設置User Agent

　　公司的前端要給項目的webview加一個區分，用來區別是iOS端訪問、android訪問還是在瀏覽器訪問的，說是要加一個User Agent ，前端根據不同信息做適配，和我說來一頭霧水，後來經過開發同事的指導和在網上查閱資料，才有了點頭緒，在這裡和大家分享一下。

一、獲取UserAgent

UIWebView方式：

UIWebView* tempWebView = [[UIWebView alloc] initWithFrame:CGRectZero];
NSString* userAgent = [tempWebView stringByEvaluatingJavaScriptFromString:@"navigator.userAgent"];
NSLog(@"UIWebView預設的userAgent = %@", userAgent);

預設UserAgent輸出：

UIWebView預設的userAgent = Mozilla/5.0 (iPhone; CPU iPhone OS 10_3_1 like Mac OS X) AppleWebKit/603.1.30 (KHTML, like Gecko) Mobile/14E304

 二、修改UserAgent

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
   UIWebView* tempWebView = [[UIWebView alloc] initWithFrame:CGRectZero];
   NSString* userAgent = [tempWebView stringByEvaluatingJavaScriptFromString:@"navigator.userAgent"];
   NSLog(@"UIWebView預設的userAgent = %@", userAgent);
   NSString *versionsss = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleShortVersionString"];;
   NSString *ua = [NSString stringWithFormat:@"%@/XYWY_YIMAI/iOS/%@", userAgent, versionsss];//自定義需要拼接的字元串
   [[NSUserDefaults standardUserDefaults] registerDefaults:@{@"UserAgent" : ua, @"User-Agent" : ua}];
}

獲取UserAgent輸出：

NSMutableURLRequest *request = .....

/** 獲取系統的UA */
NSString *sysUA = request.allHTTPHeaderFields[@"User-Agent"];

最終得到修改後的：

Mozilla/5.0 (iPhone; CPU iPhone OS 10_3_1 like Mac OS X) AppleWebKit/603.1.30 (KHTML, like Gecko) Mobile/14E304/XYWY_YIMAI/iOS/5.5