iOS 修改通用的返回图片

    UIImage *backButtonImage = [[UIImage imageNamed:@"icon_sys_fanhihei"] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 15, 0, 0)];//15为图片宽度＋间距    [[UIBarButtonItem appearance] setBackButtonBackgroundImage:backButtonImage forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];    //将返回按钮的文字position设置不在屏幕上显示//    [[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(NSIntegerMin, NSIntegerMin) forBarMetrics:UIBarMetricsDefault];