由于特殊需求，有时候需要给UserAgent添加相应的内容，一般都是尾部添加：
-(void)registUserAgent{
UIWebView *webView = [[UIWebView alloc] initWithFrame:CGRectZero];
NSString *oldAgent = [webView stringByEvaluatingJavaScriptFromString:@"navigator.userAgent"];
NSLog(@"old agent :%@", oldAgent);
NSString *newAgent;
if (![oldAgent hasSuffix:@"yonglian"]) {
newAgent = [oldAgent stringByAppendingString:@" yonglian"];
}else{
newAgent = oldAgent;
}
//add my info to the new agent
NSLog(@"new agent :%@", newAgent);
//regist the new agent
NSDictionary *dictionnary = [[NSDictionary alloc] initWithObjectsAndKeys:newAgent, @"UserAgent", nil];
[[NSUserDefaults standardUserDefaults] registerDefaults:dictionnary];
[[NSUserDefaults standardUserDefaults] synchronize];
}
复制代码添加最好是在程序启动的时候：
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{
}
复制代码亲测，其他方式都不管用，只能在一开始就添加。