Xamarin Forms, the MVVMLight Toolkit and I: Dependecy Injection

Xamarin Forms, the MVVMLight Toolkit and I: Dependecy Injection

Xamarin Forms is not always able to call platform specific code without some additional work to do. Thanks to the MVVM pattern, we are already familiar with the solution for this problem: Dependency Injection (DI). This post explains everything you need to know.

Posted by msicc in Android, Dev Stories, iOS, UWP, Xamarin, 5 comments

Xamarin Forms, the MVVMLight Toolkit and I (new series)

In this initial blog post about my new series of how I use MVVMLight with Xamarin.Forms I am showing you how to get the initial setup done, before we go into details in the following blog posts.

Posted by msicc in Android, Dev Stories, iOS, Xamarin, 5 comments

[Updated] How to create a pure icon button for your UWP app

[Updated: the first version of this blog post was using a UserControl. Thanks to a discussion on Twitter, I realized that wrapping it into a UserControl is overblown (yes, sometimes I tend to write more code than necessary). This is the updated version using only a Style for the button.]

When writing apps, you often come along a point where you want to style controls differently than the original style. Today, I‘ll show you a pure icon button that does not show the surrounding shape and borders. Instead, it highlights the icon of the button when hovering over it, while it changes the color to the user’s accent color when it gets pressed. Here is a little animation of what I am talking about:cromeless button demo

It all begins with the default style of the Button control, which you can see here. We are going to modify this Style until it matches the above animation. The first thing we change is the BackgroundBrush – set it to ‘Transparent’ to get rid of the grey shape that the button control comes with when hovering over it or pressing it:

<Setter Property="Background" Value="Transparent"/>

As we want an icon button, we need to choose a common source for the icons as well. I am using a Path Shape as the icon source, as it allows modifications to be done in XAML. So the next step is to add a Path shape to the Style:

                            <Path x:Name="PathIcon"
                                  Data="{TemplateBinding Content}"
                                  Stretch="Uniform"
                                  Fill="{TemplateBinding Foreground}"
                                  Stroke="Transparent"
                                  StrokeThickness="1"
                                  Margin="4"
                                  RenderTransformOrigin="0.5,0.5">
                                <Path.RenderTransform>
                                    <TransformGroup>
                                        <TransformGroup.Children>
                                            <RotateTransform Angle="0" />
                                            <ScaleTransform ScaleX="1" ScaleY="1" />
                                        </TransformGroup.Children>
                                    </TransformGroup>
                                </Path.RenderTransform>
                            </Path>

In this case, as we just want to use the icon within our button, we can safely remove the ‘ContentPresenter’ part in the Style. We have made quite some progress already, but that all does not make the control behaving like in the animation yet.

Now it is the time to modify the CommonStates of the Button’s style. Our Button uses only an icon, so we need to add the color states for the Path’s ‘Fill (=Foreground)’ to the states. Here are the modifications:

‘PointerOver’ state:

                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Fill" Storyboard.TargetName="PathIcon">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseHighBrush}"/>
                                            </ObjectAnimationUsingKeyFrames>

‘Pressed’ state:

                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Fill" Storyboard.TargetName="PathIcon">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlForegroundAccentBrush}"/>
                                            </ObjectAnimationUsingKeyFrames>

‘Disabled’ state:

                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Fill" Storyboard.TargetName="PathIcon">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledBaseMediumLowBrush}"/>
                                            </ObjectAnimationUsingKeyFrames>

To get the icon’s outline highlighting, we are going to use the Path’s ‘Stroke (=Border)’ property. Add these modifications to the Style in XAML:

‘PointerOver’ state:

                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Stroke" Storyboard.TargetName="PathIcon">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightAccentBrush}"/>
                                            </ObjectAnimationUsingKeyFrames>

‘Pressed’ state:

                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Stroke" Storyboard.TargetName="PathIcon">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/>
                                            </ObjectAnimationUsingKeyFrames>

‘Disabled’ state:

                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Stroke" Storyboard.TargetName="PathIcon">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/>
                                            </ObjectAnimationUsingKeyFrames>

All that is left is to use the Style on any desired button:

    <Button x:Name="BaseButton" Style="{StaticResource TransparentButtonStyle}"></Button>

If you now use this one in an application, you will get the same result as in the initial animation.

