c＃

Question

我有一个我想删除的父母。它看起来像这样：

-Parent
 - Child 1
   -Subchild 1
   -Subchild 2

当我删除父级时，我还要删除Subchild。这是我的代码：

public void DeleteMenu(int id)
    {
        var item = this.db.Menus.Single(x => x.Id == id);

        //DELETE FOREIGN KEYS
        //MenuLanguageSet
        var languages = from listLanguages in this.db.MenuLanguageSet
                        where listLanguages.idMenu == id
                        select listLanguages;

        foreach (var itemLanguages in languages)
        {
            this.db.MenuLanguageSet.Remove(itemLanguages);
        }

        //Accesses
        var accesses = from listAccesses in this.db.Accesses
                        where listAccesses.menuId == id
                        select listAccesses;



        foreach (var itemAccesses in accesses)
        {
            this.db.Accesses.Remove(itemAccesses);    
        }

        //DELETE CHILD
        //Menus
        var menusChild = from listmenus in this.db.Menus
                        where listmenus.parentId == id
                        select listmenus;

        foreach (var child in menusChild)
        {
            DeleteMenu(child.Id);
        }


        //delete parent
        this.db.Menus.Remove(item);
        this.db.SaveChanges();


    }

这不起作用，我不知道为什么。我不知道如何制作循环。

Answer 1

知道了！

这是我的最终代码：

    public void DeleteMenu(int id)
    {
        this.RecursiveDeleteMenu(id);
        this.db.SaveChanges();


    }
    public void RecursiveDeleteMenu(int id)
    {
        var item = this.db.Menus.Single(x => x.Id == id);

        //DELETE FOREIGN KEYS
        //MenuLanguageSet
        var languages = from listLanguages in this.db.MenuLanguageSet
                        where listLanguages.idMenu == id
                        select listLanguages;

        foreach (var itemLanguages in languages)
        {
            this.db.MenuLanguageSet.Remove(itemLanguages);
        }

        //Accesses
        var accesses = from listAccesses in this.db.Accesses
                       where listAccesses.menuId == id
                       select listAccesses;



        foreach (var itemAccesses in accesses)
        {
            this.db.Accesses.Remove(itemAccesses);
        }

        //DELETE CHILD
        //Menus
        var menusChild = from listmenus in this.db.Menus
                         where listmenus.parentId == id
                         select listmenus;

        foreach (var child in menusChild)
        {
            RecursiveDeleteMenu(child.Id);
        }


        //delete parent
        this.db.Menus.Remove(item);
    }

我收到错误New transaction is not allowed because there are other threads running in the session，因为this.db.SaveChanges()处于循环中。

谢谢大家！