Passing any object type to a function

[sameercodes]

Hi there, I have a function

List<BaseEntity> ConvertList(List<BaseEntity> listBaseEntity)
{
//My code
}

Now I am calling the function as follows:

List<ChildEntity> listChild = new List<ChildEntity>();

listChild = ConvertList(listChild);

Here ChildEntity has base class as BaseEntity. On compiling I am getting error as :

Cannot convert type List<ChildEntity> to List<BaseEntity> via a reference conversion, boxing conversion, unboxing conversion, wrapping conversion, or null type conversion

Then I tried defining the function as

List<object> ConvertList(List<object> listObject)
{
//My Code
}

Again I am calling the function as follows:

List<ChildEntity> listChild = new List<ChildEntity>();

listChild = ConvertList(listChild);

Then I got the compile time error as

The best overloaded method match for ConvertList(List<object>)' has some invalid arguments

How do I resolve this issue? The list that I am passing to the ConvertList function could be of any type. Thanks and Regards - Sameer

[KarstenK]

is the object/list type of your function correct? listChild = ConvertList(ref listChild);

Press F1 for help or google it. Greetings from Germany

[sameercodes]

Hi Karsten, I did the exact way as u'd said but got the following error

The best overloaded method match for ConvertList(List<BaseEntity>) has some invalid arguments.

I'll reconstruct the scenario: My function definition is as follows:

List<BaseEntity> ConvertList(List<BaseEntity>)
{
//My code
}

And I am passing a child object which is inherited from base entity:

List<ChildEntity> listChildEntity = new List<ChildEntity>();

listChildEntity = ConvertList(ref listChildEntity);

Thanks - Sameer

[TheDudeJuan]

The parameter in the ConvertList function accepts List but when you call the function you parse a ref of listChildEntity...

Dollartegn 8D

[Estys]

listChild = ConvertList(listChild.ConvertAll(delegate (ChildEntity a) { return a as BaseEntity}))
.ConvertAll(delegate (BaseEntity a) { return a as ChildEntity});

Each item in List<T> must be cast to the appropriate type and back. Do you really need to pass a list? It looks horrible X|

[sameercodes]

Hi Estys, Thanks for the reply. Yeah, I need to pass a list. Can't help it! :sigh: Actually the ChildEntity is just one example. The BaseEntity is a base class for May child entities, say, ChildEntity1, ChildEntity2, ChildEntity3, etc. Thus, the list could be of any of these types and certain convert actions need to be taken on the same. Your solution seems to be great, but aint it a bit complicated. Is there a simpler one? Thanks and Regards - Sameer

[sameercodes]

Hi Estys, Thanks for the reply. Actually the ChildEntity is just one example. The BaseEntity is a base class for many child entities, say ChildEntity1, ChildEntity2, ChildEntity3, etc. Thus, the list could be of any of these types and certain convert actions need to be taken on the same. Your solution seems to be great but if you take a look at the replies before, I have tried this and somehow this dint work. I'll reconstruct the scenario again, in detail. My ConvertList function belongs to a static class, say ListClassStatic Thus I am calling the function as:

listChildList = ListClassStatic.ConvertList(ref listChildList);

Thanks and Regards - Sameer

[Estys]

This works :

static void Conv (BaseEntity baseEntity)
{
baseEntity.id = "b"; //your code here
}

Invoke like this :

listChild.ForEach(Conv);

It doesn't use a list. Your problem with List<T> is that it won't cast to another type.