我们可以控制iphone相机的闪光灯强度吗？

Question

我们可以控制iphone相机的闪光灯强度吗？ 我正在开发用于眼睛Retina的Iphone App，并且我需要控制光强度（增加或减少闪光灯）但是我无法找到任何相关的东西我不知道Apple是否允许这样做请帮助我找到这个解决方案。谢谢。

AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if ([device hasTorch]) {
  [device lockForConfiguration:nil];
  [device setTorchMode:AVCaptureTorchModeOff];
  [device unlockForConfiguration];
}

我正在使用此代码来启用闪光灯。 我设法通过添加这些代码来解决这个问题。

UISlider *slider = [[UISlider alloc] initWithFrame:CGRectMake(20.0f, 20.0f, 280.0f, 40.0f)];
    slider.maximumValue = 1.0f;
    slider.minimumValue = 0.2f;
    [slider setContinuous:YES];
    [slider addTarget:self action:@selector(sliderDidChange:) forControlEvents:UIControlEventValueChanged];
    [self.view addSubview:slider];

    AVCaptureDevice *flashLight = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    if([flashLight isTorchAvailable] && [flashLight isTorchModeSupported:AVCaptureTorchModeOn])
    {
        BOOL success = [flashLight lockForConfiguration:nil];
        if(success)
        {
            [flashLight setTorchMode:AVCaptureTorchModeOn];
            [flashLight unlockForConfiguration];
        }
    }
And then write this method somewhere in your code
- (void)sliderDidChange:(UISlider *)slider
{
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    [device lockForConfiguration:nil];
    [device setTorchModeOnWithLevel:slider.value error:NULL];
    [device unlockForConfiguration];
}