UIView Touch，觸控事件處理

UIResponser有四個對觸控碰處理的method(interface)介面

UIView與UIViewController 都繼承至UIResponser

因此只要是UIView與UIViewController的子類，實作以下四個method就能對觸控做處理

touchesBegan:withEvent:,
touchesMoved:withEvent:,
touchesEnded:withEvent:,
touchesCancelled:withEvent:

iOS程式初始化流程

1. main()
2. create pool
3. UIApplicationMain(argc,argv,nul,@"delegateClassName");
4. Create UIApplication instance and set the UIApplicationDelegate