public static void AttachAndMovePosts(Blog efBlog, List <Post> Posts)
{
using (var context = new AnotherBlogContext())
{
try
{
context.Configuration.AutoDetectChangesEnabled = false;
context.Blogs.Attach(efBlog);
Posts.ForEach(p =>
{
context.Posts.Attach(p);
if (p.Title.StartsWith("Entity Framework:"))
{
context.Entry(p).Property(p2 => p2.Title).CurrentValue = p.Title.Replace("Entity Framework:", "EF:");
context.Entry(p).Reference(p2 => p2.Blog).CurrentValue = efBlog;
}
});
context.SaveChanges();
}
finally
{
context.Configuration.AutoDetectChangesEnabled = true;
}
}
}
public static void T5D4()
{
using (var context = new AnotherBlogContext())
{
var post = context.Posts.First(p => p.BlogId == 1);
post.BlogId = 2;
var blog2 = context.Blogs.Find(2);
}
}
public static void T5D1()
{
using (var context = new AnotherBlogContext())
{
var post = context.Posts.Single(p => p.Title == "My First Post");
post.Title = "My Best Post";
context.SaveChanges();
}
}
public static void T5D3()
{
using (var context = new AnotherBlogContext())
{
context.Blogs.Load();
var post = context.Posts.Single(p => p.Title == "My First Post");
Console.WriteLine(context.Entry(post).State);
//或者
var entry = context.Entry <Post>(post);
Console.WriteLine(entry.State);
}
}
public static void AddPosts(List <Post> Posts)
{
using (var context = new AnotherBlogContext())
{
try
{
context.Configuration.AutoDetectChangesEnabled = false;
Posts.ForEach(p => context.Posts.Add(p));
}
finally
{
context.Configuration.AutoDetectChangesEnabled = true;
}
context.SaveChanges();
}
}
