ios导航栏透明

    self.navigationController.navigationBar.barStyle = UIBarStyleBlack;

    UIImage *headerImage = [UIImage imageNamed:@"header_newblack2"];

    

    if (floor(NSFoundationVersionNumber) <= NSFoundationVersionNumber_iOS_6_1) {

        [self.navigationController.navigationBar setTranslucent:YES];

        [self.navigationController.navigationBar setBackgroundImage:headerImage forBarMetrics: UIBarMetricsDefault];

    } else {

        [self.navigationController.navigationBar setTintColor:[UIColor whiteColor]];

        [self.navigationController.navigationBar setBackgroundImage:headerImage forBarMetrics:UIBarMetricsDefault];

        [self.navigationController.navigationBar setShadowImage:[UIImage new]];

    }

    

    self.view.backgroundColor = [UIColor whiteColor];