你可以用两种方法去除

var output = from x in authorsList
             where x.firstname != "Bob"
             select x;

or

var authors = from x in authorsList
              where x.firstname == "Bob"
              select x;

var output = from x in authorsList
             where !authors.Contains(x) 
             select x;

我也有同样的问题，如果你想根据你的where条件简单输出，那么第一个解决方案更好。

简单的解决方案:

static void Main()
{
    List<string> myList = new List<string> { "Jason", "Bob", "Frank", "Bob" };
    myList.RemoveAll(x => x == "Bob");

    foreach (string s in myList)
    {
        //
    }
}

如果你真的需要删除项目，那么Except()怎么办? 你可以基于一个新的列表删除，或者通过嵌套Linq。

var authorsList = new List<Author>()
{
    new Author{ Firstname = "Bob", Lastname = "Smith" },
    new Author{ Firstname = "Fred", Lastname = "Jones" },
    new Author{ Firstname = "Brian", Lastname = "Brains" },
    new Author{ Firstname = "Billy", Lastname = "TheKid" }
};

var authors = authorsList.Where(a => a.Firstname == "Bob");
authorsList = authorsList.Except(authors).ToList();
authorsList = authorsList.Except(authorsList.Where(a=>a.Firstname=="Billy")).ToList();

嗯，从一开始就把他们排除在外会更容易:

authorsList = authorsList.Where(x => x.FirstName != "Bob").ToList();

但是，这只会改变authorsList的值，而不是从以前的集合中删除author。或者，你可以使用RemoveAll:

authorsList.RemoveAll(x => x.FirstName == "Bob");

如果你真的需要基于另一个集合来做，我会使用HashSet, RemoveAll和Contains:

var setToRemove = new HashSet<Author>(authors);
authorsList.RemoveAll(x => setToRemove.Contains(x));

为了保持代码流畅(如果代码优化不是关键)，你需要对列表做一些进一步的操作:

authorsList = authorsList.Where(x => x.FirstName != "Bob").<do_some_further_Linq>;

or

authorsList = authorsList.Where(x => !setToRemove.Contains(x)).<do_some_further_Linq>;

你可以用两种方法去除

var output = from x in authorsList
             where x.firstname != "Bob"
             select x;

or

var authors = from x in authorsList
              where x.firstname == "Bob"
              select x;

var output = from x in authorsList
             where !authors.Contains(x) 
             select x;

我也有同样的问题，如果你想根据你的where条件简单输出，那么第一个解决方案更好。