How to get the user agent on iOS?

Question

Is there a way on iOS to get the user agent of the device? I don\'t want to hard code it since I need the user agent for all devices and I need to append the user agent to a

Answer 1

A simpler way to ascertain the user agent in iOS is to get it directly from a UIWebView using the accepted answer to this SO post.But this way has two disadvantages:
1、UIWebView's first allocation may take too much time in initializing webview context.
2、the code must be executed in main thread. This may stuck main thread.
If you know the tricks of how to use private methods while avoiding the refusal of App Store Review.
You can try the following code:

    #define CALL_PRIVATE_INSTANCEMETHOD(x,sel,q)\
    {\
    SEL selector = NSSelectorFromString([NSString stringWithFormat:@"%@",@#sel]);\
    if ([x respondsToSelector:selector]) {\
    _Pragma("clang diagnostic push")\
    _Pragma("clang diagnostic ignored \"-Warc-performSelector-leaks\"")\
    q=[x performSelector:selector];\
    _Pragma("clang diagnostic pop")\
    }\
    }\

    #define CALL_PRIVATE_CLASSMETHOD_ONEPARAM(x,sel,p,q)\
    {\
    SEL selector = NSSelectorFromString([NSString stringWithFormat:@"_%@:",@#sel]);\
    if ([x respondsToSelector:selector]) {\
    _Pragma("clang diagnostic push")\
    _Pragma("clang diagnostic ignored \"-Warc-performSelector-leaks\"")\
    q=[x performSelector:selector withObject:p];\
    _Pragma("clang diagnostic pop")\
    }\
    }\

    + (NSString *)standardUserAgent{
        NSString *buildVersion = nil;
        CALL_PRIVATE_INSTANCEMETHOD([UIDevice currentDevice], buildVersion,buildVersion);

        Class webViewCls = NSClassFromString([NSString stringWithFormat:@"%@%@",@"Web",@"View"]);
        NSString *standardUA = nil;
        NSString *versions = [NSString stringWithFormat:@"Mobile/%@",buildVersion];
        CALL_PRIVATE_CLASSMETHOD_ONEPARAM(webViewCls, standardUserAgentWithApplicationName,versions,standardUA);    
        return standardUA;
    }