iOS ZipArchive

一、为什么我需要解压缩文件?

1、苹果App Store的50M下载限制

        苹果公司出于流量的考虑，规定在非WIFI环境下，限制用户只能下载小于50M的应用或游戏。这样一来，对于一些数据或数据包较大的应用，我们只能尽量减小 应用二进制包的体积。而把数据打包到zip中，这样App可以通过网络下载数据包，解压出所需要的内容，而且这样也可以动态的更新内容。

2、动态更新内容

        这一点在上面已经提过了。如果应用所需要的资源需要动态更新，一种常见的做法是更新资源，重新打包，重新提交到App store，这样做你需要等待漫长的审核、上架时间。一般情况下是一周左右的时间。更好的方法是将这些资源打包放置在服务器上，App从服务器（或者云存 储）上下载，然后解压。这样做的好处显而易见，那就是可以快速更新，动态更新，不需要重新打包、上传、审核，省时省力

3、从Web上下载zip文件

        Safari和邮件程序都不支持zip的查看，通过ZipArchive你就可以为你的设备增加查看zip文件的能力了，尽管App Store里已经有一些App支持这些功能了。

二、代码实现

1、首先，下载从github上下载ZipArchive开源代码，地址如下 https://github.com/ZipArchive/ZipArchive

2、将其添加到项目中，并在链接库中添加 libz.tbd 和用于压缩测试的文件夹

3、实现代码如下

//
//  ViewController.m
//  ZipArchiveDemo
//
//  Created by 555chy on 6/23/16.
//  Copyright © 2016 555chy. All rights reserved.
//

#import "ViewController.h"
#import "SSZipArchive/SSZipArchive.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    //获取程序临时文件夹目录
    NSString *dirPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
    NSLog(@"dirPath is %@", dirPath);
    BOOL result;
    
    //压缩
    NSString *zipPath = [dirPath stringByAppendingPathComponent:@"testZip.zip"];
    NSLog(@"zipPath is %@", zipPath);
    NSString *path11 = [[NSBundle mainBundle] pathForResource:@"test11" ofType:@"txt"];
    NSString *path12 = [[NSBundle mainBundle] pathForResource:@"test12" ofType:@"txt"];
    NSString *path21 = [[NSBundle mainBundle] pathForResource:@"TestResource2/test21" ofType:@"txt"];
    NSString *path22 = [[NSBundle mainBundle] pathForResource:@"TestResource2/TestFolder/test22" ofType:@"txt"];
    NSString *folder1 = [[NSBundle mainBundle] pathForResource:@"TestResource1" ofType:nil];
    NSString *folder2 = [[NSBundle mainBundle] pathForResource:@"TestResource2" ofType:nil];
    NSLog(@"path11 = %@", path11);
    NSLog(@"path12 = %@", path12);
    NSLog(@"path21 = %@", path21);
    NSLog(@"path22 = %@", path22);
    NSLog(@"folder1 = %@", folder1);
    NSLog(@"folder2 = %@", folder2);
    
    NSArray *inputFileArray = [NSArray arrayWithObjects: path11, path12, path21, path22, nil];
    //该方法只能压缩入文件，不能存入文件夹
    //result = [SSZipArchive createZipFileAtPath:zipPath withFilesAtPaths:inputFileArray];
    //该方法只能压缩目录，keepParentDirectory表示是否将最外层的文件夹也导入进去
    result = [SSZipArchive createZipFileAtPath:zipPath withContentsOfDirectory:folder2 keepParentDirectory:YES];
    NSLog(@"zip file %@", result?@"success":@"fail");
    
    //解压
    NSString *unzipPath = [dirPath stringByAppendingPathComponent:@"testUnzip/"];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    //删除待解压目录及其所有子文件
    [fileManager removeItemAtPath:unzipPath error:nil];
    NSLog(@"unzipPath is %@", unzipPath);
    result = [SSZipArchive unzipFileAtPath:zipPath toDestination:unzipPath overwrite:YES password:nil error:nil];
    NSLog(@"unzip file %@", result?@"success":@"fail");
    
    //判断相应文件或文件夹是否存在
    BOOL isDir;
    result = [fileManager fileExistsAtPath:zipPath isDirectory:&isDir];
    NSLog(@"zip file is %@ and it's %@", result?@"exits":@"not exits", isDir?@"directory":@"file");
    result = [fileManager fileExistsAtPath:unzipPath isDirectory:&isDir];
    NSLog(@"unzip file is %@ and it's %@", result?@"exits":@"not exits", isDir?@"directory":@"file");
    //枚举路径下的文件
    NSLog(@"枚举方法1");
    //enumeratorAtPath递归获取目录下的所有文件（遇到文件夹则进入获取子文件）
    NSDirectoryEnumerator *dirEnum = [fileManager enumeratorAtPath:unzipPath];
    int i=0;
    NSString *path;
    while (path = [dirEnum nextObject]) {
        NSLog(@"unzip file %d = %@", i, path);
        i++;
    }
    NSLog(@"枚举方法2");
    //contentsOfDirectoryAtPath只能获取当前目录下的文件(或文件夹)，不递归
    NSArray *subfileArray = [fileManager contentsOfDirectoryAtPath:unzipPath error:nil];
    NSLog(@"unzip file count = %ld", [subfileArray count]);
    i=0;
    for(path in subfileArray) {
        NSLog(@"unzip file %d = %@", i, path);
        i++;
    }
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

4、运行截图