IOS開發，網路攝影機對焦狀態監控

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camera autofocus observer?

 I find the solution for my case to find when autofocus starts / ends. It‘s simply dealing with KVO (Key-Value Observing).

In my UIViewController:

已驗證。原地址：http://stackoverflow.com/questions/9100357/iphone-camera-autofocus-observer

// callback- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {    if( [keyPath isEqualToString:@"adjustingFocus"] ){        BOOL adjustingFocus = [ [change objectForKey:NSKeyValueChangeNewKey] isEqualToNumber:[NSNumber numberWithInt:1] ];        NSLog(@"Is adjusting focus? %@", adjustingFocus ? @"YES" : @"NO" );        NSLog(@"Change dictionary: %@", change);    }}// register observer- (void)viewWillAppear:(BOOL)animated{    AVCaptureDevice *camDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];    int flags = NSKeyValueObservingOptionNew;     [camDevice addObserver:self forKeyPath:@"adjustingFocus" options:flags context:nil];    (...)   }// unregister observer- (void)viewWillDisappear:(BOOL)animated{    AVCaptureDevice *camDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];    [camDevice removeObserver:self forKeyPath:@"adjustingFocus"];    (...)}

 

IOS開發，網路攝影機對焦狀態監控