[Mono-dev] Setting Assembly's Attributes / Injecting new attributes

[Jb Evain]

Hey,

Please respond to the mailing list also.

Weston Weems wrote:
> A new CustomAttribute needs a MethodReference, which needs a
> TypeReference. Am I going the wrong route here? I am completely mind
> boggled. Should I create a customattribute like I would in straight
> c#?
> 
> Looks like CustomAttribute in mono namespaces is not the same as
> CustomAttribute in .net framework.

Of course a Mono.Cecil.CustomAttribute is not the same thing as a 
System.Reflection.CustomAttribute.

> I'd like to create a custom attribute thats literally just a string.
> Thats it thats all. I dont get the need for a method ref for a adding
> a string custom attribute to an assembly.

That's not possible. A CustomAttribute have to be of a type, and it have 
to be constructed by a constructor. Obviously you need a method reference.

--
CustomAttribute ca = new CustomAttribute (
	asm.MainModule.Import (
		typeof (AssemblyDescriptionAttribute).GetConstructor (new Type [] 
{typeof (string)})));

ca.ConstructorParameters.Add ("Description");

asm.CustomAttributes.Add (ca);
--

Here is a sample code to create a brand new CustomAttribute of type 
AssemblyDescriptionAttribute. To create the same with C# you would have 
to write:

[AssemblyDescription("Description")]


Of course, it works also with your own attributes.

Jb

> ANyway thanks for any more information
> 
> Wes
> 
> On 2/16/07, Jb Evain <mono at evain.net> wrote:
>> Hi,
>>
>> It's pretty easy to change such a value.
>>
>> foreach (CustomAttribute ca in asm.CustomAttributes) {
>>         if (ca.Constructor.DeclaringType.Name != "AssemblyNameAttribute")
>>                 continue;
>>
>>         ca.ConstructorParameters [0] = "Hello World";
>> }
>>
>> If you want to add a new one, just create a fully constructed
>> CustomAttribute instance to the collection, and save the assembly.
>>
>> Jb
>>
>> Weston Weems wrote:
>> > Today I happened upon Mono.Cecil libraries and I've got to say, quite
>> > mindblowing. I've found something that lookes to be something Cecil
>> > should fairly easily be able to do, however I cant seem to deduce it
>> > from the documentation or lack thereof.
>> >
>> > I've been able to open an assembly with the following
>> >
>> > AssemblyDefinition sourceAssembly =
>> > AssemblyFactory.GetAssembly("MyAssembly.exe");
>> >
>> > Which works and I can loop through the .CustomAttributes etc, but I
>> > cannot seem to figure out on my own how I can overwrite an existing
>> > attribute value, or how to inject a new custom attribute all together.
>> >
>> > I was wondering if somone had a VERY simple example, that perhaps just
>> > changed "AssemblyNameAttribute" to hellow world or something.
>> >
>> > I'd be greatly appreciative as my searching in news groups and such
>> > has kinda come to a dead end.
>> >
>> > Thanks in advance.
>> > Weston
>> > _______________________________________________
>> > Mono-devel-list mailing list
>> > Mono-devel-list at lists.ximian.com
>> > http://lists.ximian.com/mailman/listinfo/mono-devel-list
>>