iphone - example - webview swift 4

Send custom headers with UIWebView loadRequest (2)

I want to be able to send some extra headers with my UIWebView loadRequest method.

I have tried:

NSMutableURLRequest *req = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://www.reliply.org/tools/requestheaders.php"]];
[req addValue:@"hello" forHTTPHeaderField:@"aHeader"];

[self.theWebView loadRequest:req];

I have also tried subclassing the UIWebView and intercepting the - (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType method.

In that method I had a block of code which looked like this:

NSMutableURLRequest *newRequest = [request mutableCopy];
for(NSString *key in [customHeaders allKeys]) {
    [newRequest setValue:[customHeaders valueForKey:key] forHTTPHeaderField:key];
[self loadRequest:newRequest];

But for some unknown reason it was causing the web view to not load anything (blank frame) and the error message NSURLErrorCancelled (-999) comes up (all known fixes don't fix it for me).

So I am at a loss as to what to do. How can I send a custom header along with a UIWebView request?

Many thanks!

I find another way, Can use NSURLProtocol .

-(BOOL)webView:(IMYVKWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
    NSMutableDictionary* mapObject = [NSMutableDictionary dictionary];
    mapObject[@"headers"] = request.allHTTPHeaderFields;
    mapObject[@"navigationType"] = @(navigationType);
    [webViewRequestMap setObject:mapObject forKey:request.URL.absoluteString];
    return YES;

webViewRequestMap is Static NSMutableDictionary*

in Your Custom NSURLProtocol code:

    @interface IMYCustomURLProtocol : NSURLProtocol
@implementation IMYCustomURLProtocol 
     [NSURLProtocol registerClass:self];
+ (BOOL)canInitWithRequest:(NSURLRequest *)request
    NSString* urlString = request.URL.absoluteString;
    NSDictionary* dictionary = webViewReuqestMap[urlString];
    if (dictionary)
        [webViewRequestMap removeObjectForKey:urlString];
        if ([request isKindOfClass:[NSMutableURLRequest class]]) {
           [(id)request setValue:@"HAHA" forHTTPHeaderField:@"MeiYou Co.,Ltd"];
    return NO;

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

With this code:

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;