将UIImagePickerController叠加层置于横向中

Question

我正试图将我的叠加正确地放在横向模式上，到目前为止，这就是我所拥有的。：

所以图像出现了，但它不是填充横向上的所有屏幕......

以下是一些代码：

- (IBAction)takeSecondPhotoAction:(id)sender {

    UIImagePickerController *photoPicker = [[UIImagePickerController alloc] init];
    photoPicker.delegate = self;
    photoPicker.sourceType = UIImagePickerControllerSourceTypeCamera;

        UIImageView * overlay;


        if(self.firstPhotoImage.imageOrientation == UIImageOrientationUp || self.firstPhotoImage.imageOrientation == UIImageOrientationDown){
            overlay = [[UIImageView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
            [overlay setImage:self.firstPhotoImage];
            overlay.transform = CGAffineTransformMakeRotation(1.57);
            [overlay setContentMode:UIViewContentModeScaleAspectFit];
        }else{
            overlay = [[UIImageView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
            [overlay setContentMode:UIViewContentModeScaleAspectFit];
            [overlay setImage:self.firstPhotoImage];
        }

        overlay.alpha = alphaValue;

        photoPicker.cameraOverlayView = overlay;


    [self presentViewController:photoPicker animated:YES completion:NULL];
}

所以基本上，我首先询问图像是横向还是纵向，然后我开始填充图像，你可以在横向模式下看到，首先我旋转叠加然后我指定内容模式。

所以，我认为错误在于：[overlay setContentMode:UIViewContentModeScaleAspectFit];

有没有办法轻松妥善地完成这项工作？ 感谢