UIScrollView的简单使用

由于注释写的比较全面，在这我就把原码拿过来了。

- (void)viewDidLoad

{

    [superviewDidLoad];

    //1.创建scrollview

    UIScrollView *scrollView = [[UIScrollViewalloc]init];

    [self.view addSubview:scrollView];

    //2.创建imageview 将imageview添加到scrollview上进行显示，因为scrollview上不能显示图片

    NSString *imageName = [NSStringstringWithFormat:@"big.jpg"];

    UIImage *image = [UIImage imageNamed:imageName];

    UIImageView *imageview = [[UIImageViewalloc]initWithImage:image];

    //3.将图片的宽高，设置为imageview的宽高

    CGFloat imgW = imageview.image.size.width;

    CGFloat imgH = imageview.image.size.height;

    imageview.frame = CGRectMake(0, 0, imgW, imgH);

    //4.设置scrollview的可视范围

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

    //5.设置scrollview的内容尺寸

    scrollView.contentSize = CGSizeMake(imgW, imgH);

    //6.设置取消滚动条

    scrollView.showsHorizontalScrollIndicator = NO;

    scrollView.showsVerticalScrollIndicator = NO;

    //7.设置scrollview的额外滚动区域

    scrollView.contentInset = UIEdgeInsetsMake(10, 20, 40, 80);

    //8.设置scrollview的当前位置它的x,y值是当前显示的左上角（0，0）

    scrollView.contentOffset = CGPointMake(200, 200);

    //9.设置scrollview的捏合手势实现（缩放），实现需要代理方法，遵循scrollviewdelegate的协议

    scrollView.delegate = self;

    //10.设置缩放的最大，最小比列

    scrollView.minimumZoomScale = 0.2;

    scrollView.maximumZoomScale = 2.0;

    _imageView = imageview;

    [scrollView addSubview:imageview];

}

//scrollview的代理方法，返回将要缩放的view

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

{

    return_imageView;

}