iOS開發——應用圖標上顯示消息數量

　　iOS8以前：

UIApplication *app = [UIApplication sharedApplication];

app.applicationIconBadgeNumber = num;

 

　　iOS8及以后：

UIUserNotificationSettings *settings = [UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeBadge categories:nil];

[[UIApplication sharedApplication] registerUserNotificationSettings:settings];

　　需要先設置它，才行。而且，需要注意一點，iOS8以前，不能帶它，iOS8及以后必須帶它。

 

　　所以現在再用它的時候，需要先判斷系統版本號：

float version = [[[UIDevice currentDevice] systemVersion] floatValue];

if (version >= 8.0) {

　　 UIUserNotificationSettings *settings = [UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeBadge categories:nil];

　　[[UIApplication sharedApplication] registerUserNotificationSettings:settings];

}