ios - 导航 Controller 上的自定义后退按钮未出现

Question

我正在尝试在 UINavigationController 中使用自定义后退按钮，但没有显示图像。

代码如下:

self.navigationController?.navigationBar.setBackgroundImage(UIImage(), forBarMetrics: .Default)
        self.navigationController?.navigationBar.shadowImage = UIImage()
        self.navigationController?.navigationBar.translucent = true
        self.navigationController!.view.backgroundColor = UIColor.clearColor()

        self.navigationController?.navigationBar.backIndicatorImage = UIImage(named: "Back-50")
        self.navigationController?.navigationBar.backIndicatorTransitionMaskImage = UIImage(named: "Back-50")
        self.navigationItem.backBarButtonItem = UIBarButtonItem(title: "", style: UIBarButtonItemStyle.Plain, target: nil, action: nil)

我不确定这段代码出了什么问题。

Answer 1

也许，您应该使用 UIAppearance。

像这样

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    [[UINavigationBar appearance] setBackIndicatorImage: [UIImage imageNamed:@"icon-back"]];
    [[UINavigationBar appearance] setBackIndicatorTransitionMaskImage: [UIImage imageNamed:@"icon-back"]];

    return YES;
}

swift

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

    UINavigationBar.appearance().backIndicatorTransitionMaskImage = UIImage(named: "")
    UINavigationBar.appearance().backIndicatorImage = UIImage(named: "")

    return true
}