理解UIScrollView时可以假设这样的一个场景:在一个漆黑的屋子里的墙上有一副大的画，墙是可以上下左右滚动，一个矩形的手电筒固定着，开始时画的左上角坐标与矩形光的左上角坐标对应。人可以用手电筒的光来看这幅画。

//
//  ViewController.m
//  UIScrollView
//
//  Created by City--Online on 15/5/20.
//  Copyright (c) 2015年 XQB. All rights reserved.
//#import "ViewController.h"@interface ViewController ()<UIScrollViewDelegate>
@property(nonatomic,strong) UIScrollView *scrollView;
@end@implementation ViewController- (void)viewDidLoad {[super viewDidLoad];//Frame类似矩形手电筒发出的光 眼睛每次只能看到矩形大小的东西_scrollView=[[UIScrollView alloc]initWithFrame:CGRectMake(10, 100, self.view.bounds.size.width, 100)];//画布_scrollView.contentSize=CGSizeMake(self.view.bounds.size.width*3, self.view.bounds.size.height);//画布里墙角的距离 类似CSS的盒子模型  contentSize、contentInset共同组成整块墙_scrollView.contentInset=UIEdgeInsetsMake(10, 10, 10, 10);//设置代理_scrollView.delegate=self;//指定控件是否只能在一个方向上滚动_scrollView.directionalLockEnabled=YES;//控制控件遇到边框是否反弹_scrollView.bounces=YES;//控制垂直方向遇到边框是否反弹_scrollView.alwaysBounceVertical=NO;//控制水平方向遇到边框是否反弹_scrollView.alwaysBounceHorizontal=NO;//控制控件是否整页翻动_scrollView.pagingEnabled=YES;//控制控件是否能滚动_scrollView.scrollEnabled=YES;//控制是否显示水平方向的滚动条_scrollView.showsHorizontalScrollIndicator=YES;//控制是否显示垂直方向的滚动条_scrollView.showsVerticalScrollIndicator=YES;//指定滚动条在scrollerView中的位置_scrollView.scrollIndicatorInsets=UIEdgeInsetsMake(0, 50, 0, 0);//设定滚动条的样式_scrollView.indicatorStyle=UIScrollViewIndicatorStyleBlack;//减速速率_scrollView.decelerationRate=3.0;//    //设置墙左上角坐标移动到指定的Point//    [_scrollView setContentOffset:CGPointMake(self.view.bounds.size.width, 0) animated:YES];//    //滚动到指定矩形的边缘 使得该矩形可见//    [_scrollView scrollRectToVisible:CGRectMake(self.view.bounds.size.width, 0, self.view.bounds.size.width, self.view.bounds.size.height) animated:YES];//显示滚动条,但是滚动条(ScrollBar Indicators) 只会显示大概1.5秒左右的时间，就会自动隐藏//    [_scrollView flashScrollIndicators];//如果用户已经触及的内容视图但可能还没有开始拖动它。这个属性的值便是YESBOOL IsTracking =_scrollView.tracking;NSLog(@"tracking=%d",IsTracking);//是否在被拖拽BOOL IsDragging=_scrollView.dragging;NSLog(@"dragging=%d",IsDragging);//是否在减速BOOL  IsDecelerating=_scrollView.decelerating;NSLog(@"decelerating=%d",IsDecelerating);//是否延时调用开始滚动的方法 if NO, we immediately call -touchesShouldBegin:withEvent:inContentView:_scrollView.delaysContentTouches=YES;//是否接触取消touch的事件_scrollView.canCancelContentTouches=YES;//缩小的最小值_scrollView.minimumZoomScale=0.5;//放大的最大值_scrollView.maximumZoomScale=2;//当前缩放值_scrollView.zoomScale=1;//缩放到指定的大小//    - (void)setZoomScale:(CGFloat)scale animated:(BOOL)animated//缩放到指定的Rect//    - (void)zoomToRect:(CGRect)rect animated:(BOOL)animated//控件的大小是否正在改变BOOL IsZooming= _scrollView.zooming;NSLog(@"zooming=%d",IsZooming);//设置缩放到边界时是否反弹_scrollView.bouncesZoom=YES;//是否进行缩放反弹BOOL IsZoomBouncing= _scrollView.zoomBouncing;NSLog(@"zoomBouncing=%d",IsZoomBouncing);//滚动到顶部BOOL IsScrollsTop= _scrollView.scrollsToTop;NSLog(@"scrollsToTop=%d",IsScrollsTop);//开始拖到时隐藏键盘_scrollView.keyboardDismissMode=UIScrollViewKeyboardDismissModeOnDrag;//获取拖动手势UIGestureRecognizer *panGestureRecognizer=_scrollView.panGestureRecognizer;//获取撮合手势UIGestureRecognizer *pinchGestureRecognizer=_scrollView.pinchGestureRecognizer;for (int i=0; i<3; i++) {UIImageView *imgView=[[UIImageView alloc]initWithImage:[UIImage imageNamed:[NSString stringWithFormat:@"%d.png",i]]];imgView.frame=CGRectMake(self.view.bounds.size.width*i, 0, self.view.bounds.size.width, self.view.bounds.size.height) ;[_scrollView addSubview:imgView];}_scrollView.userInteractionEnabled=YES;_scrollView.scrollEnabled=YES;[self.view addSubview:_scrollView];
//    self.view.backgroundColor=[UIColor yellowColor];}//UIScrollViewDelegate
//视图滚动时触发
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{NSLog(@"scrollViewDidScroll");
}
//视图缩放时触发
- (void)scrollViewDidZoom:(UIScrollView *)scrollView
{NSLog(@"scrollViewDidZoom");
}
//开始拖动时触发
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{NSLog(@"scrollViewWillBeginDragging");
}- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset
{NSLog(@"scrollViewWillEndDragging");
}- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{NSLog(@"scrollViewDidEndDragging");
}//开始减速
- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView
{NSLog(@"scrollViewWillBeginDecelerating");
}
//减速结束 停止
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{NSLog(@"scrollViewDidEndDecelerating");}
//结束滚动动画调用
- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView
{}
//返回要缩放的视图
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{return nil;
}
//开始缩放
- (void)scrollViewWillBeginZooming:(UIScrollView *)scrollView withView:(UIView *)view
{NSLog(@"scrollViewWillBeginZooming");
}
//缩放完成
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale
{NSLog(@"scrollViewDidEndZooming");
}//是否允许滚动到顶部
- (BOOL)scrollViewShouldScrollToTop:(UIScrollView *)scrollView
{NSLog(@"scrollViewShouldScrollToTop");return YES;
}
//滑动到顶部
- (void)scrollViewDidScrollToTop:(UIScrollView *)scrollView
{NSLog(@"scrollViewDidScrollToTop");
}
- (void)didReceiveMemoryWarning {[super didReceiveMemoryWarning];// Dispose of any resources that can be recreated.
}@end