Convert RepeatedField to List

.Net

My protobuf file:

message Result{
    repeated ListOfStrings lists = 1;
}

message ListOfStrings {
    repeated string strings = 1;
}

And I have a class with this property:

public List<List<string>> ListOfLists { get; set; }

Protobuf compiler generates RepeatedField collection and when I'm trying to pass this collection to ListOfLists.AddRange() I get this error:

cannot convert from 'Google.ProtobufCollections.RepeatedField<gRPC.ListOfStrings>' to 'System.Collection.Generic.IEnumerable<System.Collections.Generic.List<string>>

How to deal with it?

A List<List<string>> is not the same as a list of things that have strings. You will probably need:

foreach (var list in outerList) {
    var inner = new ListOfStrings();
    inner.Strings.AddRange(list);
    obj.Lists.Add(inner);
}