c# - 如何 stub DbSet.Find

Question

// acknowledgement: http://stackoverflow.com/a/5022512/1500199
public class FakeDbSet<T> : IDbSet<T> where T : class
{
    private readonly HashSet<T> data;
    private readonly IQueryable query;

    public FakeDbSet()
    {
        data = new HashSet<T>();
        query = data.AsQueryable();
    }

    public virtual T Find(params object[] keyValues)
    {
        throw new NotImplementedException();
    }
}

如何实现Find？

我需要确定 T 的主键值，以便在 Find 方法中执行键值比较，但我不知道如何做。

Answer 1

试试这个:

public class FakeDbSet<T> : IDbSet<T> where T : class
{
    private Func<T, object[], bool> _findSelector
    private readonly HashSet<T> data;
    private readonly IQueryable query;

    public FakeDbSet(Func<T, object[], bool> findSelector)
    {
        _findSelector = findSelector;
        data = new HashSet<T>();
        query = data.AsQueryable();
    }

    public virtual T Find(params object[] keyValues)
    {
        return _data.SingleOrDefault(item => _findSelector(item, keyValues));
    }
}