Assuming you already installed the Windows 10 IoT in your Pi 3 and that it is currently up and connected to the network, you can open the Windows 10 IoT Core Dashboard, go to the “My Devices” tab and find your device listed there.
If you now click the “Open in Device Portal” option, the browser will launch, ask you to login with your credentials, and then show you the “Home” page of the Device Portal.
On the bottom you will find the “Display Orientation” option:
Given my touch screen is placed upside down, I changed this setting to “Landscape (Flipped)”, and after rebooting the device I noticed that it flipped the touch screen display as requested, but it didn’t also flip the touch targets (so you’ll need to mentally rotate every point you touch on the screen to make it do what it is supposed to do)!
Under the hood, what this setting is doing is adding display_rotation=2 to the Raspberry Pi “config.txt” file, but that’s not the proper way of doing this for the touch screen!
Like it or not, the so called “Hamburger” design pattern has made its way to pretty much every platform, including the Windows Universal Apps!
Most Windows 10 native apps already show this new pattern, even a classic like the Calculator app!
However, for reasons unknown, Microsoft didn’t provide any Hamburger related control on the SDK base controls… frankly, this move brings back to memory when Windows Phone 7 SDK was launched without the Panorama and Pivot controls, the foundation of the whole “Metro” design guidelines!
The only alternative I’ve found is to use the Template 10, a “set of Visual Studio project templates”!
However, I’ve found that Template 10 version for Hamburger adds a bit of too much “fat” for my own taste, hence why I’ve been working on an alternative for the past last few weeks!
Introducing the Cimbalino Toolkit Controls
Starting with version 2.2.0 (currently still in beta 1), the Cimbalino Toolkit will feature a new package called Cimbalino.Toolkit.Control, and as the name suggests, it’s a control library for app developers.
Currently, the package features 3 controls:
Starting from the top, the HamburgerFrame control is a full replacement for the native Frame root control used in the app.xaml.cs file.
The control provides 3 content containers represented by the Header, SubHeader, and Pane properties, and on the center, it will show the navigated content:
Obviously, you can specify content for this containers however you would like, or just leave them blank!
The Header allows content to be presented above the Pane, so it will never be hidden by it:
The SubHeader allows content to be presented on the right side of the Pane. This means that if the pane is in one of the “overflow” modes it will show on top of this container, hiding the content behind it:
The control also provides background properties for all these containers (HeaderBackground, SubHeaderBackground, and PaneBackground).
To make the life easier of developers, I’ve “borrowed” the VisualStateNarrowMinWidth, VisualStateNormalMinWidth, and VisualStateWideMinWidth properties from Template 10, which allow to specify the break points where the pane state and location will readjust. If you don’t want to use these, you can always do it manually with the exposed pane related properties (IsPaneOpen, DisplayMode, OpenPaneLength, CompactPaneLength, …).
The HamburgerTitleBar control provides a basic Hamburger button on the left side (can be hidden with the MenuButtonVisibility property), and a Title property.
This is a quite rudimentar and easy to use control, yet developers might want to just go ahead and create their own version of this control and place it on their apps!
Finally, the HamburgerMenuButton is the button you’ll be using in the pane to indicate the available menu options!
This control shows a left-side icon and an optional label (through the Icon and Content properties):
The regular approach here will be to just place all the HamburgerMenuButton controls inside a vertical StackPanel, but one can also stack them horizontally, and in this case, we would only show the icon and hide the label (using the provided LabelVisibility property).
The NavigationSourcePageType property allow developers to specify the destination page type for navigation purposes. If the property is set, the button will automatically highlight anytime the page is the frame current navigation content.
Congratulation: your app now has a universal Hamburger menu with a nice title bar! :)
Next steps might be to create a separate user control to hold the HamburgerTitleBar, which will then allow you to bind the Title property to view model (making it easier to update on a page by page basis).
To make things easier, I’ve provided the source code for a simple app using these controls!
Update: Though the information and concerns in this blog post are still very true, I’ve actually had a change of heart and I’m now advocating to Start Strong-Naming your Assemblies!!
For far to long, Strong-Named Assemblies have been a huge rock in the shoe of 3rd party library developers, but people: it’s 2016, so why are you still using it?
How it all started…
The year was 2002 (or so I believe!), Microsoft had just released the .NET Framework, and one of the main enterprise focused features was the ability to sign an assembly with a strong-name.
Back then, Strong-Named Assemblies had some great advantages, as indicated in this MSDN article:
You want to enable your assemblies to be referenced by strong-named assemblies, or you want to give friend access to your assemblies from other strong-named assemblies.
An app needs access to different versions of the same assembly. This means you need different versions of an assembly to load side by side in the same app domain without conflict. For example, if different extensions of an API exist in assemblies that have the same simple name, strong-naming provides a unique identity for each version of the assembly.
You do not want to negatively affect performance of apps using your assembly, so you want the assembly to be domain neutral. This requires strong-naming because a domain-neutral assembly must be installed in the global assembly cache.
When you want to centralize servicing for your app by applying publisher policy, which means the assembly must be installed in the global assembly cache.
So strong-named assemblies are uniquely identified, which is a good thing, until it starts to work against you…
Let’s look at a real example: a few years back, JSON.net was actually a strongly-signed assembly. Now let’s assume we have a project that depends on “LibraryA” and “LibraryB”, and each of these require a different version of JSON.net.
If you build the project as it currently is, there will be a conflict as you can only have a single version of JSON.net on the output folder, but the libraries require different versions…
To fix this issue, .NET provided a mechanism called Assembly Binding Redirection to ensure that only one specific assembly would be used, regardless of the required version.
