问题描述
我不明白为什么这段代码不起作用.
I don't understand why this code does not work.
foreach (DataRow dataRow in dataTable.Rows)
{
if (true)
{
dataRow.Delete();
}
}
推荐答案
即使 DataRow.Delete 不会修改集合的状态，Microsoft 文档 指出在迭代收藏:
Even though DataRow.Delete doesn't modify the state of the collection, Microsoft documentation states that you shouldn't call it while iterating over the collection:
在遍历 DataRowCollection 对象时，不应在 foreach 循环中调用 Delete 或 Remove.Delete 或 Remove 修改集合的状态.
Neither Delete nor Remove should be called in a foreach loop while iterating through a DataRowCollection object. Delete nor Remove modify the state of the collection.
最好的解决方案通常是为要删除的项目创建一个单独的集合(例如，List<DataRow>)，然后在之后删除它们完成迭代.
The best solution is usually to create a separate collection (e.g. a List<DataRow>) of items you want to remove, and then remove them after you've finished iterating.
这也是您想要从集合中删除项目的情况的解决方案，因为 .NET 中的大多数集合不允许您在迭代时更改集合的内容.
This is also the solution for situations where you want to remove items from a collection, as most collections in .NET don't allow you to change the contents of the collection while you're iterating over it.
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