1.初始化

UIScrollView *scrollView = [[UIScrollViewalloc]init];

2.设置尺寸

（1）按照屏幕尺寸

scrollView.frame =self.view.bounds;

（2）自定义尺寸

scrollView.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);

3.设置背景色

scrollView.backgroundColor = [UIColorredColor];

4.添加到View上

[self.viewaddSubview:scrollView];

5.在UIScrollView上添加image

//1.先初始化，再设置图片和尺寸

      UIImageView *imageView = [[UIImageView alloc] init];

      UIImage *image = [UIImage imageNamed:@"a11.jpg"];

      imageView.image = image;

      imageView.frame = CGRectMake(0, 0, image.size.width, image.size.height);

      [scrollView addSubview:imageView];

//2.先得到图片，通过图片去创建UIImageView

   UIImage *image = [UIImageimageNamed:@"a9.jpg"];

   _imageView = [[UIImageViewalloc]initWithImage:image];

    [scrollViewaddSubview:_imageView];

其他属性设置：

//设置滚动区域  如果宽设为0 ，就不能水平滚动

    scrollView.contentSize =CGSizeMake(image.size.width, image.size.height);

    //设置当前滚动的位置（左上角的坐标）

    scrollView.contentOffset =CGPointMake(500,500);

    //在四周添加滚动范围

    scrollView.contentInset =UIEdgeInsetsMake(0,0,0, 0);

    //设置是否显示显示滚动条(水平，垂直)

//    scrollView.showsHorizontalScrollIndicator = NO;

    scrollView.showsVerticalScrollIndicator =NO;

    //设置滚动条样式(三种)

    scrollView.indicatorStyle =UIScrollViewIndicatorStyleBlack;

//    scrollView.indicatorStyle = UIScrollViewIndicatorStyleDefault;

//    scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite;

    //设置是否可以滚动

    scrollView.scrollEnabled =YES;

    //设置弹性效果

//    scrollView.bounces = NO;

    //即使图片小于滚动范围，也可以用弹性效果

    scrollView.alwaysBounceVertical =YES;

    scrollView.alwaysBounceHorizontal =YES;

@interface ViewController ()  <UIScrollViewDelegate>

{

   UIImageView *_imageView;

}

@end

//设置代理为self

    scrollView.delegate =self;

    scrollView.maximumZoomScale =2;

#pragma mark 先确定要缩放的控件是谁

-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{

    return_imageView;

}

    scrollView.minimumZoomScale =0.5;

UI：UIScrollView滚动视图