Casting with a Hashtable

Question

Hi all. I´ve a problem. I´ve a hashTable that contains some objects. This objects aren´t of the same class, have different types. When I get an object: myObject = hashTable ["myKey"]; the type of myObject is "Object". This way I cant invoke myObject´s methods. myObject.sayHello() -> Compile Error! I have to cast myObject to (myClass); myObject = (myClass) hashTable ["myKey"]; but I dont know what is myClass at compiling time. Can I do somethig similar to?: myObject = (myObject.getType()) hashTable ["myKey"]; Sorry, but my english is too poor. And Thanks!!!

spgilmore · Answer

I agree. It is always best to have a collection of all the same types. If you need to work with multiple types I would use a host object containing a collection for each one or find another way to do it.

shimtanny · Answer

Hi You have to distinguish between the possible types. if (myObject is myClass1) { myObject = (myClass1) hashTable[myKey]; } if (myObject is myClass2) { myObject = (myClass2) hashTable[myKey]; } An other approach is to use reflection to determine the members. Then call with reflection the member you wannt. But anyway most of this problems comes from application design. -> Create a base class then use subclassing to specialized classes. Or work with interfaces. -> Or creating a hashTable for each type of object. Simon