In your interface you have it defined as
Task<IEnumerable<TabMain>> Gettabs();
but you implement it like this
public async Task<IEnumerable<TabMain>> GetTabs()
C# is a case sensitive language, so you need to either change your implementation method name or your interface method name. I would change the interface method name to GetTabs
to go with the standard naming convention
0
solved asp.net web api c# interface dataprovider