Custom X/Y grid line in MSChart control

I have a C# windows form with a simple 2D line chart that I want to add custom X or Y axis markers to, and d开发者_运维技巧raw a custom grid line (in a highlighted color, dotted line for example). I have looked at the customLabels property, but this seems to override the default grid, which I still want to display. This is to illustrate something like a threshold or a cutoff. How can I do this with the MSChart control?

Many thanks

Could you achieve what you want with striplines?

In the ms chart samples (get it here http://archive.msdn.microsoft.com/mschart), inside the "Using Custom Labels" section, they use striplines on the Y axis which are quite effective at highlighting ranges of values. They also do not affect the grid ... I checked that by changing the sample code a little so I could easily move the boundaries of the striplines around (see below).

double low_med = 17; // was 30
double med_hi = 92;  // was 70

// Set Y axis custom labels
axisY.CustomLabels.Add(0, low_med, "Low");
axisY.CustomLabels.Add(low_med, med_hi, "Medium");
axisY.CustomLabels.Add(med_hi, 100, "High");

StripLine stripLow = new StripLine();
stripLow.IntervalOffset = 0;
stripLow.StripWidth = low_med;
stripLow.BackColor = Color.FromArgb(64, Color.Green);

StripLine stripMed = new StripLine();
stripMed.IntervalOffset = low_med;
stripMed.StripWidth = med_hi - low_med;
stripMed.BackColor = Color.FromArgb(64, Color.Orange);

StripLine stripHigh = new StripLine();
stripHigh.IntervalOffset = med_hi;
stripHigh.StripWidth = 100 - med_hi;
stripHigh.BackColor = Color.FromArgb(64, Color.Red);

axisY.StripLines.Add(stripLow);
axisY.StripLines.Add(stripMed);
axisY.StripLines.Add(stripHigh);