C# Attributes and attribute location/targets

attributes, c#

Solution

you have to specify target explicitly in case where the target is not represented in code. I know only three that targets, assembly, module and return:

[return: MyAttribute]
public static int meth(

for class specifying class: is excessive, compiler can understand what do you meant

Problem

I'm reading up about attributes and understand that they can be made to apply to different target entities with you code - (see Attribute Targets). So, looking at the AssemblyInfo.cs file in my project, I can see the following: ``` [assembly: AssemblyTitle("AttributesDemo")] [assembly: AssemblyDescription("")] ``` Which makes sense to me. An attribute whose target is the assembly. In my code I can add an attribute on a class as follows: ``` [MyAttribute] class MySerialzableClass { ``` With `MyAttribute` being: ``` [AttributeUsage (AttributeTargets.All)] public class MyAttribute : System.Attribute { } ``` So, I got to thinking about the `assembly:` statement in the first code block. And tried this, just for experimentation: ``` [class: MyAttribute] class MySerialzableClass { ``` This gives the compiler warning: 'class' is not a recognized attribute location. All attributes in this block will be ignored. So my question is this - Why do have to specify the Attribute Target on some attributes and are not requried, or permitted to for others? Moreover, for which ones must you do this?

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