StreamWriter.Write（bool值）---文件中应该有多少位/字节？ [英] StreamWriter.Write(bool value) --- How many bits/bytes should end up in the file?

问题描述

我需要写出从其他进程收到的位。这些

是布尔值。我需要每个字节有8位。我知道我

可以将这些位写成char'，每个字节使用一位，但是

将是空间效率低的。

我正在使用od（八进制转储）查看通过调用

..Write（true）和.Write（false）生成的文件，看起来它写出来了4个字节
每个布尔值
。


我缺少什么？在什么世界中需要4个字节来表示

布尔值？是否有某种对齐问题导致

这个？


感谢!!!!


John

解决方案

John< jo ******** @ hotmail.com>写道：

我需要写出从另一个进程收到的位。这些是布尔值。我需要每个字节有8位。我知道我可以使用每个字节一位来将这些位写成char'，但是
将是空间效率低的。

我正在使用od（八进制转储）查看通过调用
.Write（true）和.Write（false）生成的文件，它看起来像每个布尔值写出4个字节
我错过了什么？在什么世界中需要4个字节来表示
布尔值？是否存在导致这种问题的某种对齐问题？

StreamWriters用于* text *数据，而不是二进制数据，这就是它

听起来像你想要的。


StreamWriter.Write（bool）写出一个

布尔值的* text *表示，记录下来。


-

Jon Skeet - < sk *** @ pobox.com>
http://www.pobox.com/~skeet

如果回复请不要给我发邮件

占用4个字节，因为这是bool的内存布局。根据流的工作原理，他们能做的最好的是每个bool 1个字节如果你使用

写（bool）Read（bool）。但是，你可以通过一组

方法做得更好，这些方法采用一系列bool并将其转换为一系列字节

，具体取决于你发出的bool数量。

-

贾斯汀罗杰斯

DigiTec网络顾问有限责任公司。

博客： http://weblogs.asp.net/justin_rogers


"约翰" <乔******** @ hotmail.com>在消息中写道

news：d8 ************************** @ posting.google.c om ...

我需要写出从其他进程收到的位。这些是布尔值。我需要每个字节有8位。我知道我可以使用每个字节一位来将这些位写成char'，但是
将是空间效率低的。

我正在使用od（八进制转储）查看通过调用
.Write（true）和.Write（false）生成的文件，它看起来像每个布尔值写出4个字节
我错过了什么？在什么世界中需要4个字节来表示
布尔值？是否存在导致这种情况的某种对齐问题？

感谢!!!!

约翰

Justin Rogers< Ju **** @ games4dotnet.com>写道：

需要4个字节，因为这是bool的内存布局。

不，它需要4个字节，因为它是写出真实 - 如果传入false，则需要5

字节（假设编码使用一个字节
每个字符
当然）。


-

Jon Skeet - < sk *** @ pobox.com>
http://www.pobox.com/~skeet

如果回复该群组，请不要给我发邮件

Hi,

I need to write out bits that I receive from another process. These
are boolean values. I need there to be 8 bits in every byte. I know I
could write these bits out as char''s using one bit per byte, but that
would be space-inefficient.

I''m using od (octal dump) to look at a file produced by calling
..Write(true) and .Write(false) and it looks like it writes out 4 bytes
per boolean value.

What am I missing? In what world does it take 4 bytes to represent a
boolean value? Is there some sort of alignment issue that''s causing
this?

THANKS!!!!

John

解决方案

John <jo********@hotmail.com> wrote:

I need to write out bits that I receive from another process. These
are boolean values. I need there to be 8 bits in every byte. I know I
could write these bits out as char''s using one bit per byte, but that
would be space-inefficient.

I''m using od (octal dump) to look at a file produced by calling
.Write(true) and .Write(false) and it looks like it writes out 4 bytes
per boolean value.

What am I missing? In what world does it take 4 bytes to represent a
boolean value? Is there some sort of alignment issue that''s causing
this?

StreamWriters are for *text* data, not binary data, which is what it
sounds like you want.

StreamWriter.Write(bool) writes out the *text* representation of a
boolean, as documented.

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

Takes 4 bytes since that is the memory layout of a bool. Based on the way
the streams work, the best they could do is 1 byte per bool if you used
Write(bool) Read(bool). However, you could do better by having a set of
methods that took an array of bools and converted that into a series of bytes
depending on how many bools you were emitting.
--
Justin Rogers
DigiTec Web Consultants, LLC.
Blog: http://weblogs.asp.net/justin_rogers

"John" <jo********@hotmail.com> wrote in message
news:d8**************************@posting.google.c om...

Hi,

I need to write out bits that I receive from another process. These
are boolean values. I need there to be 8 bits in every byte. I know I
could write these bits out as char''s using one bit per byte, but that
would be space-inefficient.

I''m using od (octal dump) to look at a file produced by calling
.Write(true) and .Write(false) and it looks like it writes out 4 bytes
per boolean value.

What am I missing? In what world does it take 4 bytes to represent a
boolean value? Is there some sort of alignment issue that''s causing
this?

THANKS!!!!

John

Justin Rogers <Ju****@games4dotnet.com> wrote:

Takes 4 bytes since that is the memory layout of a bool.

Nope, it takes 4 bytes since it''s writing out "True" - it would take 5
bytes if you passed in false (assuming an encoding which uses one byte
per character, of course).

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

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