swift - 从 Firebase 下载图片

Question

请帮帮我。解释如何在单元格中设置图像。在我的数据库中，我有:标题、描述和 imageURL(来自 Firebase 存储的 url)。你能给我写一个代码并解释一下吗？

class TrainingProgram
{
    var description = ""
    var title = ""
    var imageURL = ""


    init(description: String, title: String, imageURL: String) {
        self.description = description
        self.title = title
        self.imageURL = imageURL

    }

从 firebase 获取数据的函数。

func fetchPrograms() {
        Database.database().reference().child("programs").observe(.childAdded) { (snapshot) in
            if let dict = snapshot.value as? [String: AnyObject] {
                let newTitle = dict["title"] as! String
                let newDescription = dict["description"] as! String
                let newImageURL = dict["imageURL"] as! String
                let trainingCell = TrainingProgram(description: newDescription, title: newTitle, imageURL: newImageURL)
                self.trainingPrograms.append(trainingCell)
                DispatchQueue.main.async {
                    self.collectionView.reloadData()

                }
            }
        }

    }

这就是我为我的单元格设置标题和描述的方式。

 func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
    {

        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "TrainingProgramCollectionViewCell", for: indexPath) as!  TrainingProgramCollectionViewCell

        //cell.featuredImageView.setImage(from: indexPath.item)
        cell.titleLabel.text = trainingPrograms[indexPath.item].title
        cell.descriptionLabel.text = trainingPrograms[indexPath.item].description

我在接收数据获取图片的函数中需要写些什么以及如何在单元格中设置图片

Answer 1

从此链接安装 SDWebImage pod https://github.com/SDWebImage

并在您的 CollectioView cellForRow 方法中

    var images_list = [String]()
    var imagesArray = [URL]()
    images_list.append(itemModel[indexPath.row]. imageURL)
    let storage = Storage.storage().reference()

    for x in images_list{
        print(x)

        let storageRef = storage.child("images/\(x).jpg")
        storageRef.downloadURL { (url, error) in
            if let error = error{
                print(error.localizedDescription)
            }
            else{
                imagesArray.append(url!)
            }
            if let x = images_list.last{
              cell.itemImage.sd_setImage(with: URL(string: x), placeholderImage: UIImage(named: "default"))
            }
        }
    }

完整代码

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
   {

    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "TrainingProgramCollectionViewCell", for: indexPath) as!  TrainingProgramCollectionViewCell

    //cell.featuredImageView.setImage(from: indexPath.item)
    cell.titleLabel.text = trainingPrograms[indexPath.item].title
    cell.descriptionLabel.text = trainingPrograms[indexPath.item].description

    var images_list = [String]()
    var imagesArray = [URL]()
     for x in images_list{
        print(x)

        let storageRef = storage.child("images/\(x).jpg")
        storageRef.downloadURL { (url, error) in
            if let error = error{
                print(error.localizedDescription)
            }
            else{
                imagesArray.append(url!)
            }
            if let x = images_list.last{
              cell.itemImage.sd_setImage(with: URL(string: x), placeholderImage: UIImage(named: "default"))
            }
        }
    }

 }

试试这个下载单张图片只需从 firebase 获取您的 imageUrl

 let x: String = "yourImageUrl" 
 let storageRef = storage.child("images/\(x).jpg")
        storageRef.downloadURL { (url, error) in
            if let error = error{
                print(error.localizedDescription)
            }
            else{
                imagesArray.append(url!)
            }
            if let x = images_list.last{
              cell.itemImage.sd_setImage(with: URL(string: x), placeholderImage: UIImage(named: "default"))
            }
        }