这里的APP缓存是指Cache文件夹里的内容，iOS系统从iOS 10开始就支持系统自动清理功能了。
建议重要的内容不要放到 Cache文件夹中。

一、获取缓存

/// 获取缓存大小public static func getCacheSize() -> String {let folderPath = NSSearchPathForDirectoriesInDomains(.cachesDirectory, .userDomainMask, true).first ?? ""let manager = FileManager.defaultguard let files = manager.subpaths(atPath: folderPath)else {return "0.0B"}var folderSize = 0.0for path in files {let temPath: String = folderPath + "/" + pathlet folder = try? manager.attributesOfItem(atPath: temPath) as NSDictionaryif let c = folder?.fileSize() {folderSize += Double(Float(c))}}// 保留2位小数if folderSize > 1024 * 1024 {return String(format: "%.2f", Double(folderSize)/1024.0/1024.0) + "MB"} else if folderSize > 1024 {return String(format: "%.2f", Double(folderSize)/1024.0) + "KB"} else {return String(folderSize) + "B"}}

二、清除缓存

/// 清理缓存public static func cleanCache(_ block: (() -> Void)?) {DispatchQueue.global().async {// 文件路径let folderPath = NSSearchPathForDirectoriesInDomains(.cachesDirectory, .userDomainMask, true).first ?? ""if let files = FileManager.default.subpaths(atPath: folderPath) {for path in files {let temPath: String = folderPath + "/" + pathif FileManager.default.fileExists(atPath: temPath) == true {try? FileManager.default.removeItem(atPath: temPath)}}}// 返回主线程DispatchQueue.main.async {if let block = block {block()}}}}

三、清除网页缓存

/// 清除网页缓存public static func cleanWebCache() {let types = [WKWebsiteDataTypeMemoryCache, WKWebsiteDataTypeDiskCache]let websiteDataTypes = Set(types)let dateFrom = Date(timeIntervalSince1970: 0)WKWebsiteDataStore.default().removeData(ofTypes: websiteDataTypes, modifiedSince: dateFrom) {}}