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UIwebView实现html的离线缓存_html/css_WEB-ITnose

程序员文章站 2022-05-02 18:00:04
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1、html的缓存主要采取ASIHTTPRequest的缓存策略
(1)、设置缓存策略
    //设置缓存    ASIDownloadCache *cache=[[ASIDownloadCache alloc] init];    self.myCache=cache;    //设置缓存路径    NSArray *paths =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);    NSString *documentDirectory = [paths objectAtIndex:0];    //设置缓存存放路径    [self.myCache setStoragePath:[documentDirectory stringByAppendingPathComponent:@"resource"]];    //ASIAskServerIfModifiedCachePolicy 与默认缓存大致一样,区别仅是每次请求都会 去服务器判断是否有更新    //ASIOnlyLoadIfNotCachedCachePolicy 如果有缓存在本地,不管其过期与否,总会拿来使用    //ASIFallbackToCacheIfLoadFailsCachePolicy 这个选项经常被用来与其它选项组合使用。请求失败时,如果有缓存当网络则返回本地缓存信息    [self.myCache setDefaultCachePolicy:ASIFallbackToCacheIfLoadFailsCachePolicy];      //设置缓存策略

(2)、设置异步缓存

   NSURL *Requesturl=[NSURL URLWithString:url];    ASIHTTPRequest *request=[ASIHTTPRequest requestWithURL:Requesturl];    // //获取全局变量    AppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];    // //设置缓存方式    [request setDownloadCache:appDelegate.myCache];    // //设置缓存数据存储策略,这里采取的是如果无更新或无法联网就读取缓存数据    [request setCacheStoragePolicy:ASICachePermanentlyCacheStoragePolicy];    [request setDelegate:self];     [request startAsynchronous];

html缓存完成。如想查看详细 请点击 : IOS开发网络篇之──ASIHTTPRequest详解

2、html中的图片缓存
(1)、通过正则获取html代码中的所有图片url

  NSString *urlPattern = @"UIwebView实现html的离线缓存_html/css_WEB-ITnose]+?src=[\"']?([^>'\"]+)[\"']?";    NSError *error = [NSError new];    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:urlPattern options:NSRegularExpressionCaseInsensitive error:&error ];    //match 这块内容非常强大    NSUInteger counts =[regex numberOfMatchesInString:content options:NSRegularExpressionCaseInsensitive range:NSMakeRange(0, [content length])];//匹配到的次数    if(counts > 0){        NSArray* matches = [regex matchesInString:content options:NSMatchingReportCompletion range:NSMakeRange(0, [content length])];        for (NSTextCheckingResult *match in matches) {            NSInteger count = [match numberOfRanges];//匹配项            for(NSInteger index = 0;index    

(2)、SDwebImage下载图片 、JS交互替换

 dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0ul);    dispatch_group_t group = dispatch_group_create();    for (int i = 0; i    
//设置下载完成的图片到web img- (NSString *)createSetImageUrlJavaScript:(NSString *) index imgUrl:(NSString *) url{    UIImage *myCachaImage=[[SDImageCache sharedImageCache] imageFromDiskCacheForKey:url]; NSData *imageData = UIImageJPEGRepresentation(myCachaImage,1.0); NSString *imageSource = [NSString stringWithFormat:@"data:image/jpg;base64,%@",[imageData base64Encoding]];    NSString *js = [NSString stringWithFormat:@"var imgArray = document.getElementsByTagName('img'); imgArray[%@].src=\"%@\"; " , index, imageSource];    return js;}
//32位MD5加密方式- (NSString *)getMd5_32Bit_String:(NSString *)srcString{    const char *cStr = [srcString UTF8String];    unsigned char digest[CC_MD5_DIGEST_LENGTH];    CC_MD5( cStr, strlen(cStr), digest );    NSMutableString *result = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];    for(int i = 0; i    

参考:http://bbs.csdn.net/topics/390831054