I'm coding an iPad app, and I have to change a graphic when the day changes to Sunday.
我正在编写一个iPad应用程序,当这一天变为星期日时我必须更改图形。
My straightforward solution is to check the day in the - (void)applicationDidBecomeActive:(UIApplication *)application or -(void)viewWillAppear:(BOOL)animated methods, and set a timer like every 10 mins to check if the day have changed to Sunday while the app is active.
我直截了当的解决方案是检查 - (void)applicationDidBecomeActive:(UIApplication *)应用程序中的日期或 - (void)viewWillAppear:(BOOL)动画方法,并设置一个计时器,每10分钟检查一天是否已更改为周日,应用程序处于活动状态。
Is there another, perhaps more efficient, way to handle this?
是否还有另一种可能更有效的方法来处理这种情况?
5 个解决方案
#1
13
In your appliciation delegate, implement the following method: -(void)applicationSignificantTimeChange:(UIApplication *)application
在您的appliciation委托中,实现以下方法: - (void)applicationSignificantTimeChange:(UIApplication *)application
This method is called when the day changes, or if the device's time has been changed in the background for whatever reason (such as changes to time zone).
当白天更改时,或者由于任何原因(例如更改时区)在后台更改设备的时间时,将调用此方法。
#2
4
Another option would be to use the same two methods you mentioned, "viewWillAppear:" and "applicationDidBecomeActive:" and instead of setting a timer for every 10 minutes, just calculate the amount of time between the current time and the next Sunday. Take that time interval and use it to set a timer that will fire exactly at midnight on Sunday.
另一个选择是使用你提到的相同的两种方法,“viewWillAppear:”和“applicationDidBecomeActive:”而不是每10分钟设置一个计时器,只需计算当前时间和下一个星期日之间的时间量。取这个时间间隔并用它来设置一个定时器,该定时器将在周日的午夜准确发射。
#3
1
There's a notification for when the day changes. You could listen to it and check if it's sunday when it fires.
当天发生变化时会有通知。你可以听它并检查它是否在它发射时是星期天。
You should also check if it's sunday at launch.
您还应该检查它是否在发布时是星期天。
#4
1
What's wrong with that solution? Does it become Sunday more frequently than once every 10 minutes in some places?
这个解决方案有什么问题?在某些地方,它是否比每10分钟更频繁地变成星期天?
One thing you might want to consider: in your timer fire method, if the time is after 23:50 then reschedule the timer for sooner (i.e. around 00:00) so you're more likely to catch midnight accurately.
您可能需要考虑的一件事是:在您的计时器点火方法中,如果时间在23:50之后,则更快地重新安排计时器(即大约00:00),这样您就更有可能准确地捕捉午夜。
#5
1
This chapter might prove useful, using some type of Notification to update:
本章可能有用,使用某种类型的通知进行更新:
Although I myself ended up with the same solution you are using, it's just easier and more reliable I find.
虽然我自己最终得到了您正在使用的相同解决方案,但我发现它更简单,更可靠。
#1
13
In your appliciation delegate, implement the following method: -(void)applicationSignificantTimeChange:(UIApplication *)application
在您的appliciation委托中,实现以下方法: - (void)applicationSignificantTimeChange:(UIApplication *)application
This method is called when the day changes, or if the device's time has been changed in the background for whatever reason (such as changes to time zone).
当白天更改时,或者由于任何原因(例如更改时区)在后台更改设备的时间时,将调用此方法。
#2
4
Another option would be to use the same two methods you mentioned, "viewWillAppear:" and "applicationDidBecomeActive:" and instead of setting a timer for every 10 minutes, just calculate the amount of time between the current time and the next Sunday. Take that time interval and use it to set a timer that will fire exactly at midnight on Sunday.
另一个选择是使用你提到的相同的两种方法,“viewWillAppear:”和“applicationDidBecomeActive:”而不是每10分钟设置一个计时器,只需计算当前时间和下一个星期日之间的时间量。取这个时间间隔并用它来设置一个定时器,该定时器将在周日的午夜准确发射。
#3
1
There's a notification for when the day changes. You could listen to it and check if it's sunday when it fires.
当天发生变化时会有通知。你可以听它并检查它是否在它发射时是星期天。
You should also check if it's sunday at launch.
您还应该检查它是否在发布时是星期天。
#4
1
What's wrong with that solution? Does it become Sunday more frequently than once every 10 minutes in some places?
这个解决方案有什么问题?在某些地方,它是否比每10分钟更频繁地变成星期天?
One thing you might want to consider: in your timer fire method, if the time is after 23:50 then reschedule the timer for sooner (i.e. around 00:00) so you're more likely to catch midnight accurately.
您可能需要考虑的一件事是:在您的计时器点火方法中,如果时间在23:50之后,则更快地重新安排计时器(即大约00:00),这样您就更有可能准确地捕捉午夜。
#5
1
This chapter might prove useful, using some type of Notification to update:
本章可能有用,使用某种类型的通知进行更新:
Although I myself ended up with the same solution you are using, it's just easier and more reliable I find.
虽然我自己最终得到了您正在使用的相同解决方案,但我发现它更简单,更可靠。