When creating a new GUI, is WPF the preferred choi

Question

Most restrictions and tricks with windows forms are common to most programmers. But since .NET 3.0 there is also WPF available, the Windows Presentation Foundation. It is said that you can make "sexy applications" more easy with it and with .NET 3.5 SP1 it got a good speed boost on execution.

But on the other side a lot of things are working different with WPF. I will not say it is more difficult but you have to learn "everything" from scratch.

My question: Is it worth to spend this extra time when you have to create a new GUI and there is no time pressure for the project?

Answer 1

Scott is complaining about Expression Blend and how it doesn't make sense to him as a developer. My first reaction to Expression Blend was like that. However, now I see it as an invaluable tool, but it really depends on what type of developer you are.

I am user interface developer that has had to perform the Integrator role, and I eventually found Expression Blend invaluable to create styles, and control templates in a WYSIWYG manner. I almost always have Expression Blend and Visual Studio up an running on the same project at the same time.

I also think that playing around in Expression Blend and taking a look at the XAML that gets spit out is an excellent way to learn the WPF API ... much like using the designer in Windows Forms and checking the C# code it spits out is helpful in learning how to use whatever you are designing there.

Expression Blend is helpful. Just give it a try, especially if you are working on the visuals for the application.

Answer 2

I'm seven months into using WPF on what has now become a core system for my customer, and I'd like to share some more thoughts with you about the experience of learning and using WPF as a line of business presentation platform.

In general, the comments I made above still hold... The design time support for WPF isn't here yet. If you're in a big rush to get a rich-client application out of the door, go with Windows Forms. Period. Microsoft aren't in any hurry to discontinue the GDI / Windows Forms platform, so you can count on good support for a fair time into the future.

WPF is not easy to master, but that shouldn't be where you leave your descision about whether or not to invest your time and energy into learning WPF. Despite its present lack of maturity, WPF is built around some useful, modern concepts.

In WPF, for example, your investment in well-written business objects with sound validating logic is a solid investment. Unlike Windows Forms, WPF's data binding is briming with features that allow interface controls to react to invalid user input without writing GUI code to detect those errors. This is valuable.

The styling and templating capabilities in WPF have proven to be valuable too. Despite the common misconception that the only use for styling and templating is to create on-screen eye-candy, the truth is that these features significantly simplify the coding of a user interface which gives rich feedback - like buttons that disable/enable themselves base on the state of the underlying business logic layer, or tooltips which intelligently find their text based on the state of the object under the cursor, etc.

These all add up to incredibly valuable features for "nothing fancy" business applications, simply because they make it easy to keep the interface congruent with the underlying data.

In a nutshell:

• In Windows Forms you design your user interface, then write code to drive that user interface, which generally also includes code to drive your data objects.
• In WPF you invest in the business layer that drives your data objects, then design an interface that listens to your data objects.

It's a seemingly subtle difference, but it makes a huge difference in your ability to re-use code... which begs the question: "Is the Windows Forms vs WPF question actually an investment decision?"

(This seems to have become my favourite thread.)

Answer 3

Are there any compelling reasons to use WPF

Absolutely! WPF is absolutely incredible! It will be a major benefit for practically any project because it has so many features and abilities that Windows Forms lacks.

For business applications the biggest wins will be:

• The fantastic data binding and templating make the biggest difference. Once a decent data model is in place, it only takes a few clicks to create a data template and use Expression Blend to configure exactly how your object will look using drag-and-drop. And binding to things like color or shape is trivial.
• Screen layout is incredibly flexible. Not only can everything in WPF smoothly adjust to container size and shape changes, but items can trivially be enlarged and rotated, and even extend outside their containing frame.
• Ordinary objects can be presented any way you like, can easily have different presentations in different screens, can share presentation, and can adapt their presentation to changes in data values.
• If you need to print, rendering to the printer is trivial. Properly configured, WPF makes Crystal Reports or SQL Server Reporting Services (SSRS) look like a child's toy.
• Your user interface will look and feel much more dynamic, including nice features such as buttons that animate when you pass the mouse over them.

