Question

我正在试图弄清楚如何获取在Canvas控件上设置为背景的图像的“视图大小”。背景设置为ImageBrush，strech设置为UniForm 如果strech属性设置为Fill，那么我可以使用画布的ActualWidth和ActualHeight。

这对UniForm来说是不可能的，所以我该如何处理呢？

这是我的XAML：

<Grid DataContext="{Binding ImageViewerVM.CurrentImage}">
    <controls:RubberBandingCanvas x:Name="RubCanvas">
        <controls:RubberBandingCanvas.Resources>
            <Converters:ControlVisibilityConverter x:Key="VisibilityHiddenConverter" />
            <Converters:StringToBitmapConverter x:Key="StringToBitmapConverter" />
        </controls:RubberBandingCanvas.Resources>
        <controls:RubberBandingCanvas.Background>
            <ImageBrush x:Name="ibCurrentImage" ImageSource="{Binding Path=Path, Converter={StaticResource StringToBitmapConverter}}" Stretch="Uniform"></ImageBrush>
        </controls:RubberBandingCanvas.Background>
        <Ellipse Canvas.Top="10" Canvas.Right="10" Fill="Red" Stroke="Black" Height="15" Width="15" Visibility="{Binding Path=IsMultiTiff, Converter={StaticResource VisibilityHiddenConverter}}"/>            
    </controls:RubberBandingCanvas>
</Grid>

最好的问候，
Jesper Jensen

Answer 1

无法获得开箱即用的ImageBrush的实际大小。我会做的是根据Canvas RenderSize手动计算这个大小。

var ratio = Math.Min(RubCanvas.RenderSize.Width / CanvasBackground.ImageSource.Width, RubCanvas.RenderSize.Height / CanvasBackground.ImageSource.Height);
var imageBrushWidth = CanvasBackground.ImageSource.Width * ratio;
var imageBrushHeight = CanvasBackground.ImageSource.Height * ratio;

获取画布背景的图像画笔控件的实际大小

1 个答案: