applicationSignificantTimeChange未被触发

Question

我已将以下代码放在appdelegate中，但尚未调用。有任何想法吗）？

 - (void)applicationSignificantTimeChange:(UIApplication *)application
        {

    NSData *data =[[NSUserDefaults standardUserDefaults] objectForKey:@"walking_coordinate"];
    NSMutableArray *walking_array = [NSKeyedUnarchiver unarchiveObjectWithData:data];

    NSData *data1 =[[NSUserDefaults standardUserDefaults] objectForKey:@"driving_coordinate"];
    NSMutableArray *driving_array = [NSKeyedUnarchiver unarchiveObjectWithData:data1];

    NSData *data2 =[[NSUserDefaults standardUserDefaults] objectForKey:@"biking_coordinate"];
    NSMutableArray *biking_array = [NSKeyedUnarchiver unarchiveObjectWithData:data2];

    [walking_array removeAllObjects];
    [driving_array removeAllObjects];
    [biking_array removeAllObjects];


}