集合被修改;枚举操作可能无法执行的ArrayList

问题描述:

我想从的ArrayList 删除一个项目,我得到这个异​​常:结果
集合已修改;枚举操作可能无法执行。

I'm trying to remove an item from an ArrayList and I get this Exception:
Collection was modified; enumeration operation may not execute.

任何想法?

正在拆除中的项的foreach ,是吗?简单地说,你不能。有几个常用的选项这里:

You are removing the item during a foreach, yes? Simply, you can't. There are a few common options here:


  • 使用列表< T> removeall过以predicate

  • 向后遍历通过索引,删除匹配的项目

  • use List<T> and RemoveAll with a predicate
  • iterate backwards by index, removing matching items

for(int i = list.Count - 1; i >= 0; i--) {
    if({some test}) list.RemoveAt(i);
}


  • 使用的foreach ,并把匹配的项目进入第二个列表;现在列举的第二个列表,从第一个删除这些项目(如果你明白我的意思)

  • use foreach, and put matching items into a second list; now enumerate the second list and remove those items from the first (if you see what I mean)