Dotnet (C #) Learning-How much you learn!

Foreword: Dotnet (C #) frame is huge, the knowledge is numerous, how far have you learned?
Here are the basics that I think must be mastered (no matter what development you use dotnet), have you mastered it?
(Incomplete, updated in succession)

CLR (Common language runtime)
1, the primitive type;
2, value type and reference type;
3, object (common objects operation);

Second, Class design (type)
1, constant and field;
2, method;
3, attributes;
4, the indexer;
5, the incident;
6, access modifiers;

Three, basic class (base type)
1, String (text processing);
2, enum (enum type);
(3) Array (array)/collection (set);
4, Interface (interface);
5, attribute (characteristic);
6, Delegate (commissioned);
Iv. Class Manage (type Management)
1, initialization and cleaning;
2, type inspection and conversion;
3, abnormal;
4, garbage collection;
5, serialization;
6, reflection;
7, application domain;
V. Other
1, multithreading;
2, asynchronous call;
3, resources;
4, safety;