internal void CacheDelegateForType(Type anotherDelegateType, DelegateTemplate delegateType)
{
this.cachedDelSamples[anotherDelegateType] = delegateType;
}
public Delegate MakeDelegate(Type targetDelegateType)
{
//check if we already has cache delegate for handle the targetDelegateType
//if not found then create a new one
DelegateTemplate foundTemplate;
if (this._context.GetCacheDelegateForType(targetDelegateType, out foundTemplate))
{
//found sample
//the create new holder from sample template
return(foundTemplate.CreateNewDelegate(targetDelegateType, this));
}
//----------------------------------------------------------------------------------
if (targetDelegateType.BaseType != typeof(MulticastDelegate))
{
throw new ApplicationException("Not a delegate.");
}
MethodInfo invoke = targetDelegateType.GetMethod("Invoke");
if (invoke == null)
{
throw new ApplicationException("Not a delegate.");
}
ParameterInfo[] invokeParams = invoke.GetParameters();
int argCount = invokeParams.Length;
Type returnType = invoke.ReturnType;
bool returnVoid = returnType == typeof(void);
Type[] typelist = null;
if (returnVoid)
{
typelist = new Type[argCount];
for (int i = 0; i < argCount; ++i)
{
typelist[i] = invokeParams[i].ParameterType;
}
}
else
{
typelist = new Type[argCount + 1]; //+1 for return type
for (int i = 0; i < argCount; ++i)
{
typelist[i] = invokeParams[i].ParameterType;
}
typelist[argCount] = returnType;
}
//----------------------------------
//create delegate holder
//you can add more than 1
Type delHolderType = null;
switch (argCount)
{
case 0:
{
//0 input
delHolderType = returnVoid ?
typeof(ActionDelegateHolder) :
typeof(FuncDelegateHolder <>).MakeGenericType(typelist);
} break;
case 1:
{
//1 input
delHolderType = returnVoid ?
typeof(ActionDelegateHolder <>).MakeGenericType(typelist) :
typeof(FuncDelegateHolder <,>).MakeGenericType(typelist);
} break;
case 2:
{
delHolderType = returnVoid ?
typeof(ActionDelegateHolder <,>).MakeGenericType(typelist) :
typeof(FuncDelegateHolder <, ,>).MakeGenericType(typelist);
} break;
case 3:
{
delHolderType = returnVoid ?
typeof(ActionDelegateHolder <, ,>).MakeGenericType(typelist) :
typeof(FuncDelegateHolder <, , ,>).MakeGenericType(typelist);
} break;
case 4:
{
delHolderType = returnVoid ?
typeof(ActionDelegateHolder <, , ,>).MakeGenericType(typelist) :
typeof(FuncDelegateHolder <, , , ,>).MakeGenericType(typelist);
} break;
default:
{
//create more if you want
throw new NotSupportedException();
}
}
//----------------------------------
//create sample
DelegateTemplate newTemplate = new DelegateTemplate(
delHolderType,
Activator.CreateInstance(delHolderType) as DelegateHolder);
//cache
this._context.CacheDelegateForType(targetDelegateType, newTemplate);
//new delegate created from sample
return(newTemplate.CreateNewDelegate(targetDelegateType, this));
}
//----------------------------------------------------------------------------------------
internal bool GetCacheDelegateForType(Type anotherDelegateType, out DelegateTemplate delSample)
{
return(this.cachedDelSamples.TryGetValue(anotherDelegateType, out delSample));
}