Question

我有一个带有UIImageView作为标题的UICollectionView（名为AddPhotoHeader）。背景设置为灰色，但是一旦在下一个控制器（名为PhotoSelectorController）中选择了图片，就应该返回带有UIImageView中图片的原始UICollectionView。

这是在AddPhotoHeader中：

var selectedImage: UIImage? {
    didSet {
        DispatchQueue.main.async {
            self.imageView.image = (self.selectedImage)!
            print("This is the selectedImage:", (self.selectedImage)!)
        }
        imageView.backgroundColor = .white
    }
}


let imageView: UIImageView = {
    let iv = UIImageView()
    iv.backgroundColor = UIColor.rgb(red: 234, green: 246, blue: 246)
    iv.contentMode = .scaleAspectFill
    iv.clipsToBounds = true
    return iv
}()

在PhotoSelectorController中，是在这里获取照片的地方：

fileprivate func fetchPhotos() {
    let allPhotos = PHAsset.fetchAssets(with: .image, options: assetsFetchOptions())

    DispatchQueue.global(qos: .background).async {
        allPhotos.enumerateObjects({ (asset, count, stop) in
            let imageManager = PHImageManager.default()
            let targetSize = CGSize(width: 200, height: 200)
            let options = PHImageRequestOptions()
            options.isSynchronous = true
            imageManager.requestImage(for: asset, targetSize: targetSize, contentMode: .aspectFit, options: options, resultHandler: { (image, info) in

                if let image = image {
                    self.images.append(image)
                    self.assets.append(asset)

                    if self.selectedImage == nil {
                        self.selectedImage = image
                    }
                }

                if count == allPhotos.count - 1 {
                    DispatchQueue.main.async {
                        self.collectionView?.reloadData()
                    }
                }

            })

        })
    }
}

用户选择照片并单击“下一步”后，将调用此函数以将图像放入AddPhotoHeader的UIImageView中。

@objc func handleNext() {
    let addPhotoHeader = AddPhotoHeader()
    addPhotoHeader.selectedImage = header?.photoImageView.image
    navigationController?.popViewController(animated: true)
}

selectedImage中的打印语句将打印出来：

This is the selectedImage: <UIImage: 0x6000028510a0>, {485, 482}

但是它只是停留为灰色矩形，AddPhotoHeader的UIImageView中没有图像显示

我觉得我在这里没有明显的步骤，但是我只是无法弄清楚。希望你能帮助我！谢谢！

设置后，即使在主线程上被调用，图像也不会显示在UIImageView中

0 个答案: