IOS 状态栏保持黑底白字

plist里面增加ViewControllerBasedStatusBarAppearance ＝NO

然后在AppDelegate 加入

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >=7) {
        
         [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];

}