Delegates And Events

Question

I know what is delegates and events but can't get why i need them.Why i should referece a method with delegates.Can u guyz give me some suggestions and exercises that will help me to get Delegates And Events.

Rajanikant Hawaldar · Accepted Answer

Hi Bidzina Goginashvili,   Let me explain you, one best example to make understand easy is, in car, guage meter is there at dashboard, When it will update?    Only when car moves here moving indicates some action / event is happening / happend. Means we need to invoke event so referenced method will be called only when car moves. here Dashboard is on class1 and CarMove is another class( where delegate and event declaring and invoking event).    Assume in Form1 is car dashboard where gauge control is there Form2 is Where we input accelaration.   The movement input accelarate 100 KM/h at textbox then click on button at forms2  then at form1 Car guage should start displaying accelaration. Try this sample i will assure100% you will understand.     Thanks

Bidzina Goginashvili · Answer

i guessed what is events (and maybe delegates?) only  in your example i have done nothing yet.As i guessed when i input speed on form 2 i want to create event and that click will be mapped on this button and also i would have method which will change dashboard and this method will be mapped to delegate and in Form 1 i would invoke this eventam i correct ?

Mario Scheeren · Answer

Events are the way to inform others (classes / GUI ) that something occurred in your class. Like "Started Process", "Progress", "Finished Process"   Where you need the delegates to describe the Methodhead, like "How to call it".   Another way you need delegates is when it comes to Threads / Tasks when you want your Task to update the GUI you will need to Invoke a Method within the GUI since you cannot call it directly.