Xcode UIWEBVIEW download , save HTML file and show

问题:

I want to download a page and show this in WEBVIEW local, but the images are missing. The images are only shown, when I'm online, in offline mode they are missing. How can I solve this? This is the code I used up until now:

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.

- (void)viewDidLoad
{

    NSURL *url = [NSURL URLWithString:@"http://livedemo00.template-help.com/wt_37587/index.html"]; 


    //[WEBVIEW loadRequest:reqURL];


    // Determile cache file path
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *filePath = [NSString stringWithFormat:@"%@/%@", [paths objectAtIndex:0],@"index.html"];   

    // Download and write to file

    NSData *urlData = [NSData dataWithContentsOfURL:url];
    [urlData writeToFile:filePath atomically:YES];

    // Load file in UIWebView
    [WEBVIEW loadRequest:[NSURLRequest requestWithURL:[NSURL fileURLWithPath:filePath]]];      



    [super viewDidLoad];
}

回答1:

I've been meaning to write this up for a few weeks now, and this question finally got me to do it. See Drop-in offline caching for UIWebView (and NSURLProtocol).

The short answer, in my experience, is that the easiest solution is to use an NSURLProtocol to intercept NSURLConnection requests (including the ones made by UIWebView) and write the results to disk. If the request is made when you're offline, just read the response from disk and replay it. This is extremely transparent to the rest of the application, and avoids all kinds of edge-cases related to subclassing NSURLCache. (For more information on how to subclass NSURLCache see Substituting local data for remote UIWebView requests on Cocoa With Love, and AFCache.)

My NSURLProtocol approach is very simple, and is not a general-purpose caching solution. It's just intended to assist a UIWebView when you're offline. But for that, I think it solves the problem well.