Dynamic – key word, specialized form of object.
limitations – doesn’t work to lambda, doesn’t work to extension methods
when to use?
- reflection late binding methods
- COM
code examples
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using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace dynamic { class Program { static void Main(string[] args) { ChangeDynamicDataType(); Console.ReadLine(); } static void ChangeDynamicDataType() { dynamic t = "Hello"; Console.WriteLine("t is type of {0}", t.GetType()); t = false; Console.WriteLine("t is type of {0}", t.GetType()); t = 123; Console.WriteLine("t is type of {0}", t.GetType()); t = new List<int>(); Console.WriteLine("t is type of {0}", t.GetType()); t.AnyBullShitHereWillBeCompiled(); // no checks of compilator // so use try catch !!! try { t.AnyBullShitHereWillBeCompiled(); // <<< } catch (Microsoft.CSharp.RuntimeBinder.RuntimeBinderException ex) { Console.WriteLine(ex.Message); } } } // where can we use dynamic ? class SomeDynamicClass { // field private static dynamic myDynamicField; //property public dynamic DynamicProperty { get; set; } // return value public dynamic DynamicMethod(dynamic SomeDynamicParam) { dynamic dynamicLocalVar = "local var"; int myInt = 10; if (SomeDynamicParam is int) { return dynamicLocalVar; } else { return myInt; } } } } |
Late binding example – 2 examples – with dynamic key word and without
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static void CreateUsingLateBinding(Assembly asm) { Type TSportsCar = asm.GetType("CarLibrary.MiniVan"); object obj = Activator.CreateInstance(TSportsCar); MethodInfo mi = TSportsCar.GetMethod("TurboBoost"); MethodInfo mi2 = TSportsCar.GetMethod("MethodWithArgs"); object[] args = {10,70} mi.Invoke(obj, null); mi2.Invloke(obj,args); } static void CreateUsingLateBindingWithDynamicKeyWord(Assembly asm) { try { Type TSportsCar = asm.GetType("CarLibrary.MiniVan"); dynamic obj = Activator.CreateInstance(TSportsCar); obj.TurboBoost(); obj.MethodWithArgs(10,70); } catch (Exception ex) { Console.WriteLine(ex.Message); } } |