IOS下利用ziparchive解压缩zip文件

ziparchive是基于开源代码”MiniZip”的zip压缩与解压的Objective-C 的Class,使用起来非常的简单
方法：从http://code.google.com/p/ziparchive/ 上下载ZipArchive.zip，解压后将代码加入工程中，并且把libz.dylib库添加到工程中
使用方法：

1. 压缩:ZipArchive可以压缩多个文件,只需要把文件一一addFileToZip即可.

 ZipArchive* zip = [[ZipArchive alloc] init];
 NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
 NSString *documentpath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
 NSString* l_zipfile = [documentpath stringByAppendingString:@"/test.zip"] ;

 NSString* image1 = [documentpath stringByAppendingString:@"/image1.jpg"] ;
 NSString* image2 = [documentpath stringByAppendingString:@"/image2.jpg"] ;

 BOOL ret = [zip CreateZipFile2:l_zipfile];
 ret = [zip addFileToZip:image1 newname:@"image1.jpg"];
 ret = [zip addFileToZip:image2 newname:@"image2.jpg"];
 if( ![zip CloseZipFile2] )
   {
      l_zipfile = @"";
   }
 [zip release];

2. 解压缩:

 ZipArchive* zip = [[ZipArchive alloc] init];
 NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
 NSString *documentpath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;

 NSString* l_zipfile = [documentpath stringByAppendingString:@"/test.zip"] ;
 NSString* unzipto = [documentpath stringByAppendingString:@"/test"] ;
 if( [zip UnzipOpenFile:l_zipfile] )
  {
    BOOL ret = [zip UnzipFileTo:unzipto overWrite:YES];
    if( NO==ret )
    {
    }
    [zip UnzipCloseFile];
  }
 [zip release];