c# - MEF not importing methods that has attribute which allows multiple -

created metadataattribute allows using multiple.

[metadataattribute] [attributeusage(attributetargets.method, allowmultiple = true)] public class businesslogicmetadataattribute : exportattribute, ibusinesslogicmetadata {      //...... } 

then using getexports<t>() import methods.

//..... var imported = _container.getexports<action<object, evantargs>, ibusinesslogicmetadata>("myplugin"); //..... 

here plugin method:

[businesslogicmetadata("myplugin")] [businesslogicmetadata("myplugin1")] public void test(object sender, eventargs e) {     //.... } 

get exports not returning plugin method because of alowmultiple=true in metadataattribute. works fine if set metadataattribute allowmultiple = false , remove second attribute of plugin method.

why can't have 2 attributes on plugin method?

thanks help!

not sure if work particular case since don't know entire design , ultimate goal, since you're creating meta attrib , on, wrap flag enum (see enumeration types bit flags) in businesslogicmetadataattribute, is, instead of using strings, use flags enum, below

[businesslogicmetadata(myflagenum.myplugin | myflagenum.myplugin1)] public void test(object sender, eventargs e) {     //.... } 

update: multiple exports without using flag enums, inherit attribute instead of exportattribute, there few discussions problem around web

[metadataattribute] [attributeusage(attributetargets.method, allowmultiple = true)] public class businesslogicmetadataattribute : attribute, ibusinesslogicmetadata {      //...... }