blocks|key|2039102|text|如上所述，性能将受到影响。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2039103|另一个很大的好处是，你可以动态地加载程序集，执行属性操作，即使你可能没有查看要更改的范围，等等。|2039104|使用它的理由很多。如果你需要的话，这里是an+introduction。|offset|length|2039105|entityMap|0|LINK|mutability|MUTABLE|url|http://www.dotnet-guide.com/netreflection.html^0|0|0|K|F|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Q|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|R|8|@]|9|@$F|S|G|T|1|U]]|A|$]]|$1|H|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|I|$J|$5|K|L|M|A|$N|O]]]]

As mentioned above, performance will take a hit.

Another great advantage is that you can dynamically load assemblies, perform property manipulation even though you may not have the scope to see what to change, etc.

The reasons to use this are plenty. Here is <a href="http://www.dotnet-guide.com/netreflection.html" rel="noreferrer">an introduction</a> if you need.

blocks|key|1825327|text|反射只是在运行时调查对象的一种方式。如果你不需要这样做，你就不应该使用它。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1825328|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Reflection is just a way of investigating objects during run-time. You shouldn't use it if you don't need to do just that.

blocks|key|1825339|text|反射通常用在IoC容器中。假设你想注册每个以单词"Controller“结尾的具体类。反射使之成为小菜一碟。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1825340|在对类进行单元测试时，我还使用了反射来操作私有字段。|1825341|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

Reflection is commonly used in IoC containers. Let's say you want to register every concrete class the ends with the word "Controller". Reflection makes that a piece of cake.

I've also used reflection to manipulate private fields when unit testing classes.

blocks|key|2039139|text|我来自C%2B%2B，需要一些简单的类层次结构，我可以说is关键字是无价的！|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2039140|class+MenuItem+:+Item+{+}

foreach(Item+items+in+parent.ChildItems)+{
++++if+(item+is+MenuItem)+{+/*+handle+differently+*/+}
}|code-block|syntax|javascript|2039141|另外，反射是不是有点贵，顺便说一下？|2039142|entityMap^0|O|2|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|S|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|N|$]]

Coming from C++ and having needed some simple class hierarchies, I can say that the <code>is</code> keyword is invaluable!

<pre><code>class MenuItem : Item { }

foreach(Item items in parent.ChildItems) {
 if (item is MenuItem) { /* handle differently */ }
}
</code></pre>

P.S. Isn't reflection slightly expensive, btw?

blocks|key|1825361|text|例如，您可以使用反射来实现插件系统。你只需在一个文件夹中查找所有的DLL，并通过反射检查它们是否实现了某个插件接口。这是我使用反射的主要目的，但我也使用它实现了一个通用的自制对象序列化，其中性能不是最大的考虑因素。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1825362|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

You can use reflection to implement a system of plugins for example. You just look for all DLL's in a folder and through reflection check if they implement a certain plugin interface. This is the main purpose for which I used reflection, but I also used it to implement a generic home-brew object serialization, where performance was not the greatest concern.

blocks|key|1825370|text|非常有用的XmlSerialization类依赖于反射。您不必自己处理反射来使用序列化，序列化类调用反射本身。但是，用属性标记代码有助于指导如何序列化对象。序列化类在运行时使用反射来读取这些属性。最后，这个过程看起来很神奇，在应用程序中只需要很少的几行显式编码；正是反射使这种便利性成为可能。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1825371|XmlSerialization本身很棒，不仅因为它是从应用程序创建数据文件的一种非常方便的方法，而且还是一种为调试目的生成程序内部数据模型的人类可读记录的一种非常简单的方法。|1825372|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

The very useful XmlSerialization class relies on reflection. You don't have to deal with reflection yourself to use serialization, the serialization classes invoke reflection themselves. But it helps to tag your code with Attributes that guide how objects are serialized. The serialization classes use reflection at runtime to read those attributes. In the end, the process seems almost magical, requiring very few lines of explicit coding in a application; it's reflection that makes that convenience possible. 

XmlSerialization itself is awesome not only because it is a very convenient way to create data files from an application, it's also a very easy means of generating human readable records of a program's internal data model for debugging purposes.

Is it definitely a good practice to use it? 

What are some possible situations in a project that need reflection?

Why is the use of reflection in .NET recommended?

单元测试

容器

使用它确实是一种好的实践吗？项目中可能存在哪些需要反思的情况？

问为什么推荐在.NET中使用反射？
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