private DelegateMap(Type delegateType, Type thisParameter, SimpleParameterInfo[] methodParameters, Type methodReturn)
{
if (delegateType == null)
{
throw new ArgumentNullException(nameof(delegateType));
}
DelegateType = delegateType;
// delegate info
var invokeMethod = GetDelegateInvokeMethod();
var delegateParams = SimpleParameterInfo.FromParameters(invokeMethod.GetParameters());
var delegateReturn = invokeMethod.ReturnType;
// map
try
{
var hasThis = thisParameter != null;
// Check param count
if (delegateParams.Length != methodParameters.Length + (hasThis ? 1 : 0))
{
throw new Exception("Invalid parameters count.");
}
ParametersMap = new ArgMap[delegateParams.Length];
for (var i = 0; i < ParametersMap.Length; i++)
{
var methodParam = hasThis
? i == 0
? new SimpleParameterInfo(thisParameter)
: methodParameters[i - 1]
: methodParameters[i];
ParametersMap[i] = new ArgMap(i, delegateParams[i], methodParam);
}
RetValMap = new RetValMap(delegateReturn, methodReturn);
}
catch (Exception ex)
{
throw InvalidSignatureException(ex);
}
}
// Method | Delegate
// =======================
// Normal | Normal,Ref
// Ref | Normal,Ref,Out
// Out | Ref, Out
public ArgMap(int index, SimpleParameterInfo @delegate, SimpleParameterInfo method)
{
Delegate = @delegate;
Method = method;
var methodType = method.Type.RemoveByRef();
var delegateType = @delegate.Type.RemoveByRef();
if (method.IsOut || method.IsByRef)
{
// check underlying types are assignable
if (!delegateType.IsAssignableFrom(methodType))
{
throw new ArgumentException("Invalid type for parameter " + index);
}
if (method.IsOut)
{
// check that delegate can accept method's out
if (!(@delegate.IsOut || @delegate.IsByRef))
{
throw new ArgumentException(
$"Invalid modifier for parameter {index}. Should be Out or Ref.");
}
}
}
else
{
if (@delegate.IsOut)
{
throw new ArgumentException($"Invalid modifier for parameter {index}. Should be None or Ref.");
}
// cast up or down should work
if (!delegateType.IsAssignableFrom(methodType) && !methodType.IsAssignableFrom(delegateType))
{
throw new ArgumentException("Invalid type for parameter " + index);
}
}
}
public static DelegateMap Constructor(Type delegateType, ConstructorInfo constructor) =>
new DelegateMap(delegateType, null, SimpleParameterInfo.FromParameters(constructor.GetParameters()),
constructor.DeclaringType);
public static DelegateMap Method(Type delegateType, MethodInfo methodInfo) => new DelegateMap(delegateType, GetThisParameter(methodInfo), SimpleParameterInfo.FromParameters(methodInfo.GetParameters()), methodInfo.ReturnType);