EF6 如何判断DataContext有修改,以及如何放弃修改
如何判断DataContext有修改:
EF6的
using (var db = new Model1()) { if (db.ChangeTracker.HasChanges()) { Console.WriteLine("Something has changed"); } }
EF5中:
public bool HasUnsavedChanges() { return this.ChangeTracker.Entries().Any(e => e.State == EntityState.Added || e.State == EntityState.Modified || e.State == EntityState.Deleted); }
EF4中为:
public Boolean HasUnsavedChanges() { return (this.ObjectContext().ObjectStateManager.GetObjectStateEntries(EntityState.Added | EntityState.Modified | EntityState.Deleted).Any()); }
DataContext如何放弃修改的建议:
this is not supposed way to use context. Context is unit of work - do changes you really want to do and then save them. If you find that you don't want to save changes dispose the context and create a new one. The best practice is using context for one single logical operation. Sharing context or using static context is a bad practice and because of that there is no build in method to "reset" context - you must do it yourselves by exploring ObjectStateManager and reverting all changes (it can be quite complex task).