KVC&&KVO初見

2019-11-14 19:49:48

字體：大中小

來源：轉載

供稿：網友

Look，這是一個很簡單的要求，點擊Add me，age +1.

想一想的話很簡單的，設置一個屬性Nsinteger age，點擊button add me，直接加1在重新顯示Lable就好啦，不過，我們今天是來練習KVC和KVO的，蘋果的鍵值編程哈哈

首先我們定義一個Human的類，并且完成了它的初始化方法

#import <Foundation/Foundation.h>@interface human : NSObject@PRoperty (nonatomic,assign) NSString *name;@property (nonatomic,assign) NSInteger age;-(id)initHuman:(NSString *)Initname hisage:(NSInteger) Initage;@end

#import "human.h"@implementation human-(id)initHuman:(NSString *)Initname hisage:(NSInteger)Initage{    if(self=[super init]){        _name=Initname;        _age=Initage;           }    return self;}@end

很普通很簡單。。。

下面在ViewControler中調用該類，完成對這個人的年齡的增加

#import <UIKit/UIKit.h>#import "human.h"@interface ViewController : UIViewController<UIWebViewDelegate>{    human *keith;}@property (weak, nonatomic) IBOutlet UILabel *Infoshow;- (IBAction)Addme:(id)sender;@end

#import "ViewController.h"@interface ViewController ()@end@implementation ViewController-(void)viewWillAppear:(BOOL)animated{    [super viewWillAppear:animated];       keith=[[human alloc]initHuman:@"keith" hisage:26];    self.Infoshow.text=[NSString stringWithFormat:@"name is %@,age is %ld",keith.name,keith.age];    [keith addObserver:self forKeyPath:@"age" options:NSKeyValueObservingOptionOld|NSKeyValueObservingOptionNew context:nil];//}- (IBAction)Addme:(id)sender {    keith.age+=1;      }-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context{    if ([keyPath isEqualToString:@"age"] && object==keith) {          self.Infoshow.text=[NSString stringWithFormat:@"name is %@,age is %ld",keith.name,keith.age];//添加對keith keyPath的監視    }}-(void)dealloc{    [keith removeObserver:self forKeyPath:@"age"];//不用的時候移除注冊}@end