小賢的部落格

ChatGPT生成第1次的code再搭配blogger文章+微調

https://blog.csdn.net/weixin_41732253/article/details/104048437

        self.header = LottieRefreshHeader(jsonFullnName: "PullToRefres.json") {
            delegate.refresh()
        }
        
        self.scrollView.mj_header = self.header

import UIKit
import MJRefresh
import Lottie

final class LottieRefreshHeader: MJRefreshHeader {

    private let jsonFullnName: String
    private lazy var animationView: LottieAnimationView = {
        // 初始化Lottie动画视图
        let animationView = LottieAnimationView(name: jsonFullnName)
        animationView.contentMode = .scaleAspectFill
        animationView.loopMode = .playOnce
        animationView.frame = CGRect(x: 0, y: 0, width: 120, height: 120)
        return animationView
    }()
    
    init(jsonFullnName: String, refreshingBlock: @escaping MJRefreshComponentAction) {
        self.jsonFullnName = jsonFullnName
        super.init(frame: CGRect.zero) // 只能call frame，其它會Crash
        self.refreshingBlock = refreshingBlock
    }

    required init?(coder: NSCoder) {
        jsonFullnName = ""
        super.init(coder: coder)
    }
    
    override func prepare() {
        super.prepare()

        // 将动画视图添加到header的视图中
        addSubview(animationView)
    }

    override func placeSubviews() {
        super.placeSubviews()

        // 设置动画视图的位置，确保它居中显示
        animationView.center = CGPoint(x: bounds.width / 2, y: bounds.height / 2)
    }

    // 开始刷新时播放动画
    override func beginRefreshing() {
        super.beginRefreshing()
        animationView.play(fromProgress: 0, toProgress: 1, loopMode: .playOnce, completion: nil)
    }

    // 刷新结束时停止动画
    override func endRefreshing() {
        super.endRefreshing()
        animationView.stop()
    }
    
    // 使用 scrollViewContentOffsetDidChange 来监听 contentOffset 变化
    override func scrollViewContentOffsetDidChange(_ change: [AnyHashable : Any]?) {
        super.scrollViewContentOffsetDidChange(change)
        
        // 获取 scrollView 的 contentOffset，直接从 scrollView 访问
        guard let scrollView = self.scrollView else { return }
        let offset = scrollView.contentOffset
        
        // 只在下拉时更新进度，确保 y 为负值（即下拉）
        guard offset.y < 0 else { return }
        
        switch state {
            case .idle:
                // 计算下拉的进度，使用 contentOffset.y 来得出进度
                let progress = -offset.y / (scrollView.mj_h)
                
                // 限制进度范围在0到1之间
                let normalizedProgress = min(max(progress, 0), 1)
                
                // 实时更新Lottie动画的进度
                animationView.currentProgress = normalizedProgress
                
            case .pulling:
                animationView.play(fromProgress: 0, toProgress: 1, loopMode: .loop, completion: nil)
                
            case .refreshing:
                break
            case .willRefresh:
                break
            case .noMoreData:
                break
            @unknown default:
                break
        }

    }
}