iOS 通过NSURLProtocol拦截WKWebView网络请求

以前NSURLProtocol可以直接拦截UIWebView，后面升级成WKWebView发现拦截不到了

有细心爱研究的老铁发现了 [WKBrowsingContextController  registerSchemeForCustomProtocol:]  这个函数的存在

所以还是可以拦截的

直接上步骤

1.在控制器或者你喜欢的地方注册NSURLProtocol(调用以下代码)

    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"];
    }
    [NSURLProtocol registerClass:[CustomProtocol class]];

2.在你自定义的NSURLProtocol类中实现拦截

+ (BOOL)canInitWithRequest:(NSURLRequest *)request{
    
    NSString *abstring = request.URL.absoluteString;
    
    if ([abstring containsString:@"你喜欢的标记"]) {
        return YES;
    }
    
    return NO;
}
+ (NSURLRequest *)canonicalRequestForRequest:(NSURLRequest *)request
{
    return request;
}

3.在你自定义的NSURLProtocol类中拦截后替换请求的内容，以下以图片为例

- (void)startLoading{
    
    NSString *urlPathString = super.request.URL.absoluteString;
    
    if ([urlPathString containsString:@"你喜欢的标记"]) {
        
        urlPathString = [urlPathString stringByReplacingOccurrencesOfString:@"你喜欢的标记" withString:@"你喜欢的标记2"];
    }
    
    
    NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:urlPathString]];
    
    NSMutableDictionary *header = [NSMutableDictionary dictionary];
    header[@"Content-Length"] = [NSString stringWithFormat:@"%ld",imageData.length];
    
    NSHTTPURLResponse *response = [[NSHTTPURLResponse alloc] initWithURL:self.request.URL
               statusCode:200 HTTPVersion:@"1.1" headerFields:header];
    //回调
    [self.client URLProtocol:self didReceiveResponse:response cacheStoragePolicy:NSURLCacheStorageAllowed];
    [self.client URLProtocol:self didLoadData:imageData];
    [self.client URLProtocolDidFinishLoading:self];
}
- (void)stopLoading{
    NSLog(@"stop");
}