iOS 项目一直在后台执行

时间:2024-03-24 18:36:20

我后来是这么解决不知道行不行,能够长期的在后台执行

首先我在xx-info.plist 里的 "Required background modes" 里增加"App provides Voice over IP services"

然后在delegate里增加下面代码,原理是进入后台时程序会在600秒那样结束任务,我做的就是在结束任务前新开一个任务。再结束旧任务,这样就一直的在后台执行,希望可能帮助到很多其它的人。我也查了非常久才找到这种方法的。

UIBackgroundTaskIdentifier
backgroundTaskIdentifier;
02 UIBackgroundTaskIdentifier
oldBackgroundTaskIdentifier;
03  
04 -
(BOOL) isMultitaskingSupported{
05      
06     BOOL
result = NO;
07      
08     if ([[UIDevice
currentDevice]
09           
10          respondsToSelector:@selector(isMultitaskingSupported)]){
result = [[UIDevice currentDevice] isMultitaskingSupported];
11          
12     }
13      
14     return result;
15      
16 }
17  
18 -
(
void)
timerMethod:(NSTimer *)paramSender{
19     count++;
20     if (count
% 500 == 0) {       
21         UIApplication
*application = [UIApplication sharedApplication];
22          
23         //开启一个新的后台
24          
25         backgroundTaskIdentifier
= [application beginBackgroundTaskWithExpirationHandler:^{
26    
27         }];
28         //结束旧的后台任务
29         [application
endBackgroundTask:backgroundTaskIdentifier];
30         oldBackgroundTaskIdentifier
= backgroundTaskIdentifier;
31     }
32     NSLog(@"%ld",count);
33 }
34 -
(
void)applicationDidEnterBackground:(UIApplication
*)application
35 {
36     if ([self
isMultitaskingSupported] == NO){
37          
38         return;
}
39     //开启一个后台任务
40      
41     backgroundTaskIdentifier
= [application beginBackgroundTaskWithExpirationHandler:^{       
42     }];
43     oldBackgroundTaskIdentifier
= backgroundTaskIdentifier;
44     if ([self.myTimer
isValid]) {
45         [self.myTimer
invalidate];
46     }
47     self.myTimer
= [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(timerMethod:) userInfo:nil repeats:YES];
48 }
49  
50 -
(
void)applicationWillEnterForeground:(UIApplication
*)application
51 {
52     if (backgroundTaskIdentifier
!= UIBackgroundTaskInvalid){
53         [application
endBackgroundTask:backgroundTaskIdentifier];
54         if ([self.myTimer
isValid]) {
55             [self.myTimer
invalidate];
56         }
57     }
58 }
59  
60 -
(
void)applicationWillEnterForeground:(UIApplication
*)application
61 {
62     if (backgroundTaskIdentifier
!= UIBackgroundTaskInvalid){
63         [application
endBackgroundTask:backgroundTaskIdentifier];
64         if ([self.myTimer
isValid]) {
65             [self.myTimer
invalidate];
66         }
67     }
68 }