我使用 EF 4。拥有此代码来测试我的模型的功能。
using (var context = new CamelotDB())
{
Console.WriteLine("Starting User Repository Testing{0}",Environment.NewLine);
Console.WriteLine("Creating Test User");
DomainEntity userToAdd = new User()
{
EntityName = "Test User",
EntityType = DomainEntity.eEntityType.User,
Username = "TestUser",
Password = "123",
Email = "TestUser@Test.org",
FirstName = "Test",
LastName = "User",
Phone = "123456789",
EntityParentID = null,
};
Console.WriteLine("Saving user to database...");
userToAdd = context.DomainEntities.Add(userToAdd);
context.SaveChanges();
Console.WriteLine("Fetching user from database...");
int userID = userToAdd.EntityID;
DomainEntity userToDelete = context.DomainEntities.Find(userID);
Console.WriteLine("Removing the user...");
context.DomainEntities.Remove(userToDelete);
context.SaveChanges();
}
用户成功添加到数据库，我取回用户 ID。当我尝试使用该Find()方法时
DomainEntity userToDelete = context.DomainEntities.Find(userID);
我收到以下错误：值不能为空。参数名称键
我事件试图调用以下内容：
DomainEntity userToDelete = context.DomainEntities.Find(2);
知道用户 ID 2 存在于数据库中，但仍然得到相同的异常。