EF架构获取数据时报错：The ObjectContext instance has been disposed and can no longer be used for operations that require a connection. Do you want to correct the value?

场景：

EF底层，获取完主表，点击按钮，添加主表，字表内容时，报以上错误

解决方案：

在EF文件的空白处右键--属性，将“应用延迟加载”，改为False