iOS 修改默认 UserAgent

User-Agent（用户代理）字符串是Web浏览器用于声明自身型号版本并随HTTP请求发送给Web服务器的字符串，在Web服务器上可以获取到该字符串。

UIWebView修改UserAgent

UIWebView *webView = [[UIWebView alloc] initWithFrame:CGRectZero];
    NSString *userAgent = [webView stringByEvaluatingJavaScriptFromString:@"navigator.userAgent"];
    NSString *newUserAgent = [userAgent stringByAppendingString:@"native_iOS"];//自定义需要拼接的字符串
    NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:newUserAgent, @"UserAgent", nil];
    [[NSUserDefaults standardUserDefaults] registerDefaults:dictionary];

wkWebView修改UserAgent

__block WKWebView* web = [[WKWebView alloc]initWithFrame:CGRectZero];
    [web evaluateJavaScript:@"navigator.userAgent" completionHandler:^(id result, NSError *error) {
        NSString *userAgent = result;
        NSString *newUserAgent = [userAgent stringByAppendingString:@"/native_iOS"];//自定义需要拼接的字符串
        NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:newUserAgent, @"UserAgent", nil];
        [[NSUserDefaults standardUserDefaults] registerDefaults:dictionary];
        //如果是web是局部变量需要一些操作来延长它的生命周期，如下这样写就可以
        web = nil;
    }];