We really need to be able to set the line thickness used in the legned - this is a popular request that has never been properly answered. Currently line series in the legend are all shown as 1px lines. This is not sufficient to distiguish between solid and dotted or different colours on very high pixel density (retina) screens that are becoming very popular now. Even setting the line tickness in the custom draw event doesn't work. I have seen there are arguments about it failing it the line is wider that the bounding area for the marker but that just requires a cap at that size - not fixing it to 1px. Also application testing should highlight that this is a problem if someone adds custom draw code with a bad value. To work around this at present we would have to re-implement the various line drawing styles and draw our own images at runtime - if we are technically able to do that and apply sense not to corrupt the legend and go outside bounds then surely the core product should be able to.
There is no good reason why this should not be made to work as people would expect.
C#private void chartControl1_CustomDrawSeries(object sender, CustomDrawSeriesEventArgs e)
{
((LineDrawOptions)e.LegendDrawOptions).LineStyle.Thickness = 3;
}