重写UIPageControl实现自定义按钮

重写UIPageControl实现自定义按钮  

我们可以通过继承该类重写函数来更换点按钮的图片现实.

实现思路如下.


新建类继承UIPageControl :

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1. @interface MyPageControl : UIPageControl
2. {
3.     UIImage*imagePageStateNormal;
4.     UIImage*imagePageStateHighlighted;
5. }
6. - (id)initWithFrame:(CGRect)frame;
7. @property (nonatomic, retain) UIImage*imagePageStateNormal;
8. @property (nonatomic, retain) UIImage*imagePageStateHighlighted;
9. @end

声明了初始化该类的函数

用了两个UIImage保存两张图片, 大家知道的, UIPageCotrol的按钮分为两态, 一个是正常,一个是高亮

接下来实现该类以及重写父类方法:


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1. @interfaceMyPageControl(private)  //声明一个私有方法, 该方法不允许对象直接使用
2. - (void)updateDots;
3. @end
4. 
   
5. @implementationMyPageControl  //实现部分
6. 
   
7. @synthesize imagePageStateNormal;
8. @synthesize imagePageStateHighlighted;
9. 
   
10. - (id)initWithFrame:(CGRect)frame { // 初始化
11.     self= [super initWithFrame:frame];
12.     returnself;
13. }
14. 
    
15. - (void)setImagePageStateNormal:(UIImage *)image{  //设置正常状态点按钮的图片
16.     [imagePageStateHighlightedrelease];
17.     imagePageStateHighlighted= [image retain];
18.     [selfupdateDots];
19. }
20. 
    
21. - (void)setImagePageStateHighlighted:(UIImage *)image {// 设置高亮状态点按钮图片
22.     [imagePageStateNormalrelease];
23.     imagePageStateNormal= [image retain];
24.     [selfupdateDots];
25. }
26. 
    
27. - (void)endTrackingWithTouch:(UITouch *)touchwithEvent:(UIEvent *)event { // 点击事件
28.     [superendTrackingWithTouch:touch withEvent:event];
29.     [selfupdateDots];
30. }
31. 
    
32. - (void)updateDots { // 更新显示所有的点按钮
33. 
    
34.     if(imagePageStateNormal || imagePageStateHighlighted)
35.     {
36.         NSArray*subview =self.subviews;  //获取所有子视图
37.         for(NSInteger i = 0; i < [subview count]; i++)
38.         {
39.             UIImageView*dot = [subviewobjectAtIndex:i];  //以下不解释, 看了基本明白
40.             dot.image= self.currentPage == i ? imagePageStateNormal :imagePageStateHighlighted;
41.         }
42.     }
43. }
44. 
    
45. - (void)dealloc { // 释放内存
46.     [imagePageStateNormalrelease], imagePageStateNormal = nil;
47.     [imagePageStateHighlightedrelease], imagePageStateHighlighted = nil;
48.     [superdealloc];
49. }
50. 
    
51. @end

OK, 在添加处加入以下来实例化该对象代码:

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1. MyPageControl *pageControl = [[MyPageControl alloc]initWithFrame:CGRectMake(0,0, 200, 30)];
2. pageControl.backgroundColor = [UIColor clearColor];
3. pageControl.numberOfPages = 5;
4. pageControl.currentPage = 0;
5. [pageControl setImagePageStateNormal:[UIImageimageNamed:@"pageControlStateNormal.png"]];
6. [pageControl setImagePageStateHighlighted:[UIImageimageNamed:@"pageControlStateHighlighted.png"]];
7. [self.view addSubview:pageControl];
8. [pageControl release];