- (void)setNaviBack{

    UIFont *font = [UIFont systemFontOfSize:16.f];
    //title的颜色和字体大小
    NSDictionary *textAttributes = @{
                                     
                                     NSFontAttributeName : font,
                                     
                                     NSForegroundColorAttributeName : [UIColor whiteColor]
                                     
                                     };
    
    
    UINavigationBar * navigationBar = [UINavigationBar appearance];
    navigationBar.titleTextAttributes = textAttributes;

    //导航栏的背景颜色
    navigationBar.barTintColor = MainColor;

    //返回按钮的箭头颜色

    [navigationBar setTintColor:[UIColor colorWithRed:0.984 green:0.000 blue:0.235 alpha:1.000]];

    //设置返回样式图片

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

    image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];

    navigationBar.backIndicatorImage = image;

    navigationBar.backIndicatorTransitionMaskImage = image;

    UIBarButtonItem *buttonItem = [UIBarButtonItem appearanceWhenContainedIn:[UINavigationBar class], nil];

    //设置图片与文本的偏移量

    UIOffset offset;

    offset.horizontal = - ;

    offset.vertical =  - ;

    [buttonItem setBackButtonTitlePositionAdjustment:offset forBarMetrics:UIBarMetricsDefault];

}