app delegate中的自定义导航后退按钮

Question

我在app delegate.m中使用以下代码在导航栏上设置按钮图像，但它显示3个按钮而不是一个..

[[UIBarButtonItem appearance]setBackButtonBackgroundImage:[[UIImage imageNamed:@"back_icon.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 0, 0, 0)]
                                                      forState:UIControlStateNormal
                                                    barMetrics:UIBarMetricsDefault];
[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(-100,0) forBarMetrics:UIBarMetricsDefault];

如果我使用以下代码，它会拉伸后退按钮：

[[UIBarButtonItem appearance]setBackButtonBackgroundImage:[UIImage imageNamed:@"back_icon.png"]
                                                      forState:UIControlStateNormal
                                                    barMetrics:UIBarMetricsDefault];
[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(-100,0) forBarMetrics:UIBarMetricsDefault];

Answer 1

你有UIEdgeInsetsMake值的问题，因为使用它你试图重复背景图片，试试这样

UIImage *gradientImage32 = [[UIImage imageNamed:@"selected.png"]
                                resizableImageWithCapInsets:UIEdgeInsetsMake(0, 20, 0, 20)];
[[UIBarButtonItem appearance] setBackgroundImage:gradientImage32 forState:UIControlEventTouchUpInside
                                       barMetrics:UIBarMetricsDefault];