For utilities and games, other advantages come to the forefront:

• You can easily add shapes, lines, and arbitrary drawings to your application without using an external editor. Every component of these can be data-bound and animated, or controlled by code. In Windows Forms you ususally just have to import a bitmap and use it as-is unless you want to go to a lot of work.,
• Animations are cool! Users will be really impressed, as long as you don't overdo it. They can also help people see what is going on and reduce the need for hilighting. For example, when dragging an object you can animate the target to show what will happen if you drop it.
• Colors, gradient fills, brushes, fancy fonts, rotation of any objects, tile brushes, etc. Anything you want graphically is yours for the asking.
• Incredibly customizable. I needed to draw railroad tracks for one application, so I could drop a train on them. A couple of hours later I had railroad tracks I could draw anywhere on the screen using Bézier curves, and they would join and switch automatically.

The bottom line is that any significant-size GUI you could build in Windows Forms can be built in WPF in a third of the effort (or less) and look way, way better.

Does WPF require more resources (RAM in particular)

You do pay a price compared to Windows Forms, but it is a small one.

• RAM can go up or down depending on your implementation. WPF stores its data more efficiently so individual objects are smaller, but there tend to be more objects in WPF than in Windows Forms so this balances out, and either one can come out ahead.
• CPU will go up compared to Windows Forms. In my experience, the actual update of WPF objects onscreen takes about twice as much CPU as normal Windows Forms rendering. If your application spends most of its time updating the screen, WPF may not be for you. But in that case you're probably not using Windows Forms either: Most serious games are written directly to DirectX.
• Disk usage will be slightly less for WPF because it takes so much less code than Windows Forms. The data will be the same size, of course.

One more note about CPU use: Animations and transforms (motion, translation, etc.) is actually more efficient on WPF than in Windows Forms because of its retained mode storage. It is the initial getting of the objects up there that is slower.

Maintenance overhead

WPF is a huge win over Windows Forms when it comes to maintenance. Since everything is done in 1/5 as much code as before, there is 1/5 as much to maintain. Plus all the boilerplate stuff is gone so you can focus on the code that actually does the work.

Benefits of XAML

XAML is the core of WPF. Although WPF can be used without XAML, XAML makes it incredibly easy to use. XAML has HTML's ability to easily specify a user interface, but its built-in tags are much more powerful, and you can easily define your own. (In fact, it is normal to do so).

Some specific advantages of XAML:

• Your entire UI is defined in a text file that is easy to read and manipulate, both for users and tools
• MarkupExtensions allow Bindings to be specified in a clear and simple way
• Type converters allow properties with complex types to be easily specified. For example, you can say Brush="Green" or you can specify a radial gradient brush with three stops.
• You can create your own elements
• You can easily leverage WPF's powerful "attached properties"

Other insights

I dreamed of something like WPF for many years. Many people have implemented portions of this functionality, but to get it all in one place and at such a price ($0) is amazing.

WPF is a huge paradigm shift from Windows Forms and will take some getting used to, but the time spend learning it will pay itself back many-fold.

WPF still has a few warts even five years later, but its power will totally blow you away once you experience it. If someone tries to drag you back to Windows Forms, you'll only go kicking and screaming.

Tips: - Do get a copy of Expression Blend for development - Do edit XAML by hand occasionally - Don't give up when it seems strange at first

Answer 4

I think it is worth learning WPF. Once you are up to speed, design work on your forms is much easier IMHO. I wouldn't worry as much about the 'sexy' stuff. Most of this is just a fad. You can make 'normal' Winforms-style applications very quickly and easy in WPF.

The whole concept lends itself to easier design IMO.

Answer 5

Well, one answer is "when you have to support 1.1 or 2.0", since WPF is part of .NET 3.0. There are known OS limitations for WPF, and there is an obvious skills issue: if you have a team of developers that know winforms, then it may be easier to turn out robust code with winforms. However, if you are writing a lot of UI code it is probably worth beginning to pick up WPF at some point.

WPF also shares a lot in common with Silverlight, so it has transferable benefits.

Answer 6

In DotNetRocks episode 315, Brian Noyes discusses this extensively.