处理 streamreader 会关闭流吗?

问题描述

我正在向要写入的方法发送流，并且在这些方法中我使用的是二进制读取器/写入器.当读取器/写入器被处理时，无论是通过 using 还是没有被引用，流是否也关闭了??

I am sending a stream to methods to write on, and in those methods I am using a binary reader/wrtier. When the reader/writer gets disposed, either by using or just when it is not referenced, is the stream closed as well??

我会发送一个 BinaryReader/Writer，但我也在使用 StreamReader(也许我应该解决这个问题.我只将它用于 GetLine 和 ReadLine).如果每次关闭写入器/读取器时它都关闭流，这将非常麻烦.

I would send a BinaryReader/Writer, but I am using a StreamReader too (maybe I should go around that. I am only using that for GetLine and ReadLine). This is quite troublesome if it closes the stream each time a writer/reader gets closed.

推荐答案

Yes, StreamReader, StreamWriter, BinaryReader and BinaryWriter 当您对它们调用 Dispose 时，所有它们都会关闭/处理它们的底层流.如果读取器/写入器只是垃圾收集，它们不会处理流-您应该始终处理读取器/写入器，最好使用 using 语句.(事实上??，这些类都没有终结器，也不应该有.)

Yes, StreamReader, StreamWriter, BinaryReader and BinaryWriter all close/dispose their underlying streams when you call Dispose on them. They don't dispose of the stream if the reader/writer is just garbage collected though - you should always dispose of the reader/writer, preferrably with a using statement. (In fact, none of these classes have finalizers, nor should they have.)

就我个人而言，我也更喜欢对流使用 using 语句.您可以非常整齐地嵌套 using 不带大括号的语句:

Personally I prefer to have a using statement for the stream as well. You can nest using statements without braces quite neatly:

using (Stream stream = ...)
using (StreamReader reader = new StreamReader(stream, Encoding.Whatever))
{
}

即使流的 using 语句有些多余(除非 StreamReader 构造函数抛出异常)我认为这是最佳实践，因为如果你摆脱了StreamReader 并在以后直接使用流，您已经拥有正确的处理语义.

Even though the using statement for the stream is somewhat redundant (unless the StreamReader constructor throws an exception) I consider it best practice as then if you get rid of the StreamReader and just use the stream directly at a later date, you'll already have the right disposal semantics.