WPF Blend tools vs hand-coded XAML for interface controls

Question

Hi this might seem like a dumb question, but I was looking for a little feedback. I am designer working with a development team on a WPF application. We installed Expression Blend 4. I new to WPF/Silverlight, but I have jumped right in and I think it's great.

However, I did notice that xaml code that can get generated when using Expression Blend can sometimes be overly obnoxious. For example, I created a Control Template for a button with Blend and the markup was like 100 lines of code. Then I created my own control template that was only 20 lines or so and it did exactly the same thing. I did the same thing for a listview and wow, that amount of code that was generated for a ListView template was RIDICULOUS. So again, I created my own styles and templates and the result was A LOT less xaml code.

The app we are creating is going to be pretty big I guess, so my question is, is it that much of a concern for performance if I were to simply create all design/interface elements using blend GUI, even though the generated code can be a lot more extensive? I can see how using Blend tools for design can make things a lot easier, but just like when designing websites, I have never used design view in Dreamweaver because the code that gets generated is pure crap.

Any insight would be greatly appreciated.

Thanks a lot

Answer 1

Personally i would only use any designer for drafting and real-time display of the visual representation of my hand-written code. The generated code may not be horrible but once you need to go into it to do something manually you will have a hard time finding everything you need if you did not write it yourself. Also Blend slices things up quite a lot (create resource & reference it) while i like to nest things in place if they are only used once (i do not know if the code generator could be adjusted in that regard).

It should not be performace concern that the templates are big, if you just copy the default ones used they are quite huge themselves and it's not really an issue.

Answer 2

I'm guessing the control template you generated for the button didn't actually do the exact same thing as the default one which you copied in Blend. You may think it did, but I'm guessing it was missing something. For example, did your template handle all 9 visual states that are used by a button? If you had only 20 lines of XAML, probably not. And yes, the ListView control template is quite large because it's quite a complicated control under the covers.

In general, I wouldn't worry about generating large control templates. It's going to happen. The runtime handles this quite well, in general. Unlike Dreamweaver, Blend generally gives you pretty good code. Performance only becomes an issue if you misuse resource dictionaries by doing something ill-advised such as setting the build action to embedded resource in visual studio. (I believe this creates a loose XAML file which must be parsed and compiled at runtime instead of compile time.)

The key to maintaining your sanity is organization. Just like with a website, you need to come up with an organization scheme for how you're going to store your control templates.