In comes Silverlight and Windows Phone
Unfortunately, neither Silverlight nor Windows Phone support Assembly Binding Redirection… and that is where the true problems started.
Others, followed the advice of the MSDN article I pointed above:
If you are an open-source developer and you want the identity benefits of a strong-named assembly, consider checking in the private key associated with an assembly into your source control system.
Obviously, for this to work you would have to build your own versions of your project dependencies… and let’s be honest here: that will eventually be more of a problem that a solution.
A few years ago, I personally felt this pain while developing a Windows Phone app, and so I went to the Windows Phone Developers UserVoice website and requested the support for Assembly Binding Redirection on Windows Phone… almost a year after the request, I got an update indicating it was “on the backlog”, and seems it has stayed like that till now…
If it is such a bad thing, why are people still doing it?
Developers seem to have the wrong notion that they should strong-name their assemblies as a security feature, but this could not be further away from the truth!
Granted, that does provide a basic insurance that an assembly hasn’t been tampered/altered, but in any case one can always use binding redirection (when available) to bypass the whole thing, so that is just a lame excuse to not buy a proper Code Signing Certificate and apply Authenticode to the assembly (which will prevent tampering AND impersonation, the right way!).
What about the Universal Windows Platform?
Unfortunately, as far as I know there is no support for Assembly Binding Redirection in UWP…
Assuming we are on a background thread when the DoStuff() method is invoked, we will retrieve a CoreDispatcher instance from the CoreWindow.CoreDispatcher property, call and await for the execution of dispatcher.RunAsync() method, which in turn will invoke the UpdateUI() method on the main thread, and then code execution will continue in the background thread by invoking the DoOtherStuff() method.
As it is right now, we know that DoOtherStuff will only execute after the UpdateUI() method finishes, but now let’s assume that we replace the UpdateUI() synchronous method with an asynchronous version of it, called UpdateUIAsync():
var dispatcher = CoreApplication.MainView.CoreWindow.Dispatcher;
In this new version of the code, you’ll notice that the DoOtherStuff() method will eventually run before the UpdateUIAsync() has finished, which might not be what you intended to in the first place when you await’ed for the dispatcher.RunAsync() method!
In this version of the code, once the execution returns from await’ing the dispatcher.RunAsync() call, the background thread will carry on execution, but will then await for the taskCompletionSource.Task to finish, which will only happen after the taskCompletionSource.SetResult(true) call that we make in the main thread!
As you can see above, we create a new MainViewModel instance, set it as the page DataContext property, and then we have the three click event handlers, one for each of the buttons on the view.
We’ve also added a MainPage.ViewModel property to expose the current MainViewModel instance to the compiled bindings (we can’t use the DataContext property as its type is object and compiled bindings require strong-typed properties to work).
This is what you’ll get if you run the app and tap the buttons in succession:
As you can see, the 2nd TextBlock (the one using compiled bindings) never gets the text cleared when we tap the “Destroy CurrentTimeViewModel” button!
The expected behavior is the one shown in the 1st TextBlock: if the binding value is null or unavailable, the TextBlock.Text property will set to the Binding.FallbackValue (which is null by default).
So after checking the documentation for compiled bindings, one can say without that compiled bindings are ignoring the fallback value when its value is null, and that is quite a nasty bug in the compiled bindings!
This bug has already been reported to Microsoft but as we don’t know when it will get fixed, all we can do right now is be aware of the whole issue and make sure to test our apps thoroughly to ensure we don’t end up with these problems after migrating to compiled bindings!
I built a small test app and after a couple of minutes debugging it I noticed a MissingMetadataException getting raised; the culprit was found: .NET Native!
If you’re working with Universal Windows Apps (UWP) and don’t know what .NET Native is, I strongly advise you to start by reading the following excellent articles written by Morgan Brown, “a Software Development Engineer on the .NET Native team”:
Here’s the situation right now: when you build a UWP app, the compiler will do some “smart stuff” with your code (let’s skip the technicals here!), squeezing every little bit it can to make sure the compiled result will perform better and faster!
But there is a catch: if your code uses any type of dynamic coding features such as reflection or serialization, you might need to instruct the compiler that certain types in your application will be used as such, in order to avoid the exceptions like the MissingMetadataException you see above.
To avoid such problems, you can add specially built rd.xml files to your project - once again, check the articles above for more information on this subject!
The MultiBindingBehavior works by using the AssociateObject property value to reflect and dynamically create a binding expression, so what I needed was to ensure that it would be able to reflect any object passed to this property.
With this requirement in mind, I created a new Cimbalino.Toolkit.rd.xml file, set its Build Action to Embedded Resource, and set the content to the following:
Aaand… this didn’t work! I started getting a build error message stating that it couldn’t find any AssociatedObject property in the Cimbalino.Toolkit.Behaviors.MultiBindingBehavior.
Granted, the property does not exist directly in this class, but rather in the Behavior<T> base class, so I guess one say that .NET Native compilation completely forgot a completely basic feature of .NET and most object oriented languages: Class Inheritance!
Taking this into account, I made a couple of changes in the file and here’s what in the end made it work:
When working with Universal Windows Apps, make sure to build the app in Release mode and test it thoroughly!
Keep an eye out on the build warnings for any problems with your rd.xml files.
If you’re working with MVVM or have Model representation classes, it might make sense to put these in a separate assembly, or at least in a separate namespace from the rest of the code - this will allow you to easily target these files in a rd.xml for .NET Native optimization exclusion.