小编mar*_*ars的帖子

我使用Appdelegate中的以下代码在导航栏上为所有视图控制器设置按钮图像:

    [[UIBarButtonItem appearance] setBackButtonBackgroundImage:image forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];

现在在我的一个视图控制器中,我从库中选择一个新图像并保存.我希望只要我保存这个新图像,后退按钮的"图像"就会被这个'newimage'取代.

我尝试在每个视图控制器的viewWillAppear中跟踪代码

    [self.navigationItem.backBarButtonItem setBackButtonBackgroundImage:newimage forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];

并尝试过

 [self.navigationItem.backBarButtonItem setImage:new];

这个也是.但一切都是徒劳的.只有当我再次运行我的应用程序时才会更改图像,因此当Appdelegate中的代码被调用时.

Plz帮忙!

在完成几乎所有教程后，我仍然无法正确设置我的徽章。情况是这样的 - 当我的应用程序在后台时，我希望我的徽章增加 1。所以我使用下面的代码行

NSLog(@"In didReceiveRemoteNotification badge number is %ld",(long)[UIApplication sharedApplication].applicationIconBadgeNumber);
[UIApplication sharedApplication].applicationIconBadgeNumber += [[[userInfo objectForKey:@"aps"] objectForKey:@"badge"] integerValue];
NSLog(@"In didReceiveRemoteNotification badge number is %ld",(long)[UIApplication sharedApplication].applicationIconBadgeNumber);

这两个 NSLog 分别给我值 1 和 2。即使在设置 applicationIconBadgeNumber 之前它怎么会得到 1 ？因此，在收到单个通知时，它会显示 2 作为徽章。

为了让我的问题更清楚，我发布了在 - didReceiveRemoteNotification 中完成的整个代码

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult result))handler{

if ((application.applicationState ==  UIApplicationStateBackground)) {

    NSLog(@"===========================");
    NSLog(@"App was in BACKGROUND...");

    NSLog(@"In didReceiveRemoteNotification badge number is %ld",(long)[UIApplication sharedApplication].applicationIconBadgeNumber);
    [UIApplication sharedApplication].applicationIconBadgeNumber += [[[userInfo objectForKey:@"aps"] objectForKey:@"badge"] integerValue];
    NSLog(@"In didReceiveRemoteNotification badge number is %ld",(long)[UIApplication sharedApplication].applicationIconBadgeNumber); …