NSURLCache无法与UIWebVIew脱机工作

Question

我正在尝试使用来自NSURLCache的数据加载UIWebView Offline。

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // setup cache
    int cacheSizeMemory = 4*1024*1024; // 4MB
    int cacheSizeDisk = 32*1024*1024; // 32MB

    NSURLCache *urlCache = [[NSURLCache alloc] initWithMemoryCapacity:cacheSizeMemory diskCapacity:cacheSizeDisk diskPath:@"nsurlcache"];
    [NSURLCache setSharedURLCache:urlCache];
}

-(void)loadWebView{
    request = [NSURLRequest requestWithURL:myURL cachePolicy: NSURLRequestReturnCacheDataElseLoad timeoutInterval:1000];
    [self.webView loadRequest:request];
}

当我尝试离线加载UIWebView时，它调用didFailWithError而不是connectionDidFinishLoading。然而，我的缓存目录包含离线数据和资源，如css，js文件，但UIWebView无法访问它。

我已通过覆盖以下方法确认了这一点：

-(NSCachedURLResponse *)cachedResponseForRequest:(NSURLRequest *)request {
    NSCachedURLResponse *response = [super cachedResponseForRequest:request];

    if([response.data length]> 0){
       // this is called for all css , js script files
       NSLog(@"Returning data from cache");
    }
    return response;
}

此外，从缓存UIWebview返回的数据无法加载它。