On 29 May 10, at 15:26 , spir ☣ wrote: > I cannot do that. C0 (and all classes) instances need a text method. I also > cannot have 2 methods (one static, one virtual) with different names. It's a > basic feature, always called with the same name. Like getItem for a hierarchy > of collections: every collection must have it, and always under the same > name, so that any client can rely on it.
David is not suggesting you have two methods with different names - his example is demonstrating the different behaviour of static and virtual methods. Calling a static method is determined at compile time - the compiler must use the actual class of your variable (or cast) - so your descendent methods will never be called. This is what is happening to you at the moment - only your base class Text method is called. Calling a virtual method is determined at runtime based upon the actual class held by the variable (cast) - it seems this is exactly what you need. Set your base class Text method as virtual, and each descendent class Text method as override - your code should then function as you require... element := C(list[index]); // casting back text := element.text; if the pointer in list[index] is C1, C1.Text will be called. Regards, Andrew. _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
