ios開發之手電使用補充

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今天看自己之前的scanning,發現對於照明說的不是很清楚,這裡重新寫一次,也做收藏

#import <AVFoundation/AVFoundation.h>   //需要引用架構

- (void)lightSwitch:isOn{

AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; //建立Video類型的驅動對象用於啟動手電筒

   if (![captureDevice hasTorch]) return;  //檢測是否有燈光

    if(![captureDevice hasFlash])  return; //檢測是否有燈光

    [captureDevice lockForConfiguration:nil];

//  官方解釋,必須要持一個裝置鎖  --------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 hold the device lock if they require settable device properties to remain unchanged. Holding the device lock unnecessarily may degrade capture quality in other applications sharing the device.

    isOn = !isOn;

    captureDevice.torchMode = isOn? AVCaptureTorchModeOn:AVCaptureTorchModeOff;

    [captureDevice unlockForConfiguration];

}

ios開發之手電使用補充