1.计算缓存大小

    //计算缓存文件大小
    func fileSizeOfCache() -> Int {
        //取出cache文件目录
        let cachePath = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.CachesDirectory, NSSearchPathDomainMask.UserDomainMask, true).first

        //取出文件夹下文件数组
        let fileArr = NSFileManager.defaultManager().subpathsAtPath(cachePath!)
        
        var size = 0
        //快速枚举出所有文件夹计算大小
        for file in fileArr! {
            //将文件名拼接到路径中
            let path = cachePath?.stringByAppendingString("/\(file)")
            
            //取出文件属性
            let floder = try! NSFileManager.defaultManager().attributesOfItemAtPath(path!)
            
            //用元组取出文件大小属性
            for (abc, bcd) in floder {
                if abc == NSFileSize {
                    size += bcd.integerValue
                }
            }
        }
        let mm = size / 1024 / 1024
        return mm
        
    }

2.清除缓存

//清除缓存
    func clearCache() {
        
        //取出缓存文件目录
        let cachePath = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.CachesDirectory, NSSearchPathDomainMask.UserDomainMask, true).first
        
        //取出文件夹下所有文件数组
        let fileArr = NSFileManager.defaultManager().subpathsAtPath(cachePath!)
        
        //遍历删除
        for file in fileArr! {
            let path = cachePath?.stringByAppendingString("/\(file)")
            if NSFileManager.defaultManager().fileExistsAtPath(path!) {
                do {
                    try NSFileManager.defaultManager().removeItemAtPath(path!)
                }catch{}
            }
        }
        NSThread.sleepForTimeInterval(0.1)
        HHAlertView.shared().showAlertWithStyle(HHAlertStyle.Ok, inView: self.view, title: "清除缓存成功", detail: "目前剩余缓存0M", cancelButton: nil, okbutton: "确定")
    }