C＃泛型装箱错误

Question

I have the following code that worked before I changed to use generics for the service:

Update: I added some more class and interface info in response to comments:

public class Service<T1,T2> : BaseService, IService<T1>
        where T1 : IAuditableTable
        where T2 : IAuditableTable
{
    private IAzureTable<T1> _T1repository;
    private IAzureTable<T2> _T2repository;

    public Service(string ds)
    {
        base.Initialize(ds);
        _T1repository = StorageHelper.GetTable<T1>(ds);
        _T2repository = StorageHelper.GetTable<T2>(ds);
    }

    public IEnumerable<AdminDetail> ShowDetails()
    {
        return base.ShowDetails(_T1repository, _T2repository);
    } 

    ...

and

public IEnumerable<AdminSummary> ShowSummary<T1, T2>(
        IAzureTable<T1> master, IAzureTable<T2> detail)
    where T1 : AuditableTable
    where T2 : AuditableTable
{
    ...

public abstract class AuditableTable : TableServiceEntity, IAuditableTable  
{
    ...

public interface IAzureTable<T> : IInitializer

public interface IService<T>
        where T : IAuditableTable
    {
        IEnumerable<AdminSummary> ShowSummary();
    }

private IService<Account> _account;
vm.AdminSummaries = _account.ShowSummary(); << calls the report

When I try to compile I get the following message:

The type 'T2' cannot be used as type parameter 'T2' in the generic type or method 'Services.BaseService.ShowSummary<T1,T2>(AzureToolkit.IAzureTable<T1>, AzureToolkit.IAzureTable<T2>)'. There is no boxing conversion or type parameter conversion from 'T2' to 'Storage.Models.AuditableTable'.

Answer 1

The ShowSummary needs types of AuditableTable (which does implement IAuditableTable ). You supply values of just IAuditableTable where it needs the concrete class. The other way around (concrete implementation in parameter of interface type) would probably work.

Answer 2

您可能需要对T2的class约束。