问题是在布局传递之后应用了变换.您应该在计算布局之前使用 LayoutTransform 执行转换:

The problem is that the Transforms were applied after the layout pass. You should use a LayoutTransform to perform the transformation before the layout is calculated:

<Image Name="ImageTarget" HorizontalAlignment="Left" VerticalAlignment="Top" Stretch="Uniform" RenderTransformOrigin=".5,.5">
<Image.LayoutTransform>
    <TransformGroup>
        <ScaleTransform ScaleX="{Binding Main.BindedViewMode, Converter={StaticResource ImageSizeConverter}}" />
        <ScaleTransform ScaleY="{Binding Main.BindedViewMode, Converter={StaticResource ImageSizeConverter}}" />
        <RotateTransform Angle="-90" />
    </TransformGroup>
</Image.LayoutTransform>