The default member can be found by getting the ParameterInfo for the parameter. This property will return the default value and type:
public Object DefaultValue {get;}
If there is no default value, this property will return Value.DBNull. For example,
MethodInfo m = t.GetMethod (“foo”); ParameterInfo [] ps = m.GetParameters(); for (int i = 0; i < ps; I++) { if (ps[i].DefaultValue != Value.DBNull) { Console.WriteLine (“Default Value == {0}[{1}]”, ps[i].DefualtValue, ps[i].DefualtValue.VariantType); } }