ios调用闪光灯

1、导入相应的库文件AVFoundation

2、   

AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    if (![device hasTorch]) {
        NSLog(@"no torch");
    }else{
        [device lockForConfiguration:nil];
        if (!on) {
            [device setTorchMode: AVCaptureTorchModeOn];
        }
        else
        {
            [device setTorchMode: AVCaptureTorchModeOff];
        }
        
        [device unlockForConfiguration];
    }