namespace demo.BLL
{
public class CategoryBLL
{
private static readonly ICategory dal = demo.DALFactory.DataAccess.CreateCategory();
public DataSet GetCategories()
{
return dal.GetCategories();
} }
}
namespace demo.DALFactory
{
public class DataAccess
{
private DataAccess() { }
public static demo.DAL.ICategory CreateCategory()
{
return (demo.DAL.ICategory)Assembly.Load("demo.DAL").CreateInstance("demo.DAL.Category");
}
}
}
namespace demo.DAL
{
public interface ICategory
{
DataSet GetCategories();
}
public class CategoryDAL : ICategory
{
public DataSet GetCategories() {}
}
}
From1
private CategoryBLL cBll = new CategoryBLL();
执行后这行报错：“demo.BLL.CategoryBLL”的类型初始值设定项引发异常。
这是什么问题？
