Dynamic keyword does not work with IoC but classic reflection does

Question

I have made a little CQRS API for our system I tried to replace some reflection code by using the dynamic keyword but it does not work Each command handler is Generic `CommandHandler` with a Method `void Execute(TCommand Command)` With reflection it works ``` public void Invoke(Contracts.Commands.Command command) { var handlerType = types[command.GetType()]; var handler = kernel.Get(handlerType); var method = handlerType.GetMethod("Execute"); method.Invoke(handler, new object[] { command }); } ``` `Kernel.Get` is the untyped version of `kernel.Get` in our IoC (Ninject). This works and the generic method Execute of T fires This code fails with a argument mismatch exception ``` public void Invoke(Contracts.Commands.Command command) { var handlerType = types[command.GetType()]; dynamic handler = kernel.Get(handlerType); handler.Execute(command); } ``` If i statically declare the type it works with dynamic ``` dynamic handler = new TestCommandHandler(); handler.Execute(new Te…

Accepted Answer

You need to change your code to look like this:

```
public void Invoke(Contracts.Commands.Command command)
{
    var handlerType = types[command.GetType()];

dynamic handler = kernel.Get(handlerType);
    dynamic cmd = command;
    handler.Execute(cmd);
}
```

Notice that the `command` parameter is first assigned to a dynamic local variable (`cmd`). This allows the type of `cmd` to be evaluated at runtime and keeps the call to `Execute` truly dynamic; where as NOT doing it this way, the `Execute` method is assumed to have a fixed signature of `Execute(Contracts.Commands.Command command)`

Dynamic keyword does not work with IoC but classic reflection does

Solution

Problem