创建一个自定义的UIScrollView Scroller

Question

好吧，我已经遍及互联网试图找到答案，我正在尝试创建一个自定义的UIScrollView滚动器。

这里是一个滚轮

http://postimage.org/image/cg2jvde9z/

http://postimage.org/image/ko0mp3kdj/ 的图片的链接（即白盒只是对我来说，测试滚动型）

我已经得到了滚轮的工作，尽管我需要帮助确定滚动视图每次滚动滚动条时应移动多少像素

这里是一些代码

-(IBAction)scroller_bar:(id)sender withEvent:(UIEvent *)event{  
UIButton *button_sent = (UIButton *)sender; 

UITouch *touch = [[event touchesForView:button_sent] anyObject]; 

CGPoint previousLocation = [touch previousLocationInView:button_sent]; 
CGPoint location = [touch locationInView:button_sent]; 
CGFloat delta_x = location.x - previousLocation.x; 
float left_side = button_sent.center.x + delta_x; 
float right_side = button_sent.center.x + delta_x; 
if (right_side > button_sent.center.x) { 
    scroll_right = YES; 
} 
else{ 
    scroll_right = NO; 
} 
if (left_side <= 13 + 50.5 || right_side >= 307 - 50.5) { 

} 
else{ 
    button_sent.center = CGPointMake(button_sent.center.x + delta_x, 
            button_sent.center.y); 

    if (scroll_right) { 

    [selection_scroll setContentOffset:CGPointMake(selection_scroll.contentOffset.x - (Help HERE!), selection_scroll.contentOffset.y) animated:YES]; 
    } 
    else{ 

     [selection_scroll setContentOffset:CGPointMake(selection_scroll.contentOffset.x + (Help HERE!), selection_scroll.contentOffset.y) animated:YES]; 


    } 
} 

}

在上面的代码，你会看到一个“（帮助在这里！）”，

这正是我试图找出有多少像素的，我应该移动滚动视图。这是一个令人困惑的问题，希望你能理解。

谢谢:)

Answer 1

我不知道苹果是否会批准这个或没有，但下面写的代码可以改变scollView的滚动图片

for (UIImageView *img in yourscrollView.subviews) { 
    [img setImage:[UIImage imageNamed:@"your custom scroller image"]]; 
}