NavigationController上的自定义BackButton未显示

Question

我正在尝试使用UINavigationController中的自定义后退按钮，但图片没有显示。

以下是代码：

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

如果您只想将图像显示为后退按钮，则将navigationBar的tintColor设置为清除颜色，然后将基于UIBarButtonItem的图像设置为控制器的navigationItem的backBarButtonItem。

let backButton = UIBarButtonItem(image: UIImage(named: "back"), style: .Plain, target: self, action: "back")
self.navigationController?.navigationBar.tintColor = UIColor.clearColor()
self.navigationItem.backBarButtonItem = backButton

这将使默认的后退按钮图像（＆lt;）不显示（实际上它显示但是它的颜色是清晰的，因此不可见）并且只显示背面图像。

Answer 2

也许，你应该使用UIAppearance。

喜欢这个

@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;
}

在swift中

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

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

    return true
}

Answer 3

您必须在目标视图控制器中实现这些代码行，这意味着您将推送的控制器，因为您希望自定义返回项目按钮，该按钮仅在您将视图控制器推入导航控制器堆栈时处于活动状态。你的代码适合我。

Answer 4

navigationItem.rightBarButtonItem = UIBarButtonItem(image: UIImage(named: "Back-50"), style: .Plain, target: self, action: "back")

func back(){
    self.navigationController?.popViewControllerAnimated(true)
}

Answer 5

试试这个

from django.views.decorators.csrf import csrf_exempt

愿这对你有所帮助

Answer 6

试试这个为我工作。

var BackButton : UIBarButtonItem = UIBarButtonItem(image: 
UIImage(named: "Back-50"), style: .Plain, target: self, action: "back")

self.navigationItem.leftBarButtonItem = BackButton

func back()
{
   // your backcontroller code here....
}