private CustomerData logonCustomerData;
logonCustomerData = (CustomerData) Customer;其中CustomerData的类型是DataSet,
logonCustomerData = (CustomerData) Customer;和
logonCustomerData = new CustomerData(Customer)有什么区别呢?
logonCustomerData = (CustomerData) Customer;其中CustomerData的类型是DataSet,
logonCustomerData = (CustomerData) Customer;和
logonCustomerData = new CustomerData(Customer)有什么区别呢?
前者只是引用了 Customer, 并作了必要的转换,并没有在内存堆生成新的DataSet对象而后者是新建了一个CustomerData 对象
new是创建了一个新的CustomerData实例!!!
强制(显式)类型转换,也就是将Customer 转换成 CustomerData类型,赋给logonCustomerDatalogonCustomerData = new CustomerData(Customer)
这个语句通过Customer参数创建一个CustomerData实例。
logonCustomerData = (CustomerData) Customer;=========》编译器最后还是要转到这个logonCustomerData = new CustomerData(Customer)