iOS UIWebView通过附加字符串设置UserAgent不工作

Question

我的代码:

- (void)viewDidLoad {
[super viewDidLoad];
NSURL *url = [NSURL URLWithString:urlString];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
//    NSString *tagString = @"Mozilla/5.0 (iPhone; CPU iPhone OS 9_3_2 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Mobile/13F69/YoyaOrg-iOS";
//    NSString *tag = @"YoyaOrg-iOS";
NSString *defaultUserAgent = [self.mainWebView stringByEvaluatingJavaScriptFromString:@"navigator.userAgent"];
NSString *newUserAgent = [NSString stringWithFormat:@"%@ YoyaOrg-iOS",defaultUserAgent];
NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:newUserAgent, @"UserAgent", nil];
[[NSUserDefaults standardUserDefaults] registerDefaults:dictionary];
self.mainWebView.scrollView.bounces = NO;
[self.mainWebView loadRequest:request];
}
 NSLog(@"webUserAgent:%@",defaultUserAgent);

追加字符串"YoyaOrg-iOS"后，日志输出仍然不包含"YoyaOrg-iOS"。如果我将UserAgent替换为:

 NSString *tagString = @"Mozilla/5.0 (iPhone; CPU iPhone OS 9_3_2 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Mobile/13F69/YoyaOrg-iOS";
 NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:tagString, @"UserAgent", nil];
[[NSUserDefaults standardUserDefaults] registerDefaults:dictionary];

那么我得到的userAgent就是我想要的，我做不到，浪费了很多时间;谢谢你的回答。谢谢你的帮助!

Answer 1

在AppDelegate.swift

的didFinishLaunchingWithOptions函数中执行以下操作，以便为用户代理添加后缀

    /* changing User Agent system-wide */
    UserDefaults.standard.register(
        defaults: [
            "UserAgent" : "(UIWebView().stringByEvaluatingJavaScript(from: "navigator.userAgent;")) YOUR_POSTFIX_TO_USER_AGENT"
        ]
    )

对于全新的用户代理，您应该摆脱UIWebView().stringByEvaluatingJavaScript(from: "navigator.userAgent;")呼叫

Answer 2

我也在寻找一种改变用户代理的方法。我了解到，我应该在使用[[NSUserDefaults standardUserDefaults] registerDefaults:@{@"UserAgent":customUserAgent}];等代码实例化webview时更改用户代理，并使用NSLog(@"UserAgent = %@", [webView stringByEvaluatingJavaScriptFromString:@"navigator.userAgent"]);代码在webViewDidFinishLoad:方法中打印用户代理，以查看用户代理是否更改。

然后我发现如果我把代码[webView stringByEvaluatingJavaScriptFromString:@"navigator.userAgent"]在webview加载URL请求之前，像这样

     NSString *userAgent = [_webView stringByEvaluatingJavaScriptFromString:@"navigator.userAgent"];
    NSString *mystring = @" mystring";
    NSString *customUserAgent = [userAgent stringByAppendingString:mystring];
    [[NSUserDefaults standardUserDefaults] registerDefaults:@{@"UserAgent":customUserAgent}];

的结果是不仅用户代理是不变的，而且OC-JS的交互代码我写使用JavaScriptCore被禁用!

我找到了一种方法来解决这个问题:初始化第二个UIWebView，它什么都不做，只是为了获得默认的用户代理。下面是附加默认用户代理字符串的最终解决方案:

    _webView = [[UIWebView alloc] initWithFrame:self.view.bounds];
    _webView.scalesPageToFit = YES;
    //init another webView to get the default user agent
    NSString *userAgent = [[[UIWebView alloc] init] stringByEvaluatingJavaScriptFromString:@"navigator.userAgent"];
    NSString *mystring = @" mystring";
    NSString *customUserAgent = [userAgent stringByAppendingString:mystring];
    [[NSUserDefaults standardUserDefaults] registerDefaults:@{@"UserAgent":customUserAgent}];