NSInteger转 Byte 数组，长度为2
NSInteger dis = (NSInteger)distanceand ;
Byte val[2] = { (dis >> 8 ) & 0xff , dis & 0x0ff};
Byte 转 NSData
NSData *data = [NSData dataWithBytes:amd length:sizeof(amd)];
线程保活
dispatch_queue_t queue = dispatch_queue_create("SENDBEAT", DISPATCH_QUEUE_SERIAL);
dispatch_async(queue, ^{
[[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:nil];
NSThread *thread = [[NSThread alloc] initWithTarget:self selector:@selector(newThread) object:nil];
[thread start];
});
- (void)newThread
{
@autoreleasepool
{
[NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(timer_callback) userInfo:nil repeats:YES];
[[NSRunLoop currentRunLoop] run];
}
}
- (void)timer_callback
{
// ZHLog(@"根本停不下来");
}
