它告诉NGEN，这是OK内联它的应用方法，即使在不同的装配。

It tells NGen that it is OK to inline the method it's applied to even in a different assembly.

例如：

• String.Equals 的 [TargetedPatchingOptOut]
• 您编写一个程序，调用 String.Equals
• 您对这个项目的最高性能运行 NGEN
• NGEN将内联 String.Equals 通话，与实际code的方法替换方法调用指令。
  方法调用（略）贵，所以这是一个性能提升对于经常调用的方法。

• String.Equals has [TargetedPatchingOptOut]
• You write a program that calls String.Equals
• You run NGen on this program for maximum performance
• NGen will inline the String.Equals call, replacing the method call instruction with the actual code in the method.
  Method calls are (slightly) expensive, so this is a performance boost for frequently-called methods.

不过，如果微软发现在 String.Equals 安全漏洞，他们不能只更新 mscorlib.dll中，因为这会不会影响你刚才NGen'd大会。 （因为它有没有引用原机code String.Equals ）。
我认为，如果这是实际发生的，此安全更新将清零NGEN店。

However, if Microsoft finds a security hole in String.Equals, they cannot just update mscorlib.dll, because that won't affect the assembly that you just NGen'd. (Since it has raw machine code without referencing String.Equals).
I assume that if that were to actually happen, the security update would clear the NGen store.

请注意，此属性仅在.NET框架组件是有用的。你不需要在你自己的。你可以找到这里的更多信息： http://***.com/a/14982340/631802

Note that this attribute is only useful in the .NET Framework assemblies. You don't need it in your own. You can find more information about that here: http://***.com/a/14982340/631802