摘要：Adding Validation to our Album FormsWe’ll use the following Data Annotation attributes:Required – Indicates that the property is a required fieldDisplayName – Defines the text we want used on form fields and validation messagesStringLength – Defines a maximum length for a string fieldRange – Gives a 阅读全文

摘要：问题描述Store update, insert, or delete statement affected an unexpected number of rows ({0}). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries.存储区更新、插入或删除语句影响到了意外的行数({0})。实体在加载后可能被修改或删除。刷新 ObjectStateManager 项。原因分析使用 Entity Framework 更新记录时出现上述异，原 阅读全文