The simple wording of protocol

1 //2 //TouchView.h3 //Lessonuicontrolandsubclass4 5 6 7 #import<UIKit/UIKit.h>8 9 @classTouchView;Ten //1. Develop agreement, agreement name format: class name +delegate One @protocolTouchviewdelegate <NSObject> A  - @optional -- (void) Touchbegan: (TouchView *) TouchView; the- (void) touchmoved: (TouchView *) TouchView; -- (void) touchended: (TouchView *) TouchView; -- (void) touchcancelled: (TouchView *) TouchView; -  + @end -  + @interfaceTouchview:uiview A  at //2. Write attribute, property name delegate, type is ID, and abide by protocol < class name delegate> -@property (Assign, nonatomic)ID<TouchViewDelegate>Delegate; -  - @end

1 //2 //touchview.m3 //Lessonuicontrolandsubclass4 //5 6 #import "TouchView.h"7 8 @implementationTouchView9 Ten //3. Once the agent is found, let the agent do things One- (void) Touchesbegan: (Nsset *) touches withevent: (Uievent *)Event { A     //determine if delegate has implemented a method -     if([_delegate respondstoselector: @selector (Touchbegan:)]) { - [_delegate touchbegan:self]; the     } - } -  -- (void) touchesmoved: (Nsset *) touches withevent: (Uievent *)Event { +     if([_delegate respondstoselector: @selector (touchmoved:)]) { - [_delegate touchmoved:self]; +     } A } at  -- (void) touchesended: (Nsset *) touches withevent: (Uievent *)Event { -     if([_delegate respondstoselector: @selector (touchended:)]) { - [_delegate touchended:self]; -     } - } in  -- (void) touchescancelled: (Nsset *) touches withevent: (Uievent *)Event { to     if([_delegate respondstoselector: @selector (touchcancelled:)]) { + [_delegate touchcancelled:self]; -     } the } *  $ @end

The simple wording of protocol