For easier use, here is the complete code:

        <Style x:Key="TransparentPathIconButtonStyle" TargetType="Button">
            <Setter Property="Background" Value="Transparent"/>
            <Setter Property="Foreground" Value="{ThemeResource SystemControlForegroundBaseHighBrush}"/>
            <Setter Property="BorderBrush" Value="{ThemeResource SystemControlForegroundTransparentBrush}"/>
            <Setter Property="BorderThickness" Value="{ThemeResource ButtonBorderThemeThickness}"/>
            <Setter Property="Padding" Value="8,4,8,4"/>
            <Setter Property="HorizontalAlignment" Value="Stretch"/>
            <Setter Property="VerticalAlignment" Value="Stretch"/>
            <Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}"/>
            <Setter Property="FontWeight" Value="Normal"/>
            <Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}"/>
            <Setter Property="UseSystemFocusVisuals" Value="True"/>

            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="Button">
                        <Grid x:Name="RootGrid" Background="{TemplateBinding Background}">
                            <VisualStateManager.VisualStateGroups>
                                <VisualStateGroup x:Name="CommonStates">
                                    <VisualState x:Name="Normal">
                                        <Storyboard>
                                            <PointerUpThemeAnimation Storyboard.TargetName="RootGrid"/>
                                        </Storyboard>
                                    </VisualState>
                                    <VisualState x:Name="PointerOver">
                                        <Storyboard>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Stroke" Storyboard.TargetName="PathIcon">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightAccentBrush}"/>
                                            </ObjectAnimationUsingKeyFrames>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Fill" Storyboard.TargetName="PathIcon">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseHighBrush}"/>
                                            </ObjectAnimationUsingKeyFrames>
                                            <PointerUpThemeAnimation Storyboard.TargetName="RootGrid"/>
                                        </Storyboard>
                                    </VisualState>
                                    <VisualState x:Name="Pressed">
                                        <Storyboard>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Fill" Storyboard.TargetName="PathIcon">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlForegroundAccentBrush}"/>
                                            </ObjectAnimationUsingKeyFrames>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Stroke" Storyboard.TargetName="PathIcon">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/>
                                            </ObjectAnimationUsingKeyFrames>
                                            <PointerDownThemeAnimation Storyboard.TargetName="RootGrid"/>
                                        </Storyboard>
                                    </VisualState>
                                    <VisualState x:Name="Disabled">
                                        <Storyboard>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Fill" Storyboard.TargetName="PathIcon">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledBaseMediumLowBrush}"/>
                                            </ObjectAnimationUsingKeyFrames>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Stroke" Storyboard.TargetName="PathIcon">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/>
                                            </ObjectAnimationUsingKeyFrames>
                                        </Storyboard>
                                    </VisualState>
                                </VisualStateGroup>
                            </VisualStateManager.VisualStateGroups>

                            <Path x:Name="PathIcon"
                                  Data="{TemplateBinding Content}"
                                  Stretch="Uniform"
                                  Fill="{TemplateBinding Foreground}"
                                  Stroke="Transparent"
                                  StrokeThickness="1"
                                  Margin="4"
                                  RenderTransformOrigin="0.5,0.5">
                                <Path.RenderTransform>
                                    <TransformGroup>
                                        <TransformGroup.Children>
                                            <RotateTransform Angle="0" />
                                            <ScaleTransform ScaleX="1" ScaleY="1" />
                                        </TransformGroup.Children>
                                    </TransformGroup>
                                </Path.RenderTransform>
                            </Path>
                        </Grid>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

As always, I hope this post is helpful for some of you. If you have questions/ideas for improvements or just want to talk about the control, feel free to leave a comment below.

Happy Coding, everyone!

Posted by msicc in Dev Stories, UWP, 3 comments

Playing around with Microsoft Hololens

Yesterday in the morning, Alessandro  invited me to join a meetup targeting the Hololens. As the Hololens is very rare outside the US, I just needed to join the event.

When I arrived, already one of the meetup attendees was introduced to the Hololens. After some time, it was then my turn. The first “challenge” one has to take is to adjust the device on your head. The Hololens has quite some weight – it is a full PC you are wearing on your head, so not much a surprise.

After I mounted the Hololens on my head, I needed to start the calibration app. You have to adjust four corners you are seeing on the display. This is quite a challenge, but once you have it done, you’re ready to go.

GianPaolo recommended me to play level one of the space shooter game “Project X-Ray”, to get a better feeling for the device. You may probably know this from various Microsoft demos already (if not, click here). The game first scans the environment, and then you have to shot down all the alien robots that are coming out of the wall. As much fun as it is, it is challenging (at least at my age). Here is a shot of what I (and others) saw:

hololens2

After that, I tried the Galaxy Explorer app. It is amazing, you can zoom in and out of the point of interests in the 3D galaxy map, pretty much like we know already from some science-fiction movies. Here’s a shot of me in action:

hololens1

One thing needs to be clear. The Hololens does no longer interact with any object like we all are used to. It takes user interaction to a whole new level. You’ll have to learn some gestures, like the “bloom”-gesture to open the start menu. But that’s only how you control the device. We all will be able to add our own ways of interaction in our apps (that we will write one day, I bet!). I have already some ideas what I could do (well, also thanks to my kids and wife, tbh). One of them is a holographic version of my first app I ever wrote (which is a fishing knots tutorial app with animated step-by-step guide).

What about you? Do you have ideas for Hololens apps/games? Sound off in the comments, if you want to share your ideas. You can also find more info on Hololens development here on MSDN.

To close this post, I want to thank the team of IBV Solutions for this absolutely awesome opportunity. Thank you, guys!

Posted by msicc in Editorials, 0 comments
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