objectivec 解压缩zip

1、首先引入libz.dylib框架

2、到http://code.google.com/p/ziparchive/downloads/list下载所需要的第三方文件，并将其导入到项目中。

3、解压缩ZIP文件代码如下：

    #import "ZipArchive.h"



    NSString *documentPath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"];
    ZipArchive *zipArchive = [[[ZipArchive alloc]init]autorelease];
    NSString *path = @"Lesson0";
    NSString *filePath = [[NSBundle mainBundle]pathForResource:path ofType:@"zip"];
    if ([zipArchive UnzipOpenFile:filePath]) {
        [zipArchive UnzipFileTo:documentPath overWrite:YES];
        [zipArchive UnzipCloseFile];
    }