WKWebView网页加载拦截并替换资源

1.H5加载页面缓慢，考虑使用离线化加载。 确保[低速网络]或[无网络]可网页秒开。
2.使用[NSURLProtocol]拦截 区别于uiwebview wkwebview使用如下方法拦截

[NSURLProtocol registerClass:[MyCustomProtocol class]];
    Class cls = NSClassFromString(@"WKBrowsingContextController");
    SEL sel = NSSelectorFromString(@"registerSchemeForCustomProtocol:");
    if ([(id)cls respondsToSelector:sel]) {
        [(id)cls performSelector:sel withObject:@"http"];
        [(id)cls performSelector:sel withObject:@"https"];
    }

MyCustomProtocol.h

#import 

@interface MyCustomProtocol : NSURLProtocol
@end

MyCustomProtocol.m

+ (BOOL)canInitWithRequest:(NSURLRequest *)theRequest {
    if ([theRequest.URL.absoluteString containsString:@"https://www.baidu.com/img/login_2d2c57b59121dec81f374c4fe080e9d3.png"]) {
        return YES;
    }
    return NO;
}

+ (NSURLRequest*)canonicalRequestForRequest:(NSURLRequest *)theRequest {
    return theRequest;
}

- (void)startLoading {
    NSMutableURLRequest* request = self.request.mutableCopy;
    NSURLResponse *response = [[NSURLResponse alloc] initWithURL:[request URL]
                                                        MIMEType:@"image/png"
                                           expectedContentLength:-1
                                                textEncodingName:nil];
    
    NSString *imagePath = [[NSBundle mainBundle] pathForResource:@"image1" ofType:@"png"];
    NSData *data = [NSData dataWithContentsOfFile:imagePath];
    
    [[self client] URLProtocol:self didReceiveResponse:response cacheStoragePolicy:NSURLCacheStorageNotAllowed];
    [[self client] URLProtocol:self didLoadData:data];
    [[self client] URLProtocolDidFinishLoading:self];
    NSLog(@"start loading !");
    
}

- (void)stopLoading {
    NSLog(@"something went wrong!");
}

3、使用

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    [NSURLProtocol registerClass:[MyCustomProtocol class]];
    Class cls = NSClassFromString(@"WKBrowsingContextController");
    SEL sel = NSSelectorFromString(@"registerSchemeForCustomProtocol:");
    if ([(id)cls respondsToSelector:sel]) {
        [(id)cls performSelector:sel withObject:@"http"];
        [(id)cls performSelector:sel withObject:@"https"];
    }
    
    self.webView = [[WKWebView alloc] initWithFrame:CGRectMake(0, 0, 375, 667)];
    [self.view addSubview:self.webView];
    [self.webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"https://www.baidu.com"]]];
}