Swift如果让ScrollView水平自动匀速无限移动如何实现可以用两个ScrollView进行无缝衔接用纯代码方式
在Swift中,可以使用两个ScrollView来实现水平自动匀速无限移动并实现无缝衔接的效果。以下是使用纯代码方式实现的示例:
首先,创建两个ScrollView并将它们添加到父视图中:
let scrollView1 = UIScrollView(frame: CGRect(x: 0, y: 0, width: self.view.frame.width, height: self.view.frame.height))
let scrollView2 = UIScrollView(frame: CGRect(x: self.view.frame.width, y: 0, width: self.view.frame.width, height: self.view.frame.height))
self.view.addSubview(scrollView1)
self.view.addSubview(scrollView2)
然后,设置ScrollView的contentSize为两倍的父视图的宽度,并将滚动条隐藏:
scrollView1.contentSize = CGSize(width: self.view.frame.width * 2, height: self.view.frame.height)
scrollView1.showsHorizontalScrollIndicator = false
scrollView2.contentSize = CGSize(width: self.view.frame.width * 2, height: self.view.frame.height)
scrollView2.showsHorizontalScrollIndicator = false
接下来,创建两个相同的内容视图,并将它们添加到ScrollView中:
let contentView1 = UIView(frame: CGRect(x: 0, y: 0, width: self.view.frame.width, height: self.view.frame.height))
let contentView2 = UIView(frame: CGRect(x: self.view.frame.width, y: 0, width: self.view.frame.width, height: self.view.frame.height))
scrollView1.addSubview(contentView1)
scrollView2.addSubview(contentView2)
然后,为内容视图添加所需的子视图或内容。在这里,可以使用UILabel来显示文本内容:
let label1 = UILabel(frame: CGRect(x: 0, y: 0, width: self.view.frame.width, height: self.view.frame.height))
label1.text = "Content 1"
label1.textAlignment = .center
contentView1.addSubview(label1)
let label2 = UILabel(frame: CGRect(x: 0, y: 0, width: self.view.frame.width, height: self.view.frame.height))
label2.text = "Content 2"
label2.textAlignment = .center
contentView2.addSubview(label2)
最后,使用Timer来触发ScrollView的无限滚动效果,每隔一段时间将ScrollView的contentOffset进行平移,并在到达边界时重置contentOffset:
var timer: Timer?
func startScrolling() {
timer = Timer.scheduledTimer(timeInterval: 0.02, target: self, selector: #selector(scrollContent), userInfo: nil, repeats: true)
}
@objc func scrollContent() {
scrollView1.contentOffset.x += 1
scrollView2.contentOffset.x += 1
if scrollView1.contentOffset.x >= self.view.frame.width {
scrollView1.contentOffset.x = 0
}
if scrollView2.contentOffset.x >= self.view.frame.width {
scrollView2.contentOffset.x = 0
}
}
// 在适当的时机停止滚动
func stopScrolling() {
timer?.invalidate()
timer = nil
}
现在,可以调用startScrolling()方法来开始滚动,调用stopScrolling()方法来停止滚动。
这样就可以实现两个ScrollView的无缝衔接并实现水平自动匀速无限移动的效果
原文地址: http://www.cveoy.top/t/topic/iT4l 著作权归作者所有。请勿转载和采集!