Reflection provides objects (of type Type) that describe assemblies, modules and types. You can use reflection to dynamically create an instance of a type, bind the type to an existing object, or get the type from an existing object and invoke its methods or access its fields and properties. If you are using attributes in your code, reflection enables you to access them. For more information, see Attributes.
Here’s a simple example of reflection using the static method GetType
– inherited by all types from the Object
base class – to obtain the type of a variable:
// Using GetType to obtain type information:
int i = 42;
System.Type type = i.GetType();
System.Console.WriteLine(type);
Result:
System.Int32
The following example uses reflection to obtain the full name of the loaded assembly.
// Using Reflection to get information from an Assembly:
System.Reflection.Assembly info = typeof(System.Int32).Assembly;
System.Console.WriteLine(info);
Result:
mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
Reflection is useful in the following situations:
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When you have to access attributes in your program’s metadata. For more information, see Retrieving Information Stored in Attributes.
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For examining and instantiating types in an assembly.
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For building new types at runtime. Use classes in System.Reflection.Emit.
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For performing late binding, accessing methods on types created at run time. See the topic Dynamically Loading and Using Types.