I am using Oxyplot to draw heatmap for a WPF project and needed to draw a crosshair that moves according to user clicks. Since I couldn't find any good example or documentation on the topic, I made a small hack by using LineAnnotations and by over-riding Oxyplot mouse click event. Here is the sample code using WPF with MVVM pattern- MainWindow.xaml <Grid> <oxy:Plot x:Name="CrossHairPlot"> <oxy:Plot.Axes> <oxy:LinearAxis Key="MyXAxis" Position="Bottom" IsZoomEnabled="False"/> <oxy:LinearAxis Key="MyYAxis" Position="Left" IsZoomEnabled="False"/> <oxy:LinearColorAxis Key="...