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