清理文件緩存

類型方法 (Type Methods) + 默認參數值（Default Parameter Values）
下面默認緩存目錄為 /Library/Caches ，大家可以根據自己的緩存目錄進行更改

XCache

使用：

    //讀取緩存
    XCache.readCacheSize() //這里默認/Library/Caches目錄
    XCache.readCacheSize("/Documents") //讀取指定的目錄

    //清除緩存
    XCache.cleanCache() //默認清除/Library/Caches目錄
    XCache.cleanCache("/Documents") //清除指定的目錄
    XCache.cleanCache("/Documents") { //帶回調的清除
        print("清除的回調")
    }

XCache.swift

import UIKit

struct XCache {
    
    // MARK: - 讀取緩存大小
    static func readCacheSize(filePath: String = "/Library/Caches") -> String {
        
        let cacheFilePath = NSHomeDirectory() + filePath
        let cacheSize = forderSizeAtPath(cacheFilePath)/1024/1024
        return String(format: "%.2f", cacheSize) + "MB"
    }

   //遍歷所有目錄及子目錄
   static func forderSizeAtPath(folderPath: String) -> Double {
        let manage = NSFileManager.defaultManager()
        guard manage.fileExistsAtPath(folderPath) else { return 0 }
        let childFilePath = manage.subpathsAtPath(folderPath)!
        var fileSize:Double = 0
        for path in childFilePath {
            let fileAbsoluePath = folderPath + "/" + path
            fileSize += returnFileSzie(fileAbsoluePath)
        }
        return fileSize
    }
    
    //處理每個文件路徑下文件 —> 大小
    static func returnFileSzie(path: String) -> Double {
        let manage = NSFileManager.defaultManager()
        var fileSize:Double = 0
        do {
            fileSize = try manage.attributesOfItemAtPath(path)["NSFileSize"] as! Double
        } catch {
            print(error)
        }
        return fileSize
    }
    
    
    //MARK: - 清除緩存
    static func cleanCache(filePath: String = "/Library/Caches", competion:() -> Void = { print("清除完畢") } ) {
        
        deleteFolder(NSHomeDirectory() + filePath)
        competion()
    }
    
    //刪除文件夾的所有文件
    static func deleteFolder(folderPath: String) {
        let manage = NSFileManager.defaultManager()
        guard manage.fileExistsAtPath(folderPath) else { return }
        let childFilePath = manage.subpathsAtPath(folderPath)
        for path in childFilePath! {
            let fileAbsoluePath = folderPath + "/" + path
            deleteFile(fileAbsoluePath)
        }
    }
    
    //刪除單個文件
    static func deleteFile(path: String) {
        let manage = NSFileManager.defaultManager()
        do {
            try manage.removeItemAtPath(path)
        } catch {
            print(error)
        }
    }
}