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Base Types and Interfaces
Type exposes a BaseType property:
Type base1 = typeof (System.String).BaseType;
Type base2 = typeof (System.IO.FileStream).BaseType;
Console.WriteLine (base1.Name); // Object
Console.WriteLine (base2.Name); // Stream
The GetInterfaces method returns the interfaces that a type implements:
foreach (Type iType in typeof (Guid).GetInterfaces())
Console.WriteLine (iType.Name);
IFormattable
IComparable
IComparable'1
IEquatable'1
Reflection provides two dynamic equivalents to C#’s static is operator:
IsInstanceOfType
Accepts a type and instance
IsAssignableFrom
Accepts two types
Here’s an example of the first:
object obj = Guid.NewGuid();
Type target = typeof (IFormattable);
bool isTrue = obj is IFormattable; // Static C# operator
bool alsoTrue = target.IsInstanceOfType (obj); // Dynamic equivalent
IsAssignableFrom is more versatile:
Type target = typeof (IComparable), source = typeof (string);
Console.WriteLine (target.IsAssignableFrom (source)); // True
The IsSubclassOf method works on the same principle as IsAssignableFrom, but
excludes interfaces.
Instantiating Types
There are two ways to dynamically instantiate an object from its type:
• Call the static Activator.CreateInstance method
• Call Invoke on a ConstructorInfo object obtained from calling GetConstructor
on a Type (advanced scenarios)
Activator.CreateInstance accepts a Type and optional arguments that get passed to
the constructor:
Reflecting and Activating Types | 685
Reflection