MaterialControls and WPF

[kineese]

Hey there,

first of all thanks for the Material Design controls! Due the possibility to generate a WPF application with Xamarin Forms I tried it out and got a weird behaviour when using the MaterialEntry: When I bind the the Text-Property of the MaterialEntry I get a Argumentexception "Width and height cant be a negative number". The same Exception occurs when just entering some text. Leaving out the binding works fine. I checked out the behaviour when using a normal Entry Control and it works fine. This problem only occurs on WPF. This is my xaml.

<ContentPage.Content>
        <StackLayout Orientation="Vertical" HorizontalOptions="CenterAndExpand" VerticalOptions="StartAndExpand"
                     Padding="16" Spacing="20" WidthRequest="250" BackgroundColor="{StaticResource PrimaryColorLight}">
            <Label Style="{StaticResource H5}" Text="{Binding Message}"
                   TextColor="{StaticResource PrimaryTextColor}" />
            <materialForms:MaterialEntry Text="{Binding Amount}" Placeholder="Anzahl"
                                         AccentColor="{StaticResource PrimaryTextColor}"
                                         Keyboard="Numeric" />
            <materialForms:MaterialPicker Items="{Binding Items}" SelectedItem="{Binding SelectedItem}"
                                          AccentColor="{StaticResource PrimaryTextColor}"
                                          Placeholder="Einheit" />
            <StackLayout Orientation="Horizontal" HorizontalOptions="EndAndExpand">
                <materialForms:MaterialButton Text="ABBRECHEN" BackgroundColor="Transparent"
                                              TextColor="{StaticResource PrimaryTextColor}" Clicked="Abort"
                                              FontFamily="{StaticResource RobotoFontRegular}" HorizontalOptions="End" />
                <materialForms:MaterialButton Text="SPEICHERN" BackgroundColor="Transparent"
                                              TextColor="{StaticResource PrimaryTextColor}"
                                              FontFamily="{StaticResource RobotoFontRegular}"
                                              HorizontalOptions="End" Clicked="ExecuteAction" />
            </StackLayout>
        </StackLayout>
    </ContentPage.Content>

Here is the Stacktrace:

Unbehandelte Ausnahme: System.ArgumentException: Breite und Höhe dürfen keine negative Zahl sein.
   bei System.Windows.Size..ctor(Double width, Double height)
   bei Xamarin.Forms.Platform.WPF.FormsPanel.MeasureOverride(Size availableSize) in D:\a\1\s\Xamarin.Forms.Platform.WPF\FormsPanel.cs:Zeile 70.
   bei System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   bei System.Windows.UIElement.Measure(Size availableSize)
   bei System.Windows.ContextLayoutManager.UpdateLayout()
   bei System.Windows.ContextLayoutManager.UpdateLayoutCallback(Object arg)
   bei System.Windows.Media.MediaContext.InvokeOnRenderCallback.DoWork()
   bei System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks()
   bei System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget)
   bei System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget)
   bei System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   bei System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
   bei System.Windows.Threading.DispatcherOperation.InvokeImpl()
   bei System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
   bei MS.Internal.CulturePreservingExecutionContext.CallbackWrapper(Object obj)
   bei System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   bei System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   bei System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   bei MS.Internal.CulturePreservingExecutionContext.Run(CulturePreservingExecutionContext executionContext, ContextCallback callback, Object state)
   bei System.Windows.Threading.DispatcherOperation.Invoke()
   bei System.Windows.Threading.Dispatcher.ProcessQueue()
   bei System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   bei MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   bei MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
   bei System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   bei System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
   bei System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
   bei MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
   bei MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
   bei System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
   bei System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
   bei System.Windows.Application.RunDispatcher(Object ignore)
   bei System.Windows.Application.RunInternal(Window window)
   bei System.Windows.Application.Run(Window window)
   bei System.Windows.Application.Run()
   bei REA.MDE.Wpf.App.Main()

I know your controls are supposed to be used on Android iOS (and maybe UWP) but because they are based on the Entry-Control I gave it a shot.