我发现这是在我的 UIWebView 请求中添加标头的方法 - 覆盖此委托方法:

I found that this was the way to add headers to my UIWebView request - override this delegate method:

- (BOOL) webView:(UIWebView*)webView shouldStartLoadWithRequest:(NSURLRequest*)request navigationType:(UIWebViewNavigationType) navigationType

使用此代码:

BOOL headerIsPresent = [[request allHTTPHeaderFields] objectForKey:@"my custom header"]!=nil;

if(headerIsPresent) return YES;

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    dispatch_async(dispatch_get_main_queue(), ^{
        NSURL *url = [request URL];
        NSMutableURLRequest* request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];

        // set the new headers
        for(NSString *key in [self.customHeaders allKeys]){
            [request addValue:[self.customHeaders objectForKey:key] forHTTPHeaderField:key];
        }

        // reload the request
        [self loadRequest:request];
    });
});
return NO;