This is a super old question, but since it has not been answered and I just stumbled upon this problem, here are some possible solutions:
Make sure that the access modifier of the resx is set to public!
Link to the resx file
See here
Then you either acces the string directly with
var translatedString = Resources.NAME_OF_THE_STRING_IN_RESX_FILE;
or via ResourceManager
var resourceManager = new ResourceManager("FULLY.QUALIFIED.NAMESPACE.NO.EXTENSION", Assembly.GetExecutingAssembly());
var translatedString = resourceManager.GetString("NAME_OF_THE_STRING_IN_RESX_FILE");
Direct access when you have a reference to the project
var translatedString = [FULLY.QUALIFIED.NAMESPACE.NO.EXTENSION].NAME_OF_THE_STRING_IN_RESX_FILE;
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…