Dynamic Types in Generics?
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Hello people, Is it posible to declare the type of a generic at runtime? I mean, you normaly would have to do something like this: GenericMethod<Type>(); And I want to do something like this: GenericMethod<(expression that evaluates to a type)>(); I have tried a few things but nothing seems to work. MSDN's C# Programming Guide states that: "client code must declare and instantiate a constructed type by specifying a type argument inside the angle brackets. The type argument for this particular class can be any type recognized by the compiler." Thanks!
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Hello people, Is it posible to declare the type of a generic at runtime? I mean, you normaly would have to do something like this: GenericMethod<Type>(); And I want to do something like this: GenericMethod<(expression that evaluates to a type)>(); I have tried a few things but nothing seems to work. MSDN's C# Programming Guide states that: "client code must declare and instantiate a constructed type by specifying a type argument inside the angle brackets. The type argument for this particular class can be any type recognized by the compiler." Thanks!
You could always use a Func here. For instance:
GenericMethod<Func<T, TResult>>();
"WPF has many lovers. It's a veritable porn star!" - Josh Smith
As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.
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You could always use a Func here. For instance:
GenericMethod<Func<T, TResult>>();
"WPF has many lovers. It's a veritable porn star!" - Josh Smith
As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.
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Good link Pete, very concise. :-D
Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)
Why are you using VB6? Do you hate yourself? (Christian Graus) -
Hello people, Is it posible to declare the type of a generic at runtime? I mean, you normaly would have to do something like this: GenericMethod<Type>(); And I want to do something like this: GenericMethod<(expression that evaluates to a type)>(); I have tried a few things but nothing seems to work. MSDN's C# Programming Guide states that: "client code must declare and instantiate a constructed type by specifying a type argument inside the angle brackets. The type argument for this particular class can be any type recognized by the compiler." Thanks!
What kind of expression that evaluates to a type would you have there? Something with reflection? You could probably use reflection to invoke the method with an expression of the type
Type, but I'm not actually sure. Reflection can do a lot though, so why not.. edit: If all else fails, there is still the possibility to compile and run a piece of code that has been generated at runtime. But I wouldn't use that except in emergencies. It's not exactly fast, or a clean design. -
What kind of expression that evaluates to a type would you have there? Something with reflection? You could probably use reflection to invoke the method with an expression of the type
Type, but I'm not actually sure. Reflection can do a lot though, so why not.. edit: If all else fails, there is still the possibility to compile and run a piece of code that has been generated at runtime. But I wouldn't use that except in emergencies. It's not exactly fast, or a clean design.A method which may prove useful is Type.MakeGenericType[^]. I don't fully understand it, but it seems to be a step in the right direction - getting the type of a generic type (without the type specifiers), then calling MakeGenericType on the result to get a dynamically set Type
Between the idea And the reality Between the motion And the act Falls the Shadow
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Hello people, Is it posible to declare the type of a generic at runtime? I mean, you normaly would have to do something like this: GenericMethod<Type>(); And I want to do something like this: GenericMethod<(expression that evaluates to a type)>(); I have tried a few things but nothing seems to work. MSDN's C# Programming Guide states that: "client code must declare and instantiate a constructed type by specifying a type argument inside the angle brackets. The type argument for this particular class can be any type recognized by the compiler." Thanks!
This code creates a generic type and instatiate an object of that type in runtime using MakeGenericType as Computafreak mentioned. I was going to post it last night but I forgot and fell asleep. But now I know you want it in .net 2.0 I have to remove
varandnew[]static void Main(string[] args)
{
Type t = typeof(List<> );
Type gt = t.MakeGenericType(GetTypes());
object gtObj = Activator.CreateInstance(gt);
}private static Type[] GetTypes()
{
return new Type[] { typeof(int) };
}But gtObj is returned as an object (but it is a List). The problem is that you will probably have to use reflection.
Eslam Afifi
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This code creates a generic type and instatiate an object of that type in runtime using MakeGenericType as Computafreak mentioned. I was going to post it last night but I forgot and fell asleep. But now I know you want it in .net 2.0 I have to remove
varandnew[]static void Main(string[] args)
{
Type t = typeof(List<> );
Type gt = t.MakeGenericType(GetTypes());
object gtObj = Activator.CreateInstance(gt);
}private static Type[] GetTypes()
{
return new Type[] { typeof(int) };
}But gtObj is returned as an object (but it is a List). The problem is that you will probably have to use reflection.
Eslam Afifi
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A method which may prove useful is Type.MakeGenericType[^]. I don't fully understand it, but it seems to be a step in the right direction - getting the type of a generic type (without the type specifiers), then calling MakeGenericType on the result to get a dynamically set Type
Between the idea And the reality Between the motion And the act Falls the Shadow
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You're welcome. I read your other post[^] and you don't have to use the FullName of the Type, you can just pass the Type directly which is faster IMHO.
Eslam Afifi
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You're welcome. I read your other post[^] and you don't have to use the FullName of the Type, you can just pass the Type directly which is faster IMHO.
Eslam Afifi