UIScrollView代理方法的实现

 

- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView

 

{

 

    NSLog(@"scrollViewWillBeginDragging");

 

}

 

2.将要结束滑动

 

- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inoutCGPoint *)targetContentOffset NS_AVAILABLE_IOS(5_0)

 

{

 

    NSLog(@"scrollViewWillEndDragging");

 

}

 

注意该方法常用在当用户滚动完屏幕时加载图片，HTTP请求加载，这样会提高效率

 

3.已经结束滑动

 

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate

 

{

 

    NSLog(@"scrollViewDidEndDragging");

 

}

 

4.将要减速

 

- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView

 

{

 

    NSLog(@"scrollViewWillBeginDecelerating");

 

}

 

5.已经减速

 

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView   // called when scroll view grinds to a halt

 

{

 

    NSLog(@"scrollViewDidEndDecelerating");

 

}

 

6.已经停止滚动

 

- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView

 

{

 

    NSLog(@"scrollViewDidEndScrollingAnimation");

 

}

 

isMemberOfClass和isKindOfClass的异同

 

两者都能检测出一个对象是否是某个类的成员，区别是：

 

isKindOfClass不但可以检测出一个对象是否是某一类的成员，也可以确定一个对象是否是派生自该类的成员，而isMemberOfClass不行

 

7.用代理方法实现图片的放大缩小

 

 

 

-(void)viewDidLoad  
{  
    ScrollView=[[[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 320, 460)] autorelease];  
    ScrollView.delegate=self;  
    ScrollView.backgroundColor=[UIColor redColor];  
    ScrollView.scrollsToTop=YES;  
    ScrollView.contentSize=CGSizeMake(320, 460);  
    ScrollView.maximumZoomScale=2;  
    ScrollView.minimumZoomScale=0.5;  
    ScrollView.backgroundColor=[UIColor yellowColor];  
    [self.view addSubview:ScrollView];  
      
  imageView=[[[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320, 460)] autorelease];  
    imageView.image=[UIImage imageNamed:@"image1.jpg"];  
    [ScrollView addSubview:imageView];  
   
}  
  
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView  
{  
    return imageView;  
}  
- (void)scrollViewWillBeginZooming:(UIScrollView *)scrollView withView:(UIView *)view NS_AVAILABLE_IOS(3_2)  
{  
    NSLog(@"begin scrollview");  
}  
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale  
{  
NSLog(@"did  end  finih");  
}  

 

 

补充：综合编程 , 其他综合 ,