实体框架4-删除对象

Question

I have 3 Tables in my DataBase

CmsMasterPages
CmsMasterPagesAdvSlots (Pure Juction Table)
CmsAdvSlots

Here a Picture of my EDM:

I need find out all objects CmsAdvSlot connected with a CmsMasterPage (it is working in my code posted belove), and DELETE the result (CmsAdvSlot) from the DataBase.

My Problem is I am not able to DELETE this Objects when I found theme.

Error: The object cannot be deleted because it was not found in the ObjectStateManager. 

---

        int findMasterPageId = Convert.ToInt32(uxMasterPagesListSelector.SelectedValue);
        CmsMasterPage myMasterPage = context.CmsMasterPages.FirstOrDefault(x => x.MasterPageId == findMasterPageId);
        var resultAdvSlots = myMasterPage.CmsAdvSlots;
        // It is working until here
        foreach (var toDeleteAdv in resultAdvSlots)
        {
            context.DeleteObject(myMasterPage.CmsAdvSlots.Any()); // ERORR HERE!!
            context.SaveChanges();
        }

---

Any idea how to solve it? Thanks for your time! :-)

Answer 1

Try this:

while (myMasterPage.CmsAdvSlots.Count > 0)
{
  var slot = myMasterPage.CmsAdvSlots.First();
  myMasterPage.CmsAdvSlots.Remove(slot); // This is required only in some scenarios - it depends on type of entities you are using.
  context.DeleteObject(slot);
}

context.SaveChanges();

Answer 2

.Any() returns a boolean. Use .First() instead, .First() will in your case return the first CmsAdvSlot .

If you want to remove all CmsAdvSlot I would follow @Ladislav Mrnka's example.

Answer 3

In context.DeleteObject(myMasterPage.CmsAdvSlots.Any());
myMasterPage.CmsAdvSlots.Any() should return you a bool You should try using myMasterPage.CmsAdvSlots.First() instead!