WPF ViewBox 横竖屏适配异常问题求助

各位大佬，我在WPF开发中碰到了ViewBox的适配难题：窗口横屏显示时界面一切正常，但切换到竖屏模式后，界面就变得几乎没法用了！我找了好多相关示例，都没找到能解决这个问题的方案，有没有朋友能给点思路呀？

我的XAML代码如下：

<Viewbox Stretch="Fill" StretchDirection="Both" Name="ViewBox1">
    <Canvas Height="778" Width="1219" >
        <Canvas.Background>
            <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                <GradientStop Color="#FFD6D6D6" Offset="0.596" />
                <GradientStop Color="White" Offset="0.163" />
                <GradientStop Color="White" Offset="1" />
            </LinearGradientBrush>
        </Canvas.Background>
        <Image x:Name="HintergrundImage" HorizontalAlignment="Left" Height="277" Width="590" Source="Images/MyPresent.jpg" Stretch="Fill" Canvas.Left="307" Canvas.Top="10"/>
        <Button Canvas.Left="307" Canvas.Top="304" Height="101" x:Name="PBNormal" Width="590" TabIndex="1082" Click="PBNormal_Click" >
            <Button.ToolTip>
                <StackPanel>
                    <WrapPanel>
                        <Image MinWidth="20" MinHeight="20" MaxWidth="20" MaxHeight="20" Margin="0,0,5,0" Source="Images/Planen.jpg" />
                        <TextBlock Margin="0,0,0,5" FontSize="14" FontWeight="Bold"><Run Text="Planung"/></TextBlock>
                    </WrapPanel>
                    <TextBlock><Run Text="Planung"/></TextBlock>
                </StackPanel>
            </Button.ToolTip>
            <StackPanel Height="95" Width="575" Orientation="Horizontal" FlowDirection="LeftToRight" >
                <Image x:Name="buttonPlanung" Width="71" MouseLeftButtonDown="buttonPlanung_Click" Source="Images/Planen.jpg" Margin="0,0,0,1" />
                <TextBlock x:Name="permPlanung" Canvas.Left="22" Canvas.Top="0" FontSize="9" FontWeight="Bold" Margin="2,0,0,0">
                    <InlineUIContainer>
                        <AccessText Width="469" Height="59" Text=" My Button XYZ" FontSize="40" HorizontalAlignment="Center" VerticalAlignment="Center" TextTrimming="WordEllipsis" TextWrapping="Wrap" Margin="11,16,0,0" />
                    </InlineUIContainer>
                </TextBlock>
            </StackPanel>
        </Button>
        <Button x:Name="ButtonHochformat" Content="Hochformat" Canvas.Left="1056" Canvas.Top="167" Width="75" Click="ButtonHochformat_Click"/>
        <Button x:Name="ButtonQuerformat" Content="Querformat" Canvas.Left="1056" Canvas.Top="240" Width="75" Click="ButtonQuerformat_Click"/>
    </Canvas>
</Viewbox>

有没有大佬能帮忙看看问题出在哪呀？

内容来源于stack exchange