问题描述
考虑一个程序集包含一个或多个类型的情况，该类型具有自定义属性MyAttribute，并且您需要获取这些类型的列表.使用 IsDefined vs. GetCustomAttributes 除了更紧凑的语法?一个人是否暴露/隐藏了另一个人没有的东西?一个比另一个更有效吗?
Consider the case where an assembly contains one or more types attributed with a custom attribute MyAttribute and you need to get a list of these types. Is there any benefit of using IsDefined vs. GetCustomAttributes aside from the more compact syntax? Does one expose/hide something that the other doesn't? Is one more efficient than the other?
以下是演示每种用法的代码示例:
Here is a code sample demonstrating each usage:
Assembly assembly = ...
var typesWithMyAttributeFromIsDefined =
from type in assembly.GetTypes()
where type.IsDefined(typeof(MyAttribute), false)
select type;
var typesWithMyAttributeFromGetCustomAttributes =
from type in assembly.GetTypes()
let attributes = type.GetCustomAttributes(typeof(MyAttribute), false)
where attributes != null && attributes.Length > 0
select type;
推荐答案
快速测试了这两个方法，发现 IsDefined 比 GetCustomAttributes 快很多
Done a quick test with the two methods and it seems IsDefined is a lot faster than GetCustomAttributes
200000 次迭代
IsDefined average Ticks = 54
GetCustomAttributes average Ticks = 114
希望这会有所帮助:)
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