public class Customer
{
        public int CustomerId{get;set;}

        public string CustomerName{get;set;}

        public string Address{get;set;}
}

public interface ICustomerDataAccess
{
        bool Add(Customer customer);
}

//数据访问
public class CustomerDataAccess : ICustomerDataAccess
{
        public bool Add(Customer customer)
        {
                string sql = @"INSERT INTO dbo.Customer (CustomerName,Address) VALUES (CustomerName,@Address)";
               SqlParameter[] param = {
        new SqlParameter("@CustomerName",customer.CustomerName),
        new SqlParameter("@Address",customer.Address)
    };
    return SQLHelper.ExecuteNoQuery(sql,param);
        }
}

//业务逻辑
public class CustomerBusiness
{
       ICustomerDataAccess _customerDataAccess;
       
        //如果用这个构造函数实例化的话，就还是让CustomerBusiness依赖了具体的Customer实现(CustomerDataAccess)
        //所以用了一个带参数的构造函数注入
        //public CustomerBusiness()
        //{
    //   _customerDataAccess = new CustomerDataAccess();
        //}

        public CustomerBusiness(ICusomterDataAccess customerDataAccess)
        {
              _customerDataAccess = customerDataAccess;
        }

        public bool CreateCustomer(Customer customer)
        {
             return _customerDataAccess.Add(customer);
        }
}

protected void btnSave_Click(object sender,EventArgs e)
{
      //CustomerBusiness business = new CustomerBusiness(
      //就是这里该怎么调用CustomerBusiness呢？
}

public class CustomerDataAccessFactory {
    //里面有个获取实例的方法
     public static GetInstance() {
        //根据配置文件或写死 实例化哪个实体类
         ICusomterDataAccess customerDataAccess = new XXXXXXX();
        return customerDataAccess ;
    }
}

------解决方案--------------------

探讨

引用:

<add key="ICustomerDataAccess" value="ST.EIP.DataAccess.Interface.ICustomerDataAccess" />这样？


------解决方案--------------------
1.你的问题和解法无关，web里面其实不管，bil自己配对即可，web只管调用并不关心他们如何配对
2.有关注入，实现手段很多，我个人选择MEF，你只需要做好特性标记，让MEF自己去搜索组合他们就好了，MEF还是比较方便的，既不用修改代码，也不用修改配置文件。只是依靠元数据特性让MEF自己组合就好。

------解决方案--------------------
protected void btnSave_Click(object sender,EventArgs e)
{
     //CustomerBusiness business = new CustomerBusiness(
     //就是这里该怎么调用CustomerBusiness呢？
}
其实这个地方 和你在业务逻辑调用接口是一样的，都不应该 去 new ，依赖注入最基本特征就是不需要去new

但是你需要为CustomerBusiness business 这个对象指定一个 setter ,不知道你的spring 怎么配置的