Rob,

Thanks for the offer yet this is prop app so I can't expose the source code, and creating an additional sample is not an option for now. When time allows I will try to create a sample and if i manage to, a separate thread will be created. This thread can be closed - i got what i need.

Thanks.

Alex

Hi Alex,

Was the performance bad before making the marker changes or did it occur after the fact?  Would you be able to send me a sample that demonstrates the performance issue?  I can take a look and see if there is anything that can be done to improve it.

Hi Rob,

Thanks for the hint, it worked for me, yet perfomance is still crippled upon zooming in/out but i think its cause is elsewhere.

Alex

Hi Alex,

I'm not sure why it would degrade scrolling performance but probably the simplest way to resolve this would be to apply a TranslateTransform to a custom marker template.  You can keep it from translating in the legend by binding the RenderTransform property to a RelativeSource binding that looks for the Marker object as an ancestor.  This binding will have a converter on it and when it finds a Marker, the converter will do the translation.  If it doesn't find the marker, this means it's inside the legend so it won't apply the translation. 

public class MarkerPositionConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        // the marker is not inside the legend so return an offset
        if (value != null)
            return new TranslateTransform { X = 0, Y = double.Parse(parameter.ToString()) };

        return new TranslateTransform { X = 0, Y = 0 };
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
} 

<local:MarkerPositionConverter x:Key="MarkerPositionConverter"/>
<DataTemplate x:Key="MarkerTemplate">
    <Rectangle Width="20" Height="20" Fill="Red"
               RenderTransform="{Binding RelativeSource={RelativeSource AncestorType={x:Type ig:Marker}}, Converter={StaticResource MarkerPositionConverter}, ConverterParameter=20}">
    </Rectangle>
</DataTemplate>

The converter parameter is what offset you want to apply to the marker.  If you need both an X and Y offset then you can modify the converter paramter to accept two values (ConverterParameter='0,0') and then in the converter, parse the parameter argument for the X and Y values.

This what I was looking for. Both markers has underlying value of 0, the difference should've been in the alignment.

    \/
0 ---------
    /\

By default, i was something like this:

0 ---><--- 

I have found two solutions for this problem, both are based on using RenderTransform set to Translate.

If set to marker, such approach ruins the legend.

If set to ScatterSeries, works almost as expected but it looks as scroll performance degradates.

So i wonder if there is any better solution.