Question

我不确定我是否出了问题但是从我能找到的例子中得知。我写了那个小小的helloworld。

#import <Foundation/Foundation.h>
#import <Foundation/NSUserNotification.h>


int main (int argc, const char * argv[])
{
    NSUserNotification *userNotification = [[NSUserNotification alloc] init];
    userNotification.title = @"Some title";
    userNotification.informativeText = @"Some text";

    [[NSUserNotificationCenter defaultUserNotificationCenter] deliverNotification:userNotification];

    return 0;
}

我用以下代码编译它：

cc -framework Foundation -o app main.m

它编译并且我可以执行它但它不会显示任何内容。由于某些原因，没有任何东西出现。我读到如果应用程序是主要角色，则可能无法显示通知。如何让它显示通知？

Answer 1

设置委托并覆盖

- (BOOL)userNotificationCenter:(NSUserNotificationCenter *)center 
                               shouldPresentNotification:(NSUserNotification *)notification {
  return YES;
}

Answer 2

我知道这是一个老问题 - 但是因为可能有人在寻找答案如何在Python＆amp; PyObjC我会在这里发布正确的语法（因为它是google搜索结果中的一个）。由于我无法评论imp的评论，我会将此作为另一个答案发布。

可以用pyobjc以这种方式在Python中做同样的事情：

def userNotificationCenter_shouldPresentNotification_(self, center, notification):
    return True

全班看起来像这样：

from Cocoa import NSObject
import objc

class MountainLionNotification(NSObject):
    """ MacOS Notifications """
    # Based on http://stackoverflow.com/questions/12202983/working-with-mountain-lions-notification-center-using-pyobjc

    def userNotificationCenter_shouldPresentNotification_(self, center, notification):
        return True

    def init(self):

        self = super(MountainLionNotification, self).init()
        if self is None: return None

        # Get objc references to the classes we need.
        self.NSUserNotification = objc.lookUpClass('NSUserNotification')
        self.NSUserNotificationCenter = objc.lookUpClass('NSUserNotificationCenter')

        return self

    def clearNotifications(self):
        """Clear any displayed alerts we have posted. Requires Mavericks."""

        NSUserNotificationCenter = objc.lookUpClass('NSUserNotificationCenter')
        NSUserNotificationCenter.defaultUserNotificationCenter().removeAllDeliveredNotifications()

    def notify(self, title="", subtitle="", text="", url=""):
        """Create a user notification and display it."""

        notification = self.NSUserNotification.alloc().init()
        notification.setTitle_(str(title))
        notification.setSubtitle_(str(subtitle))
        notification.setInformativeText_(str(text))
        # notification.setSoundName_("NSUserNotificationDefaultSoundName")
        notification.setHasActionButton_(False)
        notification.setActionButtonTitle_("View")
        # notification.setUserInfo_({"action":"open_url", "value": url})

        self.NSUserNotificationCenter.defaultUserNotificationCenter().setDelegate_(self)
        self.NSUserNotificationCenter.defaultUserNotificationCenter().scheduleNotification_(notification)

        # Note that the notification center saves a *copy* of our object.
        return notification

Answer 3

请确保为任何新通知分配新的标识符。除非使用新的标识符或用户清除其通知历史记录，否则通知只会显示一次。

NSUserNotificationCenter未显示通知

3 个答案: