based, it is also easy to bind to XML data, for example, data from a webservice, and dynamically load it as content.
WPF also, in my opinion, better seperates the UI programming from the business logic. It is easier to have an advanced WPF designer build your UI with a tool like Expression Blend, and yourself as a programmer, focus more on the back-end. In that way, it is more like having an HTML and CSS frontender creating a slick design for your site, while you work on the back-end.
Windows Forms has (as for now) more third-party controls available though, and if you don't really have a need for the stuff that WPF brings, then you certainly don't have to switch to WPF.
Have you seen WPF or WinForms, choose wisely ?
In short, WPF is the next UI platform for Microsoft Windows. It learns a lot of lessons from previous technologies, but the risk is immaturity of tooling and third-party components.
One benefit is the separation of concerns. You can build your application without worrying too much about UI stuff like layout, colours, fonts, etc. Then you can pass it to a designer who can make it look amazing (hopefully) without needing to understand code (using Blend or some other tool).
From a purely pragmatic point of view, my choice of which framework to employ is often down to which third-party controls I need to use (although you can use a WPF control in a WinForms app, for example - using hosting controls).
One more thing I like about WPF is that the core graphics processing has been shifted from GDI+ to DirectX. That makes a huge performance benefit when you are working on 3D or heavy grid/time series plotters as it tries to consume your GPU (graphical) resources rather than CPU.
I just installed visio, and the installer almost seemed like it was built in flash.
The buttons kinda glowed when I hovered over them, and when I clicked on 'continue' the form phased out in a cool way.
I'm assuming it was built in WPF.
Anyhow, so are WPF more flash-like (visually speaking).
Do they have new properties where you can make forms phase out nicely/smoothly compared to winforms?
Disclaimer: I work for Microsoft. However, I don't work on Visio, WPF, CLR or Silverlight team. So, the following is my personal take on these technologies. If you want to quote me, don't do it implying it's the official Microsoft position. :-))
Update: Anything I say below about Flash/Flex/AIR might be wrong, as I have not worked with these technologies and what I know about them is based on what I read on the intertubes. :-) If you notice anything wrong, just shout in the comment and I'll correct it.
To the best of my knowledge, the Visio installer is not built with WPF. It's all unmanaged code; it's just people took a lot of care to make it really polished.
WPF is the new UI platform for building standalone applications for the Windows OS. It supports a declarative UI language - XAML, and related CLR types to program against. WPF is a different platform than WinForms, although it is possible to build applications that mix UI built with both. WPF supports a lot of things that WinForms does not, like bitmap effects, animations, control styling and so on and exposes them both in XAML or through code. Also, WPF relies heavily on vector graphics, as opposed to the pixel graphics in WinForms. In short, WPF is quite powerfull and allows building very snazzy UI. (Don't take my word for it, though, as I am biased; go check around for what people are saying about it or buiding with it. :-))
WPF and WinForms do not compete with Flash/Flex. WPF and WinForms are both UI frameworks for building standalone client applications. As far as I know, Flash/Flex are frameworks for building rich internet applications - RIA (though lately people started interpreting this abbreviation as rich interactive applications).
Adobe did come up with AIR about half a year (or maybe a year) ago, which allows building standalone client applications, so you could say that Adobe is trying to position Flash/Flex/AIR to compete with WPF. Of course, that's my take on it and I doubt Adobe's official positiong is anything like that.
If you want to compare particular MS technnologies with Flash/Flex, take a look at Silverlight - it's the MS RIA platform.
Silverlight is related to WPF in the sense that they share XAML and the corresponding CLR types. Silverlight supports only a subset of what WPF offers, though, as it is not targeting Windows OS only and thus is limited by the fact that it has to be portable.
Quick update to reflect the changes in the year since I've written the answer :-)
With Silverlight 3 shipped, SL and WPF are getting even closer and sharing bigger set of supported features. In addition, most of the new XAML controls are built for platform at the same time. Thus, SL/WPF are getting to a point of singularity...
Also, SL 3 supports out-of-browser applications. In that sense, SL is not only starting to compete with Flash/Flex, but it is also encroaching on AIR's turf.
And no, I still don't work on the WPF or Silverlight team. :-)
WPF is being used as a replacement for WinForms, and as a competitor to Flash in the form of Silverlight. WPF consists of an entirely new object model that sits on top of DirectX (at least the desktop version). You can create WPF windows, controls, etc, entirely using C# or another .Net language just like you can render WinForms. However, Microsoft has also created a markup language called XAML (eXensible Application Markup Language). Nodes in an XAML document (XML) map to objects in a similar fashion to the way ASP.Net maps to web controls. XAML typically exists in a .Net project alongside a code-behind style C# file (or VB.Net or whatever). The C# file interacts with the objects generated by the XAML. This is fairly consistent with the "graphics via markup, logic via code" model that Microsoft and others are pushing.
One of the overlooked features when discussing WPF is the completely awesome data-binding that Microsoft wrote for WPF. The new data binding framework is a quantum leap beyond Windows Forms 2.0 data-binding. Microsoft added a couple of new interfaces that make it much easier to make an object or collection emit data-biding events properly. They also provided a very rich set of data-binding classes. You can bind anything to just about anything else. You can bind one-way data to control, control to data, two-way control to data and back, control to control, etc.
Back on the graphics side of the house, WPF makes it fairly easy to make an existing control look like anything. WP lets you compose your own template for what a class of buttons should look like, or one button, or all buttons. Or radio buttons. Or labels. You get my drift. Imagine if CSS included the ability to define what an input button would look like using other HTML controls.
They also provide a number of layout controls. You can continue to use exact positioning like in WinForms, or you can leverage of variety of techniques to make your window act more like a web page that grows and shrinks with resizing, etc.
The downsides: It is too easy to create spectacular effects that crawl on slower machines. Some of the graphics do not take advantage of hardware of graphics cards, though Microsoft has incrementally improved support for this. I believe when 3.0 first came out drop shadows were rendered purely using software. I think 3.5 or 3.5 SP1 changed it so that WPF would utilize graphics hardware for the task. Microsoft has said they will continue to enhance WPF in this fashion.
WPF is .Net 3.0 and above, which runs on XP SP2, Vista, and Servers 03 & 08. So don't plan on deploying WPF to a customer with Win2k desktops.
Summary: If you are doing desktop programming in .Net, you should be doing it in WPF unless you are targeting Win2k. You can avoid the downsides of WPF, and there are many upsides. Microsoft will probably throw away WinForms in some future release, or at very least you will stop seeing new features, etc.
As far as Silverlight goes, the betas for SL 2.0 look good. I think that Silverlight will require some wide-spread adoption. Microsoft has already tried to get this going. The NBC Olypmics site used Silverlight, and Major League Baseball uses it for its MLB.tv product. As soon as Silverlight gets a good install base I think you will see the Microsoft side of the development world starting swinging away from Flash and to Silverlight.
Edit after using Silverlight 3 and MVVM:
I have moved away from WPF and am doing a lot of Silverlight 3 development. But I think my comments here will still apply to the WPF developer.
I have been using the MVVM pattern in my app (think MVC with a twist). The Microsoft Patterns and Practices team has released a set of libraries known as Prism that supports various aspects of MVVM. There are WPF and Silverlight versions. Take a look at MVVM and Prism if you are going to be doing WPF or Silverlight development.
You can do a lot of flash w/ Winforms, or with custom components. But if you want out-of-the-box bang-whizz availability, WPF is the way to go.
Yeah, I think the intention is to be flash-like, it seems to me that MS has set its sights on taking down Adobe.
The way I see it: WPF is to Flash as WinForms is to Flex. WPF has more emphasis on vectors and states than on programming.