I spent part of today scratching my head and dredging up long-forgotten details of the .Net Framework and C# over at BrainBench.com – to my relief, I didn’t disgrace myself: a test score average of 4.25 puts me in good stead for my forthcoming MCP exam later in June.

Some of the tricky areas:

• C# strings live in the intern pool
• Structs vs. Classes – particularly with reference to how Structs get auto-boxed when casting to an interface
• The difference between readonly variables and constants – illustrated by the ilasm generated
• A Remoting refresher – the issue of Remoting and GC is particularly non-obvious
• Some info on valid Type Conversions – crucially, casting anything to a char is invalid, which gets over some naaasty C-style hacks
• Items that can be serialized by XmlSerializer:
  The following items can be serialized using the XmLSerializer class.
  • Public read/write properties and fields of public classes.
  • Classes that implement ICollection or IEnumerable. (Note that only collections are serialized, not public properties.)
  • XmlElement objects.
  • XmlNode objects.
  • DataSet objects.
• Forcing the compiler to check for CLS-compliancy – [CLSCompliant(true)]
• A whole bunch of stuff on Code Access Security – though the basic idea is quite simple: establish security requirements at compile time, and DEMAND that running code has those permissions before allowing execution (as opposed to running as far as possible with the current credentials/rights)
• Dynamic Methods and Assemblies – use types in System.Reflection.Emit
• Some details on XSD.exe: workarounds, and an improved version – I discovered that even then VS2005 version of XSD.exe has some serious bugs, such as eating memory when presented with a multi-table SP-based dataset.
• Finally (as it were) we have Non-deterministic finalization, and destructors/Dispose() – often safely ignored in simpler code, but can lead to Bad Things if abused in enterprise applications