How to Update a Listbox on Another Form?

Question

Hello. I have a Listbox listBoxA (say) on FormA. Now there are two other Forms FormB and FormC with textboxes textBoxB and textBoxC. The items in listBoxA are added to via textBoxB and textBoxC; either textbox can add an item. Can this be done? How can this be done? Here's what I could come up with: Write item from either textbox to a textfile and read the items from the textfile for the listbox. It works but if FormA (with the listbox) is open I must close it and re-open to see new item(s). Anyone know of a better way especially where I don't have to re-open the Form with the listbox? This is in C#. Thanks!

Anwar Buchoo · Answer

All the pleasure is mine :) Rgds.

AB · Answer

Thanks Anwar for your help!

Anwar Buchoo · Answer

Declare a static variable (FormA SingletonFormA;) of the FormA (within FormA) which is accessible to both FormB && FormC. Create a method e.g. CreateInstance(); within class FormA which has got something like: public static FormA CreateInstance() { if(SingletonFormA == null) // null check { SingletonFormA = new FormA(); // initialise it } return SingletonFormA; } Now create an object of FormA in each of classs FormB && FormC (ObjB ObjC) and make a function call like: // class FormB ObjB = FormA.CreateInstance(); // class FormC ObjC = FormA.CreateInstance(); Then you can call something like: ObjB.ListItem1.Add(testSingletonFromFormB new ListItem()); ObjC.ListItem1.Add(testSingletonFromFormC new ListItem()); The idea here is to use a shared variable amongst your forms.