导航栏返回按钮替换图片去掉文字

- (instancetype)initWithRootViewController:(UIViewController *)rootViewController

{

    self = [super initWithRootViewController:rootViewController];

    if (self) {

        // Custom initialization

        [[UINavigationBar appearance] setTintColor:oragineColorGlk1];

        UIBarButtonItem *back = [UIBarButtonItem appearance];

        UIImage *image = [UIImage imageNamed:@"return"];

        [back setBackButtonBackgroundImage:[image resizableImageWithCapInsets:UIEdgeInsetsMake(0, image.size.width, 0, 0)] forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];

        self.navigationItem.backBarButtonItem = back;

        

//        UIImage *image = [UIImage imageNamed:@"dcj60"];

//        UIGraphicsBeginImageContextWithOptions(CGSizeMake(20, 20), NO, 0.0);

//        [image drawInRect:CGRectMake(0, 0, 20, 20)];

//        UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

//        UIGraphicsEndImageContext();

//        [[UINavigationBar appearance] setBackIndicatorImage:newImage];

//        [[UINavigationBar appearance] setBackIndicatorTransitionMaskImage:newImage];

        

    }

    return self;

    

}

// 设置控制器navigationItem的backBarButtonItem显示文字为""

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated

{

    viewController.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStyleDone target:nil action:nil];

    

    [super pushViewController:viewController animated:animated];

}

xcode自动从6.0之后~leftItem距左屏幕边距有16个像素点

http://www.jianshu.com/p/457c80cbb487