什么呢| =（单管等于）和放大器; =（单等于符号）的意思 [英] what does |= (single pipe equal) and &=(single ampersand equal) mean

问题描述

在下面几行：

//Folder.Attributes = FileAttributes.Directory | FileAttributes.Hidden | FileAttributes.System | FileAttributes.ReadOnly;
Folder.Attributes |= FileAttributes.Directory | FileAttributes.Hidden | FileAttributes.System | FileAttributes.ReadOnly;


Folder.Attributes |= ~FileAttributes.System;
Folder.Attributes &= ~FileAttributes.System;

什么呢 | = （单管相等）和＆安培; = （单个号相同）的意思是在c＃结果
我想删除系统属性以保持其他...

what does |= (single pipe equal) and &= (single ampersand equal) mean in c#
i want to remove system attribute with keeping the others...

在此先感谢

推荐答案

他们的复合分配的运营，翻译（非常松散）

They're compound assignment operators, translating (very loosely)

x |= y;

到

x = x | y;

和同为＆安培; 。有没有在关于隐式转换少数情况下多一点细节，目标变量只计算了一次，但基本上它的要点。

and the same for &. There's a bit more detail in a few cases regarding an implicit cast, and the target variable is only evaluated once, but that's basically the gist of it.

在非复合运营商而言， ＆安培; 是位与和 | 是一个位或。

In terms of the non-compound operators, & is a bitwise "AND" and | is a bitwise "OR".

编辑：在您希望这种情况下， Folder.Attributes＆安培; =〜FileAttributes.System 。要理解为什么：

In this case you want Folder.Attributes &= ~FileAttributes.System. To understand why:

• 〜FileAttributes.System 表示所有属性除了的系统（〜是一个按位NOT）


• ＆安培; 表示结果是所有操作数的两边发生的属性

• ~FileAttributes.System means "all attributes except System" (~ is a bitwise-NOT)
• & means "the result is all the attributes which occur on both sides of the operand"

所以基本上充当面膜 - 仅的保留中出现的那些属性（一切除了系统）。一般来说：

So it's basically acting as a mask - only retain those attributes which appear in ("everything except System"). In general:

• | = 将只添加的位目标


• ＆安培; = 仅会的删除的从目标位

• |= will only ever add bits to the target
• &= will only ever remove bits from the target

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