自定义UIScrollView 滚动条（适合大部分继承自UIScrollView的控件，如UITextView,UITableView等）

转载自：http://blog.csdn.net/liubo0_0/article/details/7067460

滚动条只是显示作用，不能点击拖动。

当然可以根据自定义样式。

想法很简单，就是在UIScrollView里面先增加一个竖条，在增加一个图标。

通过移动UIScrollView里面的坐标，来实现图标移动的效果。

UIScrollView ＊leftScroll = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 40, 200, 630)];

leftScroll.delegate = self;

leftScroll.showsVerticalScrollIndicator = NO;

leftScroll.bounces = NO;

[self.view addSubview:leftScroll];

// 添加 竖条

NSString *pathS = [[NSBundle mainBundle] pathForResource:@"ss" ofType:@"png"];

UIImage *imageS = [[UIImage alloc] initWithContentsOfFile:pathS];

UIImageView *imageSView = [[UIImageView alloc] initWithImage:imageS];

imageSView.frame = CGRectMake(190,0,2,200*[arr count]);
//第一处

[leftScroll addSubview:imageSView];

// 添加 图标

pathS = [[NSBundle mainBundle] pathForResource:@"gg" ofType:@"png"];

imageS = [[UIImage alloc] initWithContentsOfFile:pathS];

imageGView = [[UIImageView alloc] initWithImage:imageS];

imageGView.frame = CGRectMake(186,10,10,27);

[leftScroll addSubview:imageGView];

// 当移动调用此方法

- (void)scrollViewDidScroll:(UIScrollView *)scrollView

{
//第二处

float p = 0;

p = scrollView.contentOffset.y/(scrollView.contentSize.height - scrollView.frame.size.height);

imageGView.frame = CGRectMake(186,p*scrollView.contentSize.height,10, 27);

}

//实际使用中对两处做了修改，因为我是在自定义UITextView时引用的代码

第一处：

float h = (self.label_alert_info.frame.size.height
* self.label_alert_info.frame.size.height)/self.label_alert_info.contentSize.height;

imageGView.frame =
CGRectMake(256,0,5,h);

第二处：

if (([scrollView
isKindOfClass:[UITextView
class]])) {

float h =
0.0;

float p =
0.0;

h = (scrollView.frame.size.height * scrollView.frame.size.height)/scrollView.contentSize.height;

p = (scrollView.contentOffset.y + scrollView.frame.size.height)/scrollView.contentSize.height*scrollView.frame.size.height
- h;

imageGView.frame =
CGRectMake(256,p + scrollView.contentOffset.y,5,h);

}