集合已修改枚举操作可能无法执行 [英] collection was modified enumeration operation may not execute

问题描述

public void DeleteAllListItem(ListBox LstDelete, string path)
      {
          ftp = new FTPOperations();
          foreach (ListItem i in LstDelete.Items)
          {
              ftp.DeleteFTP(path + i.Text);
              LstDelete.Items.Remove(i.Text);

          }
      }

错误:集合被修改，枚举操作可能无法执行

Error:collection was modified enumeration operation may not execute

推荐答案

错误消息非常明确，而且很明确:您已更改了foreach循环为使用，结果无法确定它在做什么.枚举集合时，您不能添加，删除或以其他方式修改集合.
正常的方法是:
1)建立要删除的项目的列表，然后在循环的最后将其删除.
或
2)改为使用for循环.

The error message is pretty explicit, and pretty clear: you have changed the collection that the foreach loop is using, and as a result it cannot be sure what it is doing. You cannot add to, delete from, or otherwise modify a collection while it is being enumerated.
The normal ways to do it are:
1) Build a list of items to remove in a separate list, then delete them at the end of the loop.
or
2) use a for loop instead.

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