How initializes this is code with IObjectSet?

I have this code:

public interface IEntityBase<T> where T : struct, IComparable
{
    T? ID { get; set; }
}

And,

p开发者_StackOverflow社区ublic class EntityBase<T> : IEntityBase<T> where T : struct, IComparable
{
    private T? _id;

    protected EntityBase(T? key)
    {
        this._id = key;
    }

    public virtual T? Id
    {
        get { return this._id; }
        set { this._id = value; }
    }

    public override bool Equals(object entity)
    {
        if (entity == null || !(entity is EntityBase<T>))
        {
            return false;
        }

        return (this == (EntityBase<T>)entity);
    }

    public static bool operator ==(EntityBase<T> left, EntityBase<T> right)
    {
        if ((object)left == null && (object)right == null)
        {
            return true;
        }

        if ((object)left == null || (object)right == null)
        {
            return false;
        }

        if (left.Id.Value.CompareTo(right.Id.Value) != 0)
        {
            return false;
        }

        return true;
    }

    public static bool operator !=(EntityBase<T> left, EntityBase<T> right)
    {
        return (!(left == right));
    }

    public override int GetHashCode()
    {
        return this._id.HasValue ? this._id.Value.GetHashCode() : 0;
    }
}

too, MyContext Code:

but in ObjectSet function, appearance error messages!

What is correct syntax?

public class MyContext : ObjectContext
{
    private IObjectSet<Page> _pageSet;

    public MyContext(EntityConnection connection)
        : base(connection)
    {
    }

    public IObjectSet<Page> PageSet
    {
        get
        {
            return _pageSet ?? (_pageSet = ObjectSet<Page>());
        }
    }

    public virtual IObjectSet<TEntity> ObjectSet<TEntity>() where TEntity : struct, EntityBase<TEntity>, IComparable
    {
        return CreateObjectSet<TEntity>();
    }
}

class Page:

public class Page : EntityBase<long>
{
    public Page(long? key)
        : base(key)
    {
    }

    public virtual string Title { get; set; }
    public virtual string Body { get; set; }
    public virtual Page Parent { get; set; }
}

thanks!

With this line:

public virtual IObjectSet<TEntity> ObjectSet<TEntity>() 
                where TEntity : struct, EntityBase<TEntity>, IComparable

You are specifying that TEntity must be a struct and a reference type (EntityBase<> is a class, hence a reference type). These are mutually exclusive. What you probably want (it's hard to say without seeing CreateObjectSet) is:

public virtual IObjectSet<TEntity> ObjectSet<TEntity, T>() 
                where TEntity : EntityBase<T>
                where T : struct, IComparable

Note that this is just a guess based on your other code, but the main issue is that you are trying to limit a generic parameter to be both a struct and a class, and you need to fix that.

You do not specify what kind of error you are getting... Be sure that you are building targeting 4.0 Framework...