Creation and registration of the Metro style component for WinRT

The official release of Windows 8 is approaching every day, and more and more developers are thinking about creating their own Metro style app. And if you make several such applications at once, then most likely you will need to use the same code in different projects.

This article provides step-by-step instructions for creating a simple Metro style component, as well as the features of registering such a library for further use in WinRT projects.

As an example of a component, we chose a Metro-style animated download indicator, similar to the one that many of us have already seen in the new version of Windows. By the end of this article, you will not only know everything about component registration, but also be able to add a ready-made download indicator to your Metro application.

System requirements

If you have not had time to write your first program for Windows 8, then make sure that your development environment meets the following requirements:

  • Development should be conducted in the operating system Windows 8 . At the time of this writing, Windows 8 is available in the Release Preview stage and can be downloaded at this link:
  • For development, you will need the Visual Studio 2012 development environment , which is currently in the Release Candidate stage and is available for download from .
    If you are unable to use the professional version of Visual Studio, you can always install Visual Studio Express 2012 for Windows 8 for free. In this article, all the steps will be provided for the interface of the professional version of Visual Studio 2012.

Library creation

So, we launched Visual Studio 2012 and are ready to make our first Metro-style component.
To do this, create a new project of the Class Library type (Metro style apps) and call it MyCustomControls :
As a result, an empty project with one class will be created. Since in our case this class is not needed, we will delete the Class1.cs file from the project:
Then we will add a blank for our future component. To do this, in the Add New Item dialog, select a new template - Templated Control - and give it the name MyCustomControl :

After these actions, two new files will appear in the project:

  • MyCustomControl.cs , containing the definition of our component as an inheritor from the control:

    namespace MyCustomControls {
        public sealed class MyCustomControl : Control {
            public MyCustomControl() {
                this.DefaultStyleKey = typeof(MyCustomControl);

    Replace it with the code below:

    namespace MyCustomControls {
       public sealed class MyCustomControl : Control {
            const double radius = 30;
            public static readonly DependencyProperty DataProperty =
                   DependencyProperty.Register("Data", typeof(Geometry), typeof(MyCustomControl), 
                       new PropertyMetadata(null));
            public Geometry Data {
                get { return (Geometry)GetValue(DataProperty); }
                set { SetValue(DataProperty, value); }
            DispatcherTimer timer;
            double progress = 0.0;
            Size arrangeSize = new Size(0, 0);
            DateTime lastTime = DateTime.Now;
            public MyCustomControl() {
                this.DefaultStyleKey = typeof(MyCustomControl);
                timer = new DispatcherTimer();
                timer.Tick += timer_Tick;
                timer.Interval = TimeSpan.FromMilliseconds(5);
            void timer_Tick(object sender, object e) {
                DateTime time = DateTime.Now;
                progress += 0.5 * (time - lastTime).TotalSeconds;
                lastTime = time;
                if (progress > 1)
                    progress -= 1;
                Data = CreateGeometry(progress);
            double CalcAngle(double progress) {
                double factor = 0.5 * Math.Cos(Math.PI * progress - Math.PI) + 0.5;
                return 2 * Math.PI * factor;
            double CalcDistance(double angle) {
                return 0.3 * (Math.PI - Math.Abs(Math.PI - angle));
            Geometry CreateGeometry(double progress) {
                double angle = CalcAngle(progress);
                double distance = CalcDistance(angle);
                GeometryGroup newGeometry = new GeometryGroup() { FillRule = FillRule.Nonzero };
                for (int i = 3; i > -4; i--) {
                    Point location = 
                        new Point(0.5 * arrangeSize.Width 
                                             + radius * Math.Cos(angle + i * distance - Math.PI / 2),
                                  0.5 * arrangeSize.Height 
                                             + radius * Math.Sin(angle + i * distance - Math.PI / 2));
                        newGeometry.Children.Add(new EllipseGeometry() { 
                                  Center = location, RadiusX = 5, RadiusY = 5 });
                return newGeometry;
            protected override Size MeasureOverride(Size availableSize) {
                return new Size(!double.IsInfinity(availableSize.Width) ? availableSize.Width : 0,
                    !double.IsInfinity(availableSize.Height) ? availableSize.Height : 0);
            protected override Size ArrangeOverride(Size arrangeBounds) {
                arrangeSize = arrangeBounds;
                return base.ArrangeOverride(arrangeBounds);

