通过UIKit坐标系来全面掌握iOS中的UIScrollView组件

UIView *redView = [[UIView alloc] initWithFrame:CGRectMake(20, 20, 100, 100)];
redView.backgroundColor = [UIColor colorWithRed:0.815 green:0.007
    blue:0.105 alpha:1];
 
UIView *greenView = [[UIView alloc] initWithFrame:CGRectMake(150, 160, 150, 200)];
greenView.backgroundColor = [UIColor colorWithRed:0.494 green:0.827
    blue:0.129 alpha:1];
 
UIView *blueView = [[UIView alloc] initWithFrame:CGRectMake(40, 400, 200, 150)];
blueView.backgroundColor = [UIColor colorWithRed:0.29 green:0.564
    blue:0.886 alpha:1];
 
UIView *yellowView = [[UIView alloc] initWithFrame:CGRectMake(100, 600, 180, 150)];
yellowView.backgroundColor = [UIColor colorWithRed:0.972 green:0.905
    blue:0.109 alpha:1];
 
[mainView addSubview:redView];
[mainView addSubview:greenView];
[mainView addSubview:blueView];
[mainView addSubview:yellowView];

CGRect bounds = mainView.bounds;
bounds.origin = CGPointMake(0, 100);
mainView.bounds = bounds;

// CustomScrollView.h
@import UIKit;
 
@interface CustomScrollView : UIView
 
@property (nonatomic) CGSize contentSize;
 
@end

 
// CustomScrollView.m
#import "CustomScrollView.h"
 
@implementation CustomScrollView
 
- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self == nil) {
        return nil;
    }
    UIPanGestureRecognizer *gestureRecognizer = [[UIPanGestureRecognizer alloc]
        initWithTarget:self action:@selector(handlePanGesture:)];
    [self addGestureRecognizer:gestureRecognizer];
    return self;
}
 
- (void)handlePanGesture:(UIPanGestureRecognizer *)gestureRecognizer
{
    CGPoint translation = [gestureRecognizer translationInView:self];
    CGRect bounds = self.bounds;
 
    // Translate the view's bounds, but do not permit values that would violate contentSize
    CGFloat newBoundsOriginX = bounds.origin.x - translation.x;
    CGFloat minBoundsOriginX = 0.0;
    CGFloat maxBoundsOriginX = self.contentSize.width - bounds.size.width;
    bounds.origin.x = fmax(minBoundsOriginX, fmin(newBoundsOriginX, maxBoundsOriginX));
 
    CGFloat newBoundsOriginY = bounds.origin.y - translation.y;
    CGFloat minBoundsOriginY = 0.0;
    CGFloat maxBoundsOriginY = self.contentSize.height - bounds.size.height;
    bounds.origin.y = fmax(minBoundsOriginY, fmin(newBoundsOriginY, maxBoundsOriginY));
 
    self.bounds = bounds;
    [gestureRecognizer setTranslation:CGPointZero inView:self];
}
 
@end

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    //  创建一个滚动视图
    self.scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 64, 320, 568-64)];
    //  设置代理
    self.scrollView.delegate = self;
    self.scrollView.backgroundColor = [UIColor redColor];
    [self.view addSubview:_scrollView];
    /**
     *  CGPoint contentOffSet                       监控目前滚动的位置
     *  CGSize contentSize                          滚动范围大小(主属性)
     *  UIEdgeInsets contentInset                   视图在scrollView中的位置
     *  BOOL directionalLockEnabled                    指定控件是否只能在一个方向上滚动
     *  BOOL bounces                                控制控件遇到边框是否反弹
     *  BOOL alwaysBounceVertical                    控制垂直方向遇到边框是否反弹
     *  BOOL alwaysBounceHorizontal                    控制水平方向遇到边框是否反弹
     *  BOOL pagingEnabled                            控制控件是否整页翻动
     *  BOOL scrollEnabled                            控制控件是否能滚动
     *  BOOL showsHorizontalScrollIndicator            控制是否显示水平方向的滚动条
     *  BOOL showsVerticalScrollIndicator            控制是否显示垂直方向的滚动条
     *  UIEdgeInsets scrollIndicatorInsets            指定滚动条在scrollerView中的位置
     *  UIScrollViewIndicatorStyle indicatorStyle    设定滚动条的样式
     *  float decelerationRate                        改变scrollerView的减速点位置
     *  BOOL tracking                                监控当前目标是否正在被跟踪
     *  BOOL dragging                                监控当前目标是否正在被拖拽
     *  BOOL decelerating                            监控当前目标是否正在减速
     *  BOOL delaysContentTouches                    控制视图是否延时调用开始滚动的方法
     *  BOOL canCancelContentTouches                控制控件是否接触取消touch的事件
     *  float minimumZoomScale                        缩放的最小比例
     *  float maximumZoomScale                        缩放的最大比例
     *  float zoomScale                                设置变化比例
     *  BOOL bouncesZoom                            控制缩放的时候是否会反弹
     *  BOOL zooming                                判断控件的大小是否正在改变
     *  BOOL zoomBouncing                            判断是否正在进行缩放反弹
     *  BOOL scrollsToTop                            控制控件滚动到顶部
     */

    //  提示用户,在界面创建的时候,水平滚动条或者垂直滚动条会出现一次闪现效果
    [self.scrollView flashScrollIndicators];
    //  偏移带动画效果
    [self.scrollView setContentOffset:CGPointMake(320, 0) animated:YES];

}

#pragma mark UIScrollViewDelegate
//  只要滚动了就会触发
- (void)scrollViewDidScroll:(UIScrollView *)scrollView;
{

}

//  开始拖拽视图
// 当开始滚动视图时，执行该方法。一次有效滑动（开始滑动，滑动一小段距离，只要手指不松开，只算一次滑动），只执行一次。
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView;
{

}

// 滑动视图，当手指离开屏幕那一霎那，调用该方法。一次有效滑动，只执行一次。
// decelerate,指代，当我们手指离开那一瞬后，视图是否还将继续向前滚动（一段距离），经过测试，decelerate=YES
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate;
{

}

//  将开始降速时
- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView;
{

}

// 滚动视图减速完成，滚动将停止时，调用该方法。一次有效滑动，只执行一次。
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView;
{

}

//  滚动动画停止时执行,代码改变时出发,也就是setContentOffset改变时
// 当滚动视图动画完成后，调用该方法，如果没有动画，那么该方法将不被调用
- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView;
{

}

//  设置放大缩小的视图，要是uiscrollview的subview , 返回将要缩放的UIView对象。要执行多次
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView;
{

    return nil;
}

// 当将要开始缩放时，执行该方法。一次有效缩放，就只执行一次。
- (void)scrollViewWillBeginZooming:(UIScrollView *)scrollView withView:(UIView *)view
{
    NSLog(@"scrollViewWillBeginZooming");
}

// 当缩放结束后，并且缩放大小回到minimumZoomScale与maximumZoomScale之间后（我们也许会超出缩放范围），调用该方法。
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(double)scale;
{

}

//  如果你不是完全滚动到滚轴视图的顶部，你可以轻点状态栏，那个可视的滚轴视图会一直滚动到顶部，那是默认行为，你可以通过该方法返回NO来关闭它
- (BOOL)scrollViewShouldScrollToTop:(UIScrollView *)scrollView;
{

    return YES;
}

//  已经滑动到顶部
- (void)scrollViewDidScrollToTop:(UIScrollView *)scrollView;
{

}