Fix a black frame around a pdf viewer in UIWebView.

ios8-web-view-fix.m

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    // ...
    
    [self fixWebView:self.webView recursiveView:self.webView loadingFinished:NO];
}

- (void)fixWebView:(UIWebView *)webView recursiveView:(UIView *)view loadingFinished:(BOOL)finished
{
    if (finished) {
        view.alpha = 1.0;
        
        BOOL showsHorizontalScrollIndicator = webView.scrollView.showsHorizontalScrollIndicator;
        BOOL showsVerticalScrollIndicator = webView.scrollView.showsVerticalScrollIndicator;
        webView.scrollView.showsHorizontalScrollIndicator = NO;
        webView.scrollView.showsVerticalScrollIndicator = NO;
        webView.scrollView.showsHorizontalScrollIndicator = showsHorizontalScrollIndicator;
        webView.scrollView.showsVerticalScrollIndicator = showsVerticalScrollIndicator;
    } else {
        view.alpha = 0.0;
    }

    if ([NSStringFromClass([view class]) isEqualToString:@"UIWebPDFView"]) {
        view.backgroundColor = [UIColor whiteColor];
        return;
    }
    
    for (UIView *subview in [view subviews]) {
        [self fixWebView:webView recursiveView:subview loadingFinished:finished];
    }
}

- (void)fixWebView
{
    [self fixWebView:self.webView recursiveView:self.webView loadingFinished:YES];
}


#pragma mark - UIWebViewDelegate

- (void)webViewDidFinishLoad:(UIWebView *)webView
{
    [self performSelector:@selector(fixWebView) withObject:nil afterDelay:0.5];
}