Swift_清理缓存功能

前言

开发移动应用时，请求网络资源是再常见不过的功能。如果每次都去请求，不但浪费时间，用户体验也会变差，所以移动应用都会做离线缓存处理，其中已图片缓存最为常见。但是时间长了，离线缓存会占用大量的手机空间，所以清除缓存功能基本是移动应用开发的标配
效果图

Paste_Image.png

Paste_Image.png

代码

import UIKit

class FileTool: NSObject {
    
    static let fileManager = NSFileManager.defaultManager()
    
    /// 计算单个文件的大小
    class func fileSize(path: String) -> Double {
        if fileManager.fileExistsAtPath(path) {
            var dict = try? fileManager.attributesOfItemAtPath(path)
            if let fileSize = dict![NSFileSize] as? Int{
                return Double(fileSize) / 1024.0 / 1024.0
            }
        }
        return 0.0
    }
    
    /// 计算整个文件夹的大小
    class func folderSize(path: String) -> Double {
        var folderSize: Double = 0
        if fileManager.fileExistsAtPath(path) {
            let chilerFiles = fileManager.subpathsAtPath(path)
            for fileName in chilerFiles! {
                let tmpPath = path as NSString
                let fileFullPathName = tmpPath.stringByAppendingPathComponent(fileName)
                folderSize += FileTool.fileSize(fileFullPathName)
            }
            return folderSize
        }
        return 0
    }
    
    /// 清除文件 同步
    class func cleanFolder(path: String, complete:() -> ()) {
        let chilerFiles = self.fileManager.subpathsAtPath(path)
        for fileName in chilerFiles! {
            let tmpPath = path as NSString
            let fileFullPathName = tmpPath.stringByAppendingPathComponent(fileName)
            if self.fileManager.fileExistsAtPath(fileFullPathName) {
                do {
                    try self.fileManager.removeItemAtPath(fileFullPathName)
                } catch _ { 
                }
            }
        }
        complete()
    }
    
    /// 清除文件 异步
    class func cleanFolderAsync(path: String, complete:() -> ()) {
        let queue = dispatch_queue_create("cleanQueue", nil)
        dispatch_async(queue) { () -> Void in
            let chilerFiles = self.fileManager.subpathsAtPath(path)
            for fileName in chilerFiles! {
                let tmpPath = path as NSString
                let fileFullPathName = tmpPath.stringByAppendingPathComponent(fileName)
                if self.fileManager.fileExistsAtPath(fileFullPathName) {
                    do {
                        try self.fileManager.removeItemAtPath(fileFullPathName)
                    } catch _ {
                    }
                }
            }
            complete()
        }
    }
}

清除字符串小数点末尾的0

import UIKit

extension String {
    /// 清除字符串小数点末尾的0
    func cleanDecimalPointZear() -> String {
        
        let newStr = self as NSString
        var s = NSString()
        
        var offset = newStr.length - 1
        while offset > 0 {
            s = newStr.substringWithRange(NSMakeRange(offset, 1))
            if s.isEqualToString("0") || s.isEqualToString(".") {
                offset -= 1
            } else {
                break
            }
        }
        return newStr.substringToIndex(offset + 1)
    }
}

使用方法

// MARK: - Cache路径
public let LFBCachePath: String = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.CachesDirectory, NSSearchPathDomainMask.UserDomainMask, true).last!
 cacheNumberLabel.text = String().stringByAppendingFormat("%.2fM", FileTool.folderSize(LFBCachePath)).cleanDecimalPointZear()