Category

来源：互联网发布：c语言的平方根编辑：程序博客网时间：2024/05/16 19:26

在上一个工程中，New File,选择Objective-Category,基类型UILabel，名称ClickButton

////  UILabel+ClickButton.h//  ClickButton////  Created by cloud on 13-3-19.//  Copyright (c) 2013年 cloud. All rights reserved.//#import <UIKit/UIKit.h>@interface UILabel (ClickButton)-(void) setShowTitle:(NSString *)text;@end

////  UILabel+ClickButton.m//  ClickButton////  Created by cloud on 13-3-19.//  Copyright (c) 2013年 cloud. All rights reserved.//#import "UILabel+ClickButton.h"@implementation UILabel (ClickButton)-(void) setShowTitle:(NSString *)text{    self.text=[NSString stringWithFormat:@"你按下了%@键",text];}@end

UILabel中就多了一个新的方法：setShowTitle，修改ViewController.m文件。

////  ViewController.m//  ClickButton////  Created by cloud on 13-3-19.//  Copyright (c) 2013年 cloud. All rights reserved.//#import "ViewController.h"#import "UILabel+ClickButton.h"@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad{    [super viewDidLoad];// Do any additional setup after loading the view, typically from a nib.}- (void)didReceiveMemoryWarning{    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}- (IBAction)pressButton:(UIButton*)sender {    //_lblInfo.text=[sender titleForState:UIControlStateNormal];    [_lblInfo setShowTitle:[sender titleForState:UIControlStateNormal]];}- (void)dealloc {    [_lblInfo release];    [super dealloc];}@end

运行结果如下：

说明：category可以为类添加新的方法，但不能添加新的成员变量。

源码地址：点击打开链接