objective-c - 如何使用 Zlib 压缩数据，而不直接使用 zlib.dylib？

Question

是否有一个类允许使用 Zlib 压缩数据，或者直接使用 zlib.dylib 是我唯一的可能性？

Answer 1

NSData+Compression 是一个易于使用的 NSData 类别实现。

• NSData+压缩.h
• NSData+压缩.m

用法：

NSData* compressed = [myData zlibDeflate];
NSData* originalData = [compressed zlibInflate];

Answer 2

这对我有用：1）基于 ZLib 的 Objective-Zip 新位置：https ://github.com/gianlucabertani/Objective-Zip

播客文件：

pod 'objective-zip', '~> 1.0'

快速示例：

#import "ViewController.h"
#import "Objective-Zip.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    NSString *docsDir;
    NSArray *dirPaths;
    dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    docsDir = [dirPaths objectAtIndex:0];
    NSString *path = [[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent:@"test.zip"]];

    OZZipFile *zipFile= [[OZZipFile alloc] initWithFileName:path
                                                       mode:OZZipFileModeCreate];
    NSString *str = @"Hello world";
    OZZipWriteStream *stream= [zipFile writeFileInZipWithName:@"file.txt"
                                             compressionLevel:OZZipCompressionLevelBest];
    [stream writeData:[str dataUsingEncoding:NSUTF8StringEncoding]];
    [stream finishedWriting];
    [zipFile close];
}

2) 其他基于 zlib 的库也运行良好。https://github.com/ZipArchive/ZipArchive

注意：有时需要将 libz.tbd（zlib.dylib 的新名称）添加到“Link Binary With Libraries”

快速示例：

#import "SSZipArchive.h"
...
- (void)viewDidLoad {
    [super viewDidLoad];
    NSString *docsDir;
    NSArray *dirPaths;
    dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    docsDir = [dirPaths objectAtIndex:0];
    NSError *error;        
    NSString *str = @"Hello world";
    NSString *fileName = [docsDir stringByAppendingPathComponent:@"test.txt"];
    BOOL succeed = [str writeToFile:fileName atomically:YES encoding:NSUTF8StringEncoding error:&error];
    if (succeed){
        NSString *path = [[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent:@"test.zip"]];
        [SSZipArchive createZipFileAtPath:path withFilesAtPaths:@[fileName]];
    }
}

Answer 3

作为替代方案，还有objective-zip，即“以面向对象友好的方式包装ZLib 和MiniZip 的小型Cocoa/Objective-C 库”。

将文件写入“.zip”存档很简单，只需执行以下代码：

ZipWriteStream *stream = [zipFile writeFileInZipWithName:@"abc.txt" compressionLevel:ZipCompressionLevelBest];
[stream writeData:abcData];
[stream finishedWriting];

该库还允许读取“.zip”文件的内容，并枚举其中包含的文件。

列出“.zip”文件的内容是通过与以下类似的代码完成的。

ZipFile *unzipFile = [[ZipFile alloc] initWithFileName:@"test.zip" mode:ZipFileModeUnzip];
NSArray *infos = [unzipFile listFileInZipInfos];

for (FileInZipInfo *info in infos) {
  NSLog(@"- %@ %@ %d (%d)", info.name, info.date, info.size, info.level);

  // Locate the file in the zip
  [unzipFile locateFileInZip:info.name];

  // Expand the file in memory
  ZipReadStream *read = [unzipFile readCurrentFileInZip];
  NSMutableData *data = [[NSMutableData alloc] initWithLength:256];
  int bytesRead = [read readDataWithBuffer:data];
  [read finishedReading];
}