  • Themes \ Generic.xaml , where is the description of the style that will be applied by default to our control. Add the Path element to the markup :

        <Style TargetType="local:MyCustomControl">
            <Setter Property="Template">
                    <ControlTemplate TargetType="local:MyCustomControl">
                            Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}">
                            <Path Fill="Aqua" Data="{Binding Path=Data, 
                                  RelativeSource={RelativeSource TemplatedParent} }"/>

Then you can quickly test the operation of the written component. To do this, add another project of the Blank App (XAML) type :
Now add a link (of the Project Reference type) to our MyCustomControls assembly to this project :
Next, change the contents of the MainPage.xaml file , as shown below:


    <Grid Background="White">
        <my:MyCustomControl />

Then we’ll start the application App1 :
Now we launch our project and see the download indicator in the Metro style - which means that our component is operational!

Create Extension SDK

Now you can go directly to creating your own Extension SDK. Using the Extension SDK, you can combine several libraries into one set, which can be connected to a Visual Studio project by adding one link to the entire SDK at once.

First, create the following directory structure on your hard drive that will contain everything you need for our SDK:
— — 1.0
— — — — References\CommonConfiguration\neutral\MyCustomControls.dll
— — — — Redist\CommonConfiguration\neutral\MyCustomControls.pri
— — — — Redist\CommonConfiguration\neutral\MyCustomControls\Themes\generic.xaml
— — — — SDKManifest.xml

In this structure, the MySDK is the root folder containing all the other SDK files. It can have any name that reflects the name of your SDK. 1.0 is the version of your SDK.

The References directory should contain all the modules that will be included in the SDK, assembled in the appropriate configuration and for a specific architecture. That is, the next level defines the configuration, and perhaps only three options: Debug , Retail and CommonConfiguration . The last level, respectively, indicates what architecture these modules were collected for: neutral , x64 , x86, and ARM . In this case, an assembly was made in Debug or Release under AnyCPU .

The Redist directory contains the files that are needed for debugging and execution, and they will be packaged in a package. And again, it all depends on the configuration and architecture - exactly the same as for References .

The SDKManifest.xml file must have the following contents:

<?xml version="1.0" encoding="utf-8" ?>
<FileList DisplayName="My Custom Controls" ProductFamilyName="My Controls" MinVSVersion="11.0" MinToolsVersion="4.0" CopyRedistToSubDirectory="." AppliesTo="WindowsAppContainer+WindowsXAML+Managed">
<File Reference="MyCustomControls.dll">

This file describes all the assemblies that are in the References folder . The CopyRedistToSubDirectory parameter specifies where the files from the Redist folder will be copied relative to the root of the package. We set it as "." - this means that all files will be copied to the root of the package.

Register Extension SDK

Now you can register your SDK in one of the following ways:

  • copy the MySDK folder to the "% ProgramFiles% \ Microsoft SDKs \ Windows \ v8.0 \ Extension SDKs \" folder
  • add a key to the registry, which will contain the path to our SDK. I will give an example of a * .reg file that will add the corresponding data to the registry:
    [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SDKs\Windows\v8.0\ExtensionSDKs\MySDK\1.0]

After the SDK has been created and registered, you can create a new test project of the type Blank App (XAML) .

At the same time, we see that when adding a link to MyCustomControls.dll in the Windows-> Extentions section, MySDK will be visible .

To check whether everything works in this case, we modify the MainPage.xaml file in the same way as we did in the previous test example, then we collect and run the project - and we see our loading indicator in action!

useful links

More detailed information on how to create your Extension SDK can be found at the following link:
If you want to get to know WinRT more deeply, here are the links other useful resources: