Plotting data with gaps in ZedGraph using nullable types / null values

问题

This question is very similar: How to miss points in a zedgraph line graph in c.

I am pulling data from SQL and plotting it using ZedGraph, but I am using nullable types (int?, float? etc.) and would like to create gaps in the plot wherever a null value exists.

Is there a way to have ZedGraph handle these null values, or do I need to convert them all to double.NaN?

回答1:

Casting nullable types to double.NaN seems like the only option when creating the PointPairList for a ZedGraph LineItem (or whatever graph type). Using the null-coalescing operator (??) makes this rather simple:

// example, adding one data point to the list
int? SomeValue = null;
myPointPairList.Add(x, SomeValue ?? double.NaN);

来源：https://stackoverflow.com/questions/6603151/plotting-data-with-gaps-in-zedgraph-using-nullable-types-null-values