//
// ViewController.swift
// UIScrollView_Example
//
// Created by xxx on 16/4/1.
// Copyright © 2016年 xxx. All rights reserved.
//
import UIKit
class ViewController: UIViewController, UIScrollViewDelegate {
var scrollView: UIScrollView!
var childCacheView:[UIView]!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
setupView()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func setupView() {
childCacheView = []
let frame = CGRectMake(0, 0, self.view.frame.size.width, 400)
let scrollView = UIScrollView(frame: frame)
scrollView.delegate = self
self.view.addSubview(scrollView)
self.scrollView = scrollView
var offset_x: CGFloat = 0.0
let indexs = [totalCount-1, 0, 1]
for i in 0 ..< 3 {
let childView = createChildView(indexs[i])
childView.frame = CGRectMake(0.0 + offset_x, 0, self.view.frame.size.width, 400)
scrollView.addSubview(childView)
offset_x += CGFloat(self.view.frame.size.width)
childView.tag = indexs[i]
childCacheView.append(childView)
}
scrollView.contentSize = CGSizeMake(self.view.frame.size.width * 3.0, 400)
scrollView.pagingEnabled = true
scrollView.showsVerticalScrollIndicator = false
scrollView.showsHorizontalScrollIndicator = false
scrollView.setContentOffset(CGPointMake(width, 0), animated: false)
let left = UIButton(frame: CGRectMake(0, 410, 100, 40))
left.setTitle("Left", forState: UIControlState.Normal)
left.setTitleColor(UIColor.blackColor(), forState: UIControlState.Normal)
left.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(ViewController.tapLeftButton(_:))))
self.view.addSubview(left)
let right = UIButton(frame: CGRectMake(200, 410, 100, 40))
right.setTitle("Right", forState: UIControlState.Normal)
right.setTitleColor(UIColor.blackColor(), forState: UIControlState.Normal)
right.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(ViewController.tapRightButton(_:))))
self.view.addSubview(right)
}
var CGFloat {
return self.view.frame.size.width
}
func prevChildView() -> UIView {
return childCacheView[0]
}
func currChildView() -> UIView {
return childCacheView[1]
}
func nextChildView() -> UIView {
return childCacheView[2]
}
var totalCount = 8
var currentIndex: Int = 0
var urls = [
"http://pic3.zhongsou.com/image/3807f47d76cc2876255.jpg",
"http://d.hiphotos.baidu.com/zhidao/pic/item/902397dda144ad3452a5d2fad2a20cf431ad85b0.jpg",
"http://photo.niaolei.org.cn/uploads/201212/1356349545RuOuHkAy.jpg",
"http://img3.fengniao.com/forum/attachpics/155/160/6191982.jpg",
"http://img0.pconline.com.cn/pconline/1403/03/4374256_05_thumb.jpg",
"http://photo.niaolei.org.cn/uploads/201212/1356350324Tg2Ii27r.jpg",
"http://images3.qianyan.biz/qy/1/20/89/201472417401165442030.jpg",
"http://pic3.zhongsou.com/image/380bccf5f1d656ba95e.jpg"
]
@objc private func tapImage(gesture: UIGestureRecognizer) {
print("tapImage...")
}
@objc private func tapLeftButton(gesture: UIGestureRecognizer) {
print("tapLeftButton...")
var offset = scrollView.contentOffset
offset.x -= width
scrollView.setContentOffset(offset, animated: true)
}
@objc private func tapRightButton(gesture: UIGestureRecognizer) {
print("tapRightButton...")
var offset = scrollView.contentOffset
offset.x += width
scrollView.setContentOffset(offset, animated: true)
}
func scrollViewDidScroll(scrollView: UIScrollView) {
print("scrollViewDidScroll...(scrollView.contentOffset)")
}
func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
print("scrollViewDidEndDecelerating...(scrollView.contentOffset)")
computeScrollOffset()
}
func scrollViewWillBeginDragging(scrollView: UIScrollView) {
print("scrollViewWillBeginDragging...(scrollView.contentOffset)")
}
func scrollViewWillBeginDecelerating(scrollView: UIScrollView) {
print("scrollViewWillBeginDecelerating...(scrollView.contentOffset)")
}
func scrollViewDidEndScrollingAnimation(scrollView: UIScrollView) {
print("scrollViewDidEndScrollingAnimation...(scrollView.contentOffset)")
computeScrollOffset()
}
func computeScrollOffset() {
let offset_x = scrollView.contentOffset.x
let index = offset_x/width
if index == 0 {
// 向前滑动
print("向前滑动")
let currView = currChildView()
let nextView = nextChildView()
let prevView = prevChildView()
currChildView().frame.origin.x += width
prevChildView().frame.origin.x += width
nextChildView().frame.origin.x -= width * 2.0
scrollView.setContentOffset(CGPointMake(width, 0), animated: false)
childCacheView[0] = nextView
childCacheView[1] = prevView
childCacheView[2] = currView
updateChildView(childCacheView[0], currIndex: childCacheView[1].tag, increaseIndex: false)
} else if index == 2 {
// 向后滑动
print("向后滑动")
let currView = currChildView()
let nextView = nextChildView()
let prevView = prevChildView()
currChildView().frame.origin.x -= width
nextChildView().frame.origin.x -= width
prevChildView().frame.origin.x += width * 2.0
scrollView.setContentOffset(CGPointMake(width, 0), animated: false)
childCacheView[0] = currView
childCacheView[1] = nextView
childCacheView[2] = prevView
updateChildView(childCacheView[2], currIndex: childCacheView[1].tag, increaseIndex: true)
}
}
func createChildView(index: Int) -> UIView {
let imageView = UIImageView()
imageView.userInteractionEnabled = true
imageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(ViewController.tapImage(_:))))
let label = UILabel(frame: CGRectMake(0, 0, 100, 100))
label.text = "Label:(index)"
label.tag = 100
label.font = UIFont.systemFontOfSize(28.0)
label.textColor = UIColor.whiteColor()
imageView.addSubview(label)
imageView.kf_setImageWithURL(NSURL(string: urls[index])!, placeholderImage: UIImage(named: "test"))
return imageView
}
func updateChildView(childView: UIView, currIndex: Int, increaseIndex: Bool) {
var index = 0
let label = childView.viewWithTag(100) as! UILabel
if increaseIndex {
index = currIndex + 1
if index > totalCount - 1 {
index = 0
}
} else {
index = currIndex - 1
if index < 0 {
index = totalCount - 1
}
}
label.text = "Label:(index)"
childView.tag = index
(childView as! UIImageView).kf_setImageWithURL(NSURL(string: urls[index])!, placeholderImage: UIImage(named: "test"))
}
}
创建一个空白工程，直接把这段代码拷贝黏贴。
图片下载用到了onecat的Kingfisher，自行下载。
注意配置一下info.plist，添加
<key>NSAppTransportSecurity</key>
<dict>
<key>NSAllowsArbitraryLoads</key>
<true/>
</dict>
Over