中心圖像內畫布

Question

我有一個Image內Canvas：

<Canvas> 
    <Image HorizontalAlignment="Center" VerticalAlignment="Center" /> 
</Canvas> 

我想要顯示的Image總是（甚至之後可能的調整大小）在我Canvas的中心，但以這種方式圖像被繪製在左上角。我能怎麼做？

Answer 1

如果您更改圖像和畫布的大小，這個問題最酷的事情是它會起作用。 轉換代碼：

internal sealed class CenterConverter : IMultiValueConverter 
{ 
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture) 
    { 
     double canvasWidth = System.Convert.ToDouble(values[0]); 
     double canvasHeight = System.Convert.ToDouble(values[1]); 
     double controlWidth = System.Convert.ToDouble(values[2]); 
     double controlHeight = System.Convert.ToDouble(values[3]); 
     switch ((string)parameter) 
     { 
      case "top": 
       return (canvasHeight - controlHeight)/2; 
      case "bottom": 
       return (canvasHeight + controlHeight)/2; 
      case "left": 
       return (canvasWidth - controlWidth)/2; 
      case "right": 
       return (canvasWidth + controlWidth)/2; 
      default: 
       return 0; 
     } 
    } 

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture) 
    { 
     throw new NotImplementedException(); 
    } 
} 

XAML，在資源的地方：

<local:CenterConverter x:Key="CenterConverter" /> 

XAML：

<Canvas x:Name="superCoolCanvas"> 
    <Image x:Name="superCoolImage" > 
     <Canvas.Top> 
      <MultiBinding Converter="{StaticResource CenterConverter}" ConverterParameter="top"> 
       <Binding ElementName="superCoolCanvas" Path="ActualWidth" /> 
       <Binding ElementName="superCoolCanvas" Path="ActualHeight" /> 
       <Binding ElementName="superCoolImage" Path="ActualWidth" /> 
       <Binding ElementName="superCoolImage" Path="ActualHeight" /> 
      </MultiBinding> 
     </Canvas.Top> 
     <Canvas.Left> 
      <MultiBinding Converter="{StaticResource CenterConverter}" ConverterParameter="left"> 
       <Binding ElementName="superCoolCanvas" Path="ActualWidth" /> 
       <Binding ElementName="superCoolCanvas" Path="ActualHeight" /> 
       <Binding ElementName="superCoolImage" Path="ActualWidth" /> 
       <Binding ElementName="superCoolImage" Path="ActualHeight" /> 
      </MultiBinding> 
     </Canvas.Left> 
    </Image> 
</Canvas> 

Answer 2

帆布打算使用絕對座標。您可以使用dwrd提供的解決方案，也可以將Canvas和Image放入網格中，然後將圖像置於該網格中。