Confused about GetCustomAttrib utes from FieldInfo

[CA]

I am learning about attributes and at this point, I am completely
confused.

I have posted some code below. I do not understand the following
points:

1) The TestAttribute does not appear for the StructureChange d field,
i.e. the GetCustomAttrib utes() method does not return any attributes
event though the field has been flagged.

2) If I remove the Bindings.NonPub lic flag, the field StructureChange d
does not appear in the fields array.

I appreciate any help in clarifying my thoughts.

Regards

Chris
--------------------------------------------------
public void TestCode()
{
TesterObjectCla ss toc = new TesterObjectCla ss();
Type t = toc.GetType();
FieldInfo[] fields =
t.GetFields(Bin dingFlags.NonPu blic|BindingFla gs.Public|Bindi ngFlags.Instanc e|BindingFlags. DeclaredOnly);
Type TestAttr = typeof(TestAttr ibute);
foreach (FieldInfo fi in fields)
{
object[] attr = fi.GetCustomAtt ributes(TestAtt r, false);
// StructureChange d : attr.Length = 0; vIsBoolean : attr.Length = 1;
Console.WriteLi ne("Field Name: {0}, Length: {1}", fi.Name,
attr.Length);

}
}

[AttributeUsage( System.Attribut eTargets.All,
AllowMultiple=f alse,
Inherited=false )]
public class TestAttribute : Attribute
{
}

public class TesterObjectCla ss
{

[TestAttribute] public event EventHandler StructureChange d;
[TestAttribute] public bool vIsBoolean;
public double vIsDouble;
}

[Mattias Sjögren]

Chris,

I am learning about attributes and at this point, I am completely
confused.
First you have to understand that the syntax

public event EventHandler StructureChange d;

is sort of a shortcut for the more explicit version

private EventHandler StructureChange d;
public event EventHandler StructureChange d
{
add { ... }
remove { ... }
}

So it compiles down to a private delegate field and add and remove
accessor methods for the event.

1) The TestAttribute does not appear for the StructureChange d field,
i.e. the GetCustomAttrib utes() method does not return any attributes
event though the field has been flagged.
The attribute is associated with the event by default. To put it on
the underlying field, you use

[field: TestAttribute] public event EventHandler StructureChange d;

2) If I remove the Bindings.NonPub lic flag, the field StructureChange d
does not appear in the fields array.

Because the delegate field is private, only the event is public.

Mattias

--
Mattias Sjögren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/
Please reply only to the newsgroup.

[CA]

Mattias,

That was a very elegant explanation. Thank you for clearing up my confusion.

Regards

Chris

Mattias Sjögren <ma************ ********@mvps.o rg> wrote in message news:<ej******* *******@TK2MSFT NGP12.phx.gbl>. ..

Chris,

I am learning about attributes and at this point, I am completely
confused.

First you have to understand that the syntax

public event EventHandler StructureChange d;

is sort of a shortcut for the more explicit version

private EventHandler StructureChange d;
public event EventHandler StructureChange d
{
add { ... }
remove { ... }
}

So it compiles down to a private delegate field and add and remove
accessor methods for the event.

1) The TestAttribute does not appear for the StructureChange d field,
i.e. the GetCustomAttrib utes() method does not return any attributes
event though the field has been flagged.

The attribute is associated with the event by default. To put it on
the underlying field, you use

[field: TestAttribute] public event EventHandler StructureChange d;

2) If I remove the Bindings.NonPub lic flag, the field StructureChange d
does not appear in the fields array.

Because the delegate field is private, only the event is public.

Mattias