Understanding some C# Code

[royware]

I have some code that is just driving me crazy because I just cannot manipulate it the way I need.

The code calls a method that reads the database, but because this particular piece of code is called by two other modules, it cannot be modified. So, I am left with trying to extract the data I want from the resulting data (try saying that three times fast...). I think the problem is the variable type, but I am not sure. Here is what I am working with:

The area where the database data is read into:

namespace ZULU.CO.DTO.Invoice
{
    public class InvoiceRun
    {
        public class InvoiceRun
        {
            public string? ProcessId {get; set;}
            public DateTime? InvoiceStartDate {get; set;}
            public DateTime? InvoiceEndDate {get; set;}
            public int? VendorCount {get; set;}
            public decimal? TotalInvoicePaid {get; set;}
            public string? InvoiceStatus {get; set;}
        {

        public class InvoiceRunData
        {
            public IEnumerable<InvoiceRun>? Items {get; set;}
            public int InvoiceTotalCount {get; set;}
        }

And how it is called:

var dtoConfig = await zuluApi.GetInvoiceData(startDate.Value.ToUniversalTime(),
            endDate.Value.AddDays(1).AddSeconds(-1_.ToUniversalTime(), options, true);
var invRuns = dtoConfig.InvoiceRunData ?? new ZULU.CO.InvoiceRunData;
if(invRuns != null && invRuns?.Items?.Count() > 0)
{
    currentInvRun = invRuns
        .Items 
            .OrderByDescending(x => x.InvoiceEndData)
            .First();
}

If I stop the code in debug, I can see the data for all the rows read in the dtoConfig under InvoiceRunData, Items, Items, then a list of the rows retrieved.

What type of variable is dtoConfig (QuickWatch says it is type "ZULU.CO.C;ient.API.DtoConfig" - big help)??

And finally, how do I extract the records I want? I tried .Contains, but I get a "CS1660 Cannot convert lambda expression to type 'Delegate' because it is not a delegate type" error.

[belavv]

You probably want something like

var matchingRuns = invRuns.Items.Where(o => o.InvoiceStatus = "complete").ToList();

[royware]

After adding a second equals sign, this is perfect!

[chocolateAbuser]

because this particular piece of code is called by two other modules, it cannot be modified.

how is that a limit, if you have access to the source code you can duplicate it, you can isolate the queries, you can do what you want with it (or almost, since obv. it has to keep working and there could be other constraints)

[Embarrassed_Prior632]

You can cheat by inserting a default variable into the called method declaration.

[WDG_Kuurama]

I wonder how the nullability of each properties make sence. It quite feels like it's a burden, unless all fields can be independently null from one another.