private static (ICollection <ReadPlcItemWrapper> Mapping, AGL4.DATA_RW40[] AllAgLinkItems) CreateMappingAndAgLinkItems(ICollection <IPlcItem> plcItems, PlcItemUsageType usageType)
{
var mapping = plcItems
.Select(plcItem => new ReadPlcItemWrapper(plcItem))
.ToArray()
;
// Create all needed AGLink items.
//! Directly storing the AGLink items in the ReadPlcItemWrapper instance won't work, as AGL4.DATA_RW40 is a struct that would consequently be copied on assignment.
//! Therefore the ReadPlcItemWrapper only contains the start position and the amount of items in the returned AGLink items array.
var previousAmount = 0;
var allAgLinkItems = mapping
.SelectMany
(
readPlcItemWrapper =>
{
var agLinkItems = AgLinkPlc.CreateAgLinkItems(readPlcItemWrapper.PlcItem, usageType).ToArray();
readPlcItemWrapper.Start = (previousAmount += agLinkItems.Length) - 1;
readPlcItemWrapper.Amount = agLinkItems.Length;
return(agLinkItems);
}
)
.ToArray()
;
return(mapping, allAgLinkItems);
}
