保持画布元素相对于背景图像的位置

我试图在我的Canvas相对于我的背景定位元素。

窗口重新调整大小，保持长宽比。背景随着窗口的大小而拉伸。

问题是一旦窗口大小被重新调整元素的位置是不正确的。如果窗口只是稍微调整一下大小，元素会稍微调整一下它们的大小，并且仍然在正确的位置，但是如果窗口的大小是它的两倍，那么定位就完全取消了。

到目前为止，我使用Grid，但它是无效的，以及。这里是XAML

<Window x:Class="CanvasTEMP.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow"  ResizeMode="CanResizeWithGrip" SizeToContent="WidthAndHeight" MinHeight="386" MinWidth="397.5" Name="MainWindow1"
    xmlns:c="clr-namespace:CanvasTEMP" Loaded="onLoad" WindowStartupLocation="CenterScreen" Height="386" Width="397.5" WindowStyle="None" AllowsTransparency="True" Topmost="True" Opacity="0.65">
<ItemsControl ItemsSource="{Binding}">
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <Canvas Height="77" Width="218">
                <Label Content="{Binding OwnerData.OwnerName}" Height="36" Canvas.Left="8" Canvas.Top="55" Width="198" Padding="0" HorizontalAlignment="Left" HorizontalContentAlignment="Center" VerticalAlignment="Center"/>
            </Canvas>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
    <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
            <Canvas>
                <Canvas.Background>
                <ImageBrush ImageSource="Resources'default_mapping.png" Stretch="Uniform"/>
                </Canvas.Background>
            </Canvas>
        </ItemsPanelTemplate>
    </ItemsControl.ItemsPanel>
    <ItemsControl.ItemContainerStyle>
        <Style TargetType="ContentPresenter">
            <Setter Property="Canvas.Left" Value="{Binding OwnerData.left}" />
            <Setter Property="Canvas.Top" Value="{Binding OwnerData.top}" />
        </Style>
    </ItemsControl.ItemContainerStyle>
</ItemsControl>

用于数据绑定的类

public class Owner : INotifyPropertyChanged
{
    public double _left;
    public double _top;
    public string OwnerName { get; set; }
    public double top { get { return _top; }
        set
        {
            if (value != _top)
            {
                _top = value;
                OnPropertyChanged();
            }
        }
    }
    public double left
    {
        get { return _left; }
        set
        {
            if (value != _left)
            {
                _left = value;
                OnPropertyChanged();
            }
        }
    }
    public string icon { get; set; }
    public event PropertyChangedEventHandler PropertyChanged;
    private void OnPropertyChanged([CallerMemberName] string propertyName = "none passed")
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null)
            handler(this, new PropertyChangedEventArgs(propertyName));
    }
}
public class ForDisplay
{
    public Owner OwnerData { get; set; }
    public int Credit { get; set; }
}

这里是每秒运行的代码，以保持元素的位置相对于窗口大小

items[0].OwnerData.left = this.Width * (10 / Defaul_WindowSize_Width); 
items[0].OwnerData.top = this.Height * (55 / Defaul_WindowSize_Height);

10和50是初始化窗口时使用的默认Canvas.Left和Canvas.Top。

如果有人能指出我做错了什么，我将不胜感激。

public static readonly DependencyProperty RelativeProperty = 
    DependencyProperty.RegisterAttached("Relative", typeof(double), typeof(MyControl));
public static double GetRelative(DependencyObject o)
{
    return (double)o.GetValue(RelativeProperty);
}
public static void SetRelative(DependencyObject o, double value)
{
    o.SetValue(RelativeProperty, value);
}

public class RelativePositionConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        var rel = (double)values[0];
        var width = (double)values[1];
        return rel * width;
    }
    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

var child = new Child();
SetRelative(child, currentPosition / ActualWidth);
var multiBinding = new MultiBinding { Converter = new RelativePositionConverter() };
multiBinding.Bindings.Add(new Binding { Source = child, Path = new PropertyPath(RelativeProperty) });
multiBinding.Bindings.Add(new Binding { Source = canvas, Path = new PropertyPath(ActualWidthProperty) });
BindingOperations.SetBinding(child, LeftProperty, multiBinding);
Children.Add(child);