两种实现模式，还是选择2，少一层继承。

 public class Model


[code]{

}

public interface IRepository<TEntity>

{

/// <summary>

/// Gets entity by key.

/// </summary>

/// <typeparam name="TEntity">The type of the entity.</typeparam>

/// <param name="keyValue">The key value.</param>

/// <returns></returns>

TEntity GetByKey(object keyValue);

}

public interface IRepository

{

/// <summary>

/// Gets entity by key.

/// </summary>

/// <typeparam name="TEntity">The type of the entity.</typeparam>

/// <param name="keyValue">The key value.</param>

/// <returns></returns>

TEntity GetByKey<TEntity>(object keyValue) where TEntity : class;

}

public class BaseRepository   : IRepository

{

public TEntity GetByKey<TEntity>(object keyValue) where TEntity : class

{

throw new NotImplementedException();

}

}

public class BaseRepository<T> : BaseRepository, IRepository<T> where T : class

{

public T GetByKey(object keyValue)

{

return this.GetByKey<T>(keyValue);

}

}

public class BaseRepository2<T> : IRepository, IRepository<T> where T : class

{

public T GetByKey(object keyValue)

{

return this.GetByKey<T>(keyValue);

}

public TEntity GetByKey<TEntity>(object keyValue) where TEntity : class

{

throw new NotImplementedException();

}

}

public interface IBiz

{

void Get();

}

class bbb : BaseRepository<Object>, IBiz

{

public void Get()

{

this.GetByKey(1);

this.GetByKey<Model>(1);

}

}

[/code]

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