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  • IOS开发,摄像头对焦状态监控

    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:

    已验证。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"];
    
        (...)
    }
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  • 原文地址:https://www.cnblogs.com/nuanshou/p/4577053.html
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