Question

我正在使用最新的SDK开发iOS应用程序。

我正在使用相机，我想进行缩放。要做到这一点，我有这个代码：

- (void) viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    [self setUpVideo];
}

- (void)setUpVideo
{
    NSLog(@"Set up video");
    UIView *view = [self videoPreviewView];
    CALayer *viewLayer = [view layer];

    [viewLayer setMasksToBounds:YES];

    AVCaptureVideoPreviewLayer *newCaptureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:DataExchanger.cameraManager.captureSession];
    CGRect bounds = [view bounds];

    UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
    CGAffineTransform t;

    if (orientation == UIInterfaceOrientationLandscapeRight)
    {
        t = CGAffineTransformMakeRotation(-M_PI_2);
        bounds = CGRectMake(bounds.origin.x, bounds.origin.y,
                                bounds.size.height, bounds.size.width);
    }

    [newCaptureVideoPreviewLayer setFrame:bounds];
    [newCaptureVideoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];

    newCaptureVideoPreviewLayer.position = CGPointMake(CGRectGetMidX(bounds), CGRectGetMidY(bounds));
    newCaptureVideoPreviewLayer.affineTransform = t;

    [viewLayer insertSublayer:newCaptureVideoPreviewLayer below:[[viewLayer sublayers] objectAtIndex:0]];

    CGAffineTransform currentTransform = CGAffineTransformIdentity;
    CGAffineTransform newTransform = CGAffineTransformScale(currentTransform, 2.0f, 2.0f);
    view.transform = newTransform;
}

但是我看到缩放图像与没有缩放的同一图像之间存在差异。在没有移动相机的情况下，当我进行变焦时，我看到中心向左下方移动。

也许我必须使用一个使用比例计算新中心的公式来移动videoView个中心。

你知道如何解决这个问题吗？

当我将变焦中心移到左下角时

0 个答案: