在自定义框架中显示相机

Displaying camera in custom frame

我正在尝试将相机加载到自定义 CGRect 中,但我无法这样做,因为视图似乎受相机方面的限制。这是我正在使用的代码:

AVCaptureSession *session = [[AVCaptureSession alloc] init];
AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if (videoDevice)
{
    NSError *error;
    AVCaptureDeviceInput *videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:&error];
    if (!error)
    {
        if ([session canAddInput:videoInput])
        {
            [session addInput:videoInput];
            AVCaptureVideoPreviewLayer *previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:session];
            previewLayer.frame = self.view.bounds;
            CGFloat x = self.view.bounds.origin.x;
            CGFloat y = self.view.bounds.origin.y;
            CGFloat width = self.view.bounds.size.width;
            CGFloat height = 206;
            CGRect newFrame = CGRectMake(x, y, width, height);
            previewLayer.frame = newFrame;
            [self.view.layer addSublayer:previewLayer];
            [session startRunning];
        }
    }
}

这是应用程序当前显示的框架:

但是我需要这样装帧:

我不知道如何 "unlock" 相机框架或调整纵横比。是否可以在不降低图像质量的情况下获得我想要的结果,如果可以,如何实现?

在代码末尾添加这一行:

previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;