iOS CSV Writing: InvalidOperationException: No public parameterless constructor found.

[yalfers]

I saw this come up in a few issues, but I was unable to find any relating to writing a csv. Hopefully this isn't a complete duplicate..

Anyway, I'm writing to csv and it's working on all platforms outside of iOS.

using (StreamWriter writer = new StreamWriter(Application.persistentDataPath + "/output.csv"))
  using (CsvWriter csv = new CsvWriter(writer))
  {
       csv.Configuration.RegisterClassMap<MyClass.MyClassMap>();
       csv.WriteRecords(_myclass.MyClass as IEnumerable);
 }

Is there an alternative way to write to CSV, identical to how I am above? I have not been able to find a workaround, but I'm sure I'm missing something obvious.

[JoshClose]

You can't use WriteRecords, WriteRecord, GetRecords or GetRecord because they use System.Linq.Expressions, which iOS doesn't allow. You'll need to loop the records and do csv.WriteField(obj.Property).

It looks like there is a new Expression<TDelegate>.Compile(bool) that may allow for this. https://docs.microsoft.com/en-us/dotnet/api/system.linq.expressions.expression-1.compile?view=netframework-4.7.2#System_Linq_Expressions_Expression_1_Compile_System_Boolean_

I'll have to look into that a little more and see if this will allow for this in iOS now.

[JoshClose]

Looks like dotnet might just do it for you. https://stackoverflow.com/a/42033899/68499

Are you using the netstandard version of CsvHelper?

[yalfers]

I'm running off the Unity build, so I'm a little limited here.

[JoshClose]

Off the Unity build of CsvHelper?

[Insofan]

You can't use WriteRecords, WriteRecord, GetRecords or GetRecord because they use System.Linq.Expressions, which iOS doesn't allow. You'll need to loop the records and do csv.WriteField(obj.Property).

It looks like there is a new Expression<TDelegate>.Compile(bool) that may allow for this. https://docs.microsoft.com/en-us/dotnet/api/system.linq.expressions.expression-1.compile?view=netframework-4.7.2#System_Linq_Expressions_Expression_1_Compile_System_Boolean_

I'll have to look into that a little more and see if this will allow for this in iOS now.

Does it support on ios now? It seems .net 8 support linq, but i got this issue