// 当Documents内文件发生改变时，启动计时器，每秒计算一次大小，当大小不发生改变时说明传输完毕，就开始刷新。
@property (nonatomic, strong) NSTimer *timer;
// 原Documents内文件大小
@property (nonatomic, assign) NSInteger filesSize;
// Documents内文件改变后的大小
@property (nonatomic, assign) NSInteger foundSize;
- (NSTimer *)timer {
if (!_timer) {
_timer = [[NSTimer alloc] init];
[_timer setFireDate:[NSDate distantFuture]];
}
return _timer;
}
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
_fileManager = [NSFileManager defaultManager];
self.timer = [NSTimer scheduledTimerWithTimeInterval:.f target:self selector:@selector(compareSize) userInfo:nil repeats:YES];
[self.timer setFireDate:[NSDate distantFuture]];
//** 监听Documents文件夹内的文件是否变化
int const folderdescriptor = open([kDocumentPath fileSystemRepresentation], O_EVTONLY);
dispatch_source_t _directorySource = dispatch_source_create(DISPATCH_SOURCE_TYPE_VNODE, folderdescriptor, DISPATCH_VNODE_WRITE, DISPATCH_TARGET_QUEUE_DEFAULT);
dispatch_source_set_event_handler(_directorySource, ^{
unsigned long const data = dispatch_source_get_data(_directorySource);
if (data & DISPATCH_VNODE_WRITE) {
// Do all the work on the main thread,
// including timer scheduling, notifications delivering
dispatch_async(dispatch_get_main_queue(), ^{
[self directoryDidChanger];
});
}
});
dispatch_source_set_cancel_handler(_directorySource, ^{
close(folderdescriptor);
});
dispatch_resume(_directorySource);
}
// 当Documengs文件夹内文件发送改变时
- (void)directoryDidChanger {
_filesSize = [self getSizeOfFilePath:kDocumentPath];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(.f * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[self.timer setFireDate:[NSDate date]];
});
}
- (void)dealloc {
// 移除计时器
[self.timer invalidate];
}
// 获取所有文件
- (NSArray *)directoryFiles {
NSArray *files = [_fileManager subpathsAtPath:kDocumentPath];
return files;
}
// 比较文件大小，以此监听是否还在传输文件
- (void)compareSize {
_foundSize = [self getSizeOfFilePath:kDocumentPath];
if (_foundSize == _filesSize) { // 如果大小没有再发生改变则刷新数据
[self.timer setFireDate:[NSDate distantFuture]];
[self selectDate]; // 开始刷新数据
}
_filesSize = _foundSize;
}