C# 字符串比较：CurrentCultureIgnoreCase 和 InvariantCultureIgnoreCase 之间的区别
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/417954/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
C# String comparisons: Difference between CurrentCultureIgnoreCase and InvariantCultureIgnoreCase
提问by Dan Esparza
When doing a string comparison in C#, what is the difference between doing a
在 C# 中进行字符串比较时，与执行字符串比较有什么区别
string test = "testvalue";
test.Equals("TESTVALUE", StringComparison.CurrentCultureIgnoreCase);
and
和
string test = "testvalue";
test.Equals("TESTVALUE", StringComparison.InvariantCultureIgnoreCase);
... and is it important to include that extra parameter, anyway?
......无论如何，包含那个额外的参数很重要吗？
采纳答案by Michael Burr
Microsoft gives some decent guidance for when to use the InvariantCultureproperty:
微软为何时使用该InvariantCulture属性提供了一些不错的指导：
MSDN: CultureInfo.InvariantCulture Property
MSDN：CultureInfo.InvariantCulture 属性
... an application should use the invariant culture only for processes that require culture-independent results, such as formatting and parsing data that is persisted to a file. In other cases, it produces results that might be linguistically incorrect or culturally inappropriate.
Security Considerations
If a security decision will be made based on the result of a string comparison or case change, your application should use an ordinal comparison that ignores case instead of using InvariantCulture. [...]
String Operations
If your application needs to perform a culture-sensitive string operation that is not affected by the value of CurrentCulture, it should use a method that accepts a CultureInfo parameter. [...]
Persisting Data
The InvariantCulture property is useful for storing data that will not be displayed directly to users. Storing data in a culture-independent format guarantees a known format that does not change. When users from different cultures access the data, it can be formatted appropriately based on specific user. [...]
...应用程序应仅将不变区域性用于需要与区域性无关的结果的进程，例如格式化和解析持久化到文件的数据。在其他情况下，它产生的结果可能在语言上不正确或在文化上不合适。
安全注意事项
如果将根据字符串比较或大小写更改的结果做出安全决策，您的应用程序应使用忽略大小写的序数比较，而不是使用 InvariantCulture。[...]
字符串操作
如果您的应用程序需要执行不受 CurrentCulture 值影响的区分区域性的字符串操作，则应使用接受 CultureInfo 参数的方法。[...]
持久化数据
InvariantCulture 属性对于存储不会直接向用户显示的数据很有用。以与文化无关的格式存储数据可保证已知格式不会改变。当来自不同文化的用户访问数据时，可以根据特定用户对其进行适当的格式化。[...]
回答by Jon Skeet
The other posts have given good advice, but I thought it might be nice to show an example of where it definitely makes a difference:
其他帖子给出了很好的建议，但我认为展示一个绝对有影响的例子可能会很好：
using System;
using System.Globalization;
using System.Threading;
class Test
{
static void Main()
{
CultureInfo turkish = CultureInfo.CreateSpecificCulture("tr");
Thread.CurrentThread.CurrentCulture = turkish;
// In Turkey, "i" does odd things
string lower = "i";
string upper = "I";
Console.WriteLine(lower.Equals(upper,
StringComparison.CurrentCultureIgnoreCase));
Console.WriteLine(lower.Equals(upper,
StringComparison.InvariantCultureIgnoreCase));
}
}
(There are no doubt many other cases - this was just the first one I thought of.)
（毫无疑问，还有许多其他情况——这只是我想到的第一个。）
