简单的使用滚动视图的setContentOffSet和setContentSize以及几种简单的动画使用

#import "ViewController.h"

@interface ViewController ()

/** 一个scrollView 控件 */

@property (weak, nonatomic) IBOutlet UIScrollView *scrollView;

@end

@implementation ViewController

/** 点击最上面按钮回到最上面*/

/**

 contentOffset: 设置偏移量 

 根据自己要求设置偏移量.

 */

- (IBAction)top:(id)sender {

        CGPoint offset = CGPointMake(self.scrollView.contentOffset.x, 0);

    [self.scrollView setContentOffset:offset animated:YES];

}

- (IBAction)left:(id)sender {

    // 动画用法1

    [UIView animateWithDuration:2.0 animations:^{

        self.scrollView.contentOffset = CGPointMake(0, self.scrollView.contentOffset.y);

        

    }];

}

- (IBAction)right:(id)sender {

    // 动画用法2 麻烦,不建议用

    [UIView beginAnimations:nil context:nil];

    [UIView setAnimationDelay:2.0];

    [UIView setAnimationDelegate:self]; // 可设置代理

    [UIView setAnimationDidStopSelector:@selector(stop)];

    [UIView setAnimationWillStartSelector:@selector(start)];

    

    CGFloat offsetX = self.scrollView.contentSize.width - self.scrollView.frame.size.width;

    self.scrollView.contentOffset = CGPointMake(offsetX, self.scrollView.contentOffset.y);

    

    [UIView commitAnimations]; // 结束动画

}

- (IBAction)bottom:(id)sender {

//    CGFloat offsetY = self.scrollView.contentSize.height - self.scrollView.frame.size.height;

//    CGPoint offset = self.scrollView.contentOffset;

//    offset.y = offsetY;

//    self.scrollView.contentOffset = offset;

    

    // 动画用法3

    [UIView animateWithDuration:2.0 animations:^{

        

        CGFloat offsetY = self.scrollView.contentSize.height - self.scrollView.frame.size.height;

        self.scrollView.contentOffset = CGPointMake(0, offsetY);

    } completion:^(BOOL finished) {

        NSLog(@"完成");

    }];

        //    self.scrollView.contentOffset.y = offsetY;

    // OC语法细节：不允许直接修改OC对象的结构体属性的成员

    

}