square0297

说明：  编写可串行化类时，MFC用你指定的模式号制定一个粗略的版本控制方式。在向档案写数据时，MFC用模式标记该类的实例；而在读回数据时，MFC将档案中的记录的模式号和应用程序中使用着的 该类对象的模式号做比较，如果两模式号不匹配，则MFC发送一个CArchiveException，其m_cause 等于CArchiveException::badSchema。没有得到处理的该类异常会促使MFC显示一个对话框，提示 “非预期的文件格式”。如果每次修改对象的串行化存储格式时都能做到增加模式号，那么就不怕 这种无心的操作—试图把磁盘中存的老版本对象读入内存里的新版本对象了。 [代码性质] VC完整应用程序代码 [代码作者] 阿豪(kof) [文件大小] 369K
(prepared Serializable category, the MFC with you specify the mode of development of a rough version control mode. To write data files, the MFC model with markings such examples; In reading back the data, MFC will file the record of the model and application procedures with the use of such objects, the model used for comparison, if the two patterns do not match, and then send a CArchiveException MFC, equivalent to m_cause CArchiveException : : badSchema. Not to be addressed such abnormal prompted MFC will show a dialog box, suggesting that "unintended file format." If every amendment targets of serial storage format can achieve the increase mode, so it is not afraid of such inadvertent operation-tried to deposit disk version of the old object is read into memory's new version )