Category Archives: C#

Like WPF – and this MVVM Tutorial

It’s been a while since a last posted, but as with any new love there’s always an intense honeymoon period when you can’t keep your hands off! In my case, it’s WPF – a new toy that is ticking all the right boxes for a GUI nut like me.

The initial buzz soon wore off when I realised that you shouldn’t really try to write WPF apps like you did with Winforms – and then the real fun started as I rapidly scaled the learning curves of styling, databinding, MVVM and MEF.

One resource that really helped switch my brain over from old-school winforms was a video by Jason Dollinger over at Lab49 : http://www.lab49.com/2011/12/06/model-view-viewmodel-tutorial/

The video starts with a “badly written” WPF app (i.e. WPF written as if it was winforms) and then, over the course of 90 minutes, Jason  gently refactors it towards a slick, high-performance MVVM implementation.

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Filed under C#, UI Hints, WPF

Click-through : ToolStrip activation for defocused apps

I’m currently building a multi-process desktop application suite that has a “launch bar” tool to start up instances of all the available widgets. A simple Winforms ToolStrip control seemed the obvious choice for  creating a nice consistent strip of buttons, but I came across the issue that if the launch bar did not have focus, then it took 2 clicks to launch a widget when clicking on a button – one to activate the application and one to click the button.

Having Googled extensively I found that this interaction is not in fact a bug, but actually designed behaviour. I would normally accept this and move on, but I found it particularly inconsistent that the ToolStrip buttons actually illuminate/highlight on mouseover even when the app doesn’t have focus – thus fooling the user into thinking that they need only click once.

Finally,I found a few helpful articles – especially this one by Rick Brewster. The solution lies in overriding the WndProc method for the ToolStrip (or MenuStrip):

protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
if (this.clickThrough &&
m.Msg == NativeConstants.WM_MOUSEACTIVATE &&
m.Result == (IntPtr)NativeConstants.MA_ACTIVATEANDEAT)
{
m.Result = (IntPtr)NativeConstants.MA_ACTIVATE;
}
}

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Filed under C#, UI Hints, Winforms

WANTED: Winforms Recipes

Having spent the best part of 7 years working in C# Winforms, it’s still not 100% clear which is the best way to handle a user’s interaction with a humble TextBox. The .Net framework offers many events that can be used to manage behaviour, but I’ve never seen any documentation stating the “Best way” or the “Right way” to do it.

Take for example a simple interaction. I have a simple textbox, and would like to perform an action once the user has typed the value and hit [Enter]. Which event should I use ? Validated, Validating, KeyPress, Leave ?

I know it all depends upon the exact scenario, but hey, Microsoft, throw us a bone!

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Filed under C#, UI Hints, Winforms