blocks|key|881492|text|不，无法覆盖现有属性。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|881493|属性是附加到对象(程序集、类、方法、变量等)的元数据，因此它们始终保持这种连接。|881494|如果您想在基类中给出一个默认的“行为”，并在一些派生类中覆盖它，您必须检查GetCustomAttributes()返回的所有属性，以便只使用派生最多的属性(列表中的第一个)。|offset|length|style|CODE|881495|entityMap^0|0|0|11|L|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|N|8|@$F|O|G|P|H|I]]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|K|$]]

No, it's not possible to override the existing attribute.

Attributes are metadata attached to an object (assembly, class, method, variable and so on) so they always keep this connection.

If you want to give a default "behavior" in the base class and override it in some derived classes you have to check all the attributes returned by <code>GetCustomAttributes()</code> to use only the most derived one (the first in the list).

blocks|key|2519949|text|使用[AttributeUsage(Inherited=false)]防止派生类继承该属性。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2519950|entityMap^0|2|X|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

use <code>[AttributeUsage(Inherited=false)]</code> to prevent the attribute being inherited by the derived class.

blocks|key|881533|text|我认为这是可以通过以下方式实现的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|881534|1.使用TypeDescriptor|881535|在您的CustomDesignerAttribute中覆盖TypeId|offset|length|style|CODE|881536|public+override+object+TypeId
{
+++++get
+++++{
+++++++++return+Key.GetHashCode();
++++++}
+}|code-block|syntax|javascript|881537|TypeId的基本实现只使用属性类型，因此不涉及任何参数。|881538|然后你就可以使用TypeDescriptor.GetAttributes(typeof(ChildClass)).OfType<CustomDesignerAttribute>()了|881539|TypeDescriptor+(与GetType().GetCustomAttributes相反)仅根据相同的TypeId返回一个属性。我测试了它，它是与返回的TypeId最匹配的派生属性。|881540|因此，如果您的TypeId表示属性的键，那么当使用TypeDescriptor获取属性时，您可以在派生类上覆盖它！注意，仍然可以有多个属性，只要它们的键不同即可。|881541|注意:+TypeDescriptor还会查找动态添加的属性(在运行时添加)|881542|2.使用删除属性|881543|您可以在您的CustomDesignerAttribute中添加一个公共bool+Remove+{+get;+set;+}。可以在派生类中将其设置为true，同时将其他参数设置为与要移除的基类属性相同的参数。然后向派生类添加另一个具有相同键但需要的值的属性。在获取属性时，您必须以一种聪明的方式计算Remove属性。无论是像1)中那样使用TypeDescriptor与TypeId一起使用，例如返回Key.HashCode()+%2B+Value.GetHashCode()或使用GetType().GetCustomAttributes，在这两种方式下，你都必须遍历属性列表和过滤器。您必须知道这些列表的顺序是什么，如果大多数派生类型先出现，还是相反。|881544|entityMap^0|0|0|3|N|T|6|0|0|0|6|0|8|2A|0|0|E|H|T|1J|6|28|6|0|7|6|P|E|0|0|0|6|N|10|P|22|4|54|6|5J|10|6M|T|0^^$0|@$1|2|3|4|5|6|7|14|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|15|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|16|8|@$F|17|G|18|H|I]|$F|19|G|1A|H|I]]|9|@]|A|$]]|$1|J|3|K|5|L|7|1B|8|@]|9|@]|A|$M|N]]|$1|O|3|P|5|6|7|1C|8|@$F|1D|G|1E|H|I]]|9|@]|A|$]]|$1|Q|3|R|5|6|7|1F|8|@$F|1G|G|1H|H|I]]|9|@]|A|$]]|$1|S|3|T|5|6|7|1I|8|@$F|1J|G|1K|H|I]|$F|1L|G|1M|H|I]|$F|1N|G|1O|H|I]|$F|1P|G|1Q|H|I]]|9|@]|A|$]]|$1|U|3|V|5|6|7|1R|8|@$F|1S|G|1T|H|I]|$F|1U|G|1V|H|I]]|9|@]|A|$]]|$1|W|3|X|5|6|7|1W|8|@]|9|@]|A|$]]|$1|Y|3|Z|5|6|7|1X|8|@]|9|@]|A|$]]|$1|10|3|11|5|6|7|1Y|8|@$F|1Z|G|20|H|I]|$F|21|G|22|H|I]|$F|23|G|24|H|I]|$F|25|G|26|H|I]|$F|27|G|28|H|I]|$F|29|G|2A|H|I]]|9|@]|A|$]]|$1|12|3|-4|5|6|7|2B|8|@]|9|@]|A|$]]]|13|$]]

I think it is possible in the following way:

<h2>1. Using TypeDescriptor</h2>

In your <code>CustomDesignerAttribute</code> overwrite <code>TypeId</code>:

<pre><code>public override object TypeId
{
 get
 {
 return Key.GetHashCode();
 }
 }
</code></pre>

The base implementation of <code>TypeId</code> just uses the attribute type, so no parameters would be involved.

Then u can use 
<code>TypeDescriptor.GetAttributes(typeof(ChildClass)).OfType&lt;CustomDesignerAttribute&gt;()</code>

<code>TypeDescriptor</code> (in contrast to <code>GetType().GetCustomAttributes</code>) returns only one attribute based on the same <code>TypeId</code>. I tested it and it is the most derived attribute matching the <code>TypeId</code> that is returned. 

So if your <code>TypeId</code> represents the key of your attribute then you can overwrite it on derived classes - when using <code>TypeDescriptor</code> to get the attribute! Note that still multiple attributes are possible as long as they differ in their key.

Note: TypeDescriptor also finds dynamically added attributes (added at runtime)

<h2>2. Using Remove Property</h2>

You could add a public <code>bool Remove { get; set; }</code> to your <code>CustomDesignerAttribute</code>. You can set it to <code>true</code> in your derived class while setting the other parameters identical to the base class attribute you want to remove. Then add another attribute with same key but your desired value to your derived class. When getting the attributes you have to evaluate the Remove property in a smart manner. Either using TypeDescriptor as in 1) with <code>TypeId</code> e.g. returning <code>Key.HashCode() + Value.GetHashCode()</code> or using <code>GetType().GetCustomAttributes</code>, in both ways you have to loop through the list of attributes and filter. You have to be aware in what order these lists are, if most derived types first or the other way around.

We have a custom attribute

<pre><code>[AttributeUsage(AttributeTargets.All, AllowMultiple = true)]
public class CustomDesignerAttribute: Attribute
</code></pre>

then we have a base class decorated with this attribute

<pre><code>[CustomDesigner(someKey, someValue)]
public class BaseClass
</code></pre>

then we have a class derived from this one, decorated with same attribute (with same key, different value)

<pre><code>[CustomDesigner(someKey, someOtherValue)]
public class ChildClass : BaseClass
</code></pre>

Is there possibility that ChildClass don't create a duplicate of attribute but overwrite a value for existing key instead (overwrites whole parent attribute)? 
If not, what's the best pattern for getting default value from BaseClass if ChildClass has not defined his own?

Overwrite customattribute on derived class

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我们有一个自定义属性[AttributeUsage(AttributeTargets.All, AllowMultiple = true)]public class CustomDesignerAttribute: Attribute然后我们就有了一个用这个属性修饰的基类[CustomDesigner(someKey,...

问覆盖派生类的自定义属性
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