Today look at their own before the scanning, found that the lighting is not very clear, here to write again, also do the collection
#import <AVFoundation/AVFoundation.h>//Need reference framework
-(void) lightswitch:ison{
Avcapturedevice *capturedevice = [Avcapturedevice defaultdevicewithmediatype:avmediatypevideo]; Create a video-type drive object to start the flashlight
if (![ Capturedevice Hastorch]) return; Detects if there is a light
if (![ Capturedevice Hasflash]) return; Detects if there is a light
[Capturedevice Lockforconfiguration:nil];
The official explanation must be to hold a device lock--------in order to set hardware properties on an avcapturedevice, such as Focusmode and Exposuremode, Clients must first acquire a lock on the device. Clients should only, the device lock if they require settable device properties to remain unchanged. Holding the device lock unnecessarily may degrade capture quality on other applications sharing the device.
IsOn =!ison;
Capturedevice.torchmode = IsOn? Avcapturetorchmodeon:avcapturetorchmodeoff;
[Capturedevice unlockforconfiguration];
}
iOS Development Flashlight Use supplement