dw怎么做网站,老版51个人空间找照片,企业为什么要开发网址,如何导入wordpress主题先看例子 每个弹幕的速度都是不一样的#xff0c;支持弹幕整体开始暂停。 如果弹幕实在是太多了#xff0c;有个缓冲队列#xff0c;不停的重试能否显示#xff0c;保证文字都能显示全#xff0c;并且每条都能显示。
实现是基于 CADisplayLink 实现的#xff0c;如此来…先看例子 每个弹幕的速度都是不一样的支持弹幕整体开始暂停。 如果弹幕实在是太多了有个缓冲队列不停的重试能否显示保证文字都能显示全并且每条都能显示。
实现是基于 CADisplayLink 实现的如此来说比直接搞个定时器来计算偏移丝滑简单的平移动画如下
import UIKitclass ViewController: UIViewController {let squareView UIView()override func viewDidLoad() {super.viewDidLoad()// 创建 CADisplayLink 对象let displayLink CADisplayLink(target: self, selector: #selector(update))// 将视图控制器添加到 displayLink 中displayLink.add(self, for: .common)// 设置视图属性squareView.frame CGRect(x: 50, y: 50, width: 100, height: 100)squareView.backgroundColor UIColor.red.withAlphaComponent(0.5)view.addSubview(squareView)}objc func update(_ displayLink: CADisplayLink) {// 在每一帧更新时移动视图squareView.frame.origin.x 5}
}在这个基础版本上稍微改了改就变成如下代码
import Foundation
import UIKitclass XDanMu {var row: Int 0var label: UILabel UILabel()var speed: CGFloat 0var isMe: Bool false
}class XDanMuView: UIView {var displayLink: CADisplayLink?var lineHeight: CGFloat 26var gap: CGFloat 20var minSpeed: CGFloat 1var maxSpeed: CGFloat 2var isPause: Bool falsevar danmus: [XDanMu] []var danmuQueue: [(String, Bool)] []var timer: Timer?func start() {displayLink CADisplayLink(target: self, selector: #selector(update))displayLink?.add(to: RunLoop.current, forMode: .common)timer Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(handleDanMuQueue), userInfo: nil, repeats: true)}objc func handleDanMuQueue() {if danmuQueue.isEmpty {return}let danmu danmuQueue.removeFirst()addDanMu(text: danmu.0, isMe: danmu.1)}objc func addDanMu(text: String, isMe: Bool) {let danmu XDanMu()danmu.label.frame.origin.x self.frame.size.widthdanmu.label.text textdanmu.label.sizeToFit()if isMe {danmu.label.layer.borderWidth 1}var linelasts: [XDanMu?] []let rows: Int Int(self.frame.size.height / lineHeight)for _ in 0..rows {linelasts.append(nil)}for d in danmus {if d.row linelasts.count {break}if linelasts[d.row] ! nil {let endx danmu.label.frame.origin.xlet targetx linelasts[d.row]!.label.frame.origin.xif endx targetx {linelasts[d.row] d}} else {linelasts[d.row] d}}var isMatch falsefor index in 0..linelasts.count {if let d linelasts[index] {let endx d.label.frame.origin.x d.label.frame.size.width gapif endx self.frame.size.width {danmu.row indexvar ms self.frame.size.width / endx * d.speedms CGFloat.minimum(ms, maxSpeed)danmu.speed CGFloat.random(in: minSpeed...ms)isMatch truebreak}} else {danmu.row indexdanmu.speed CGFloat.random(in: minSpeed...maxSpeed)isMatch truebreak}}if isMatch false {danmuQueue.append((text, isMe))return}danmu.label.frame.origin.y lineHeight * CGFloat(danmu.row)self.addSubview(danmu.label)self.danmus.append(danmu)}objc func update(_ displayLink: CADisplayLink) {if isPause true {return}// 在每一帧更新时移动视图for index in 0..danmus.count {let danmu danmus[index]danmu.label.frame.origin.x - danmu.speedif danmu.label.frame.origin.x -danmu.label.frame.size.width {danmu.label.removeFromSuperview()danmus.remove(at: index)break}}}
}
再找个需要使用的地方加入如下使用的代码即可实现上图的效果
override func viewDidLoad() {super.viewDidLoad()var danmuView: XDanMuView XDanMuView()danmuView.frame .init(x: 0, y: 100, width: self.view.frame.size.width, height: self.view.frame.size.height - 200)self.view.addSubview(danmuView)// 配置项danmuView.minSpeed 1danmuView.maxSpeed 2danmuView.gap 20danmuView.lineHeight 30// 启动弹幕danmuView.start()// 启动一个定时器灌弹幕timer Timer.scheduledTimer(timeInterval: 0.4, target: self, selector: #selector(addDanMu), userInfo: nil, repeats: false)
}objc func addDanMu() {let interval CGFloat.random(in: 0.3...1.0)Timer.scheduledTimer(timeInterval: interval, target: self, selector: #selector(addDanMu), userInfo: nil, repeats: false)var text for _ in 0...Int.random(in: 1...30) {text 嘿}for _ in 0...Int.random(in: 1...2) {danmuView.addDanMu(text: text, isMe: Bool.random())}
}文本的字体自行根据需求修改目前是没有增加样式跟颜色。 完整工程传送门 github gitee
