数码相机中，zoom就是缩放意思；也就是镜头变焦的意思，推近或者拉远焦距
/** 调节ZOOM */
- (IBAction)zoomChangeValue:(UISlider *)sender
{
NSError *error = nil;
[self.camereManager.captureDevice lockForConfiguration:&error];
if (!error) {
self.camereManager.captureDevice.videoZoomFactor = sender.value;
}else
{
NSLog(@"error = %@", error);
}
[self.camereManager.captureDevice unlockForConfiguration];
}
/** 放大缩小屏幕 */
- (IBAction)viewScaleChnageValue:(UISlider *)sender
{
self.previewView.transform = CGAffineTransformMakeScale(sender.value, sender.value);
}
/**
ZOOM:镜头变焦，推近或者拉远焦距,拍照后有效果
放大缩小屏幕：放大缩小后拍照无效果
