如何仅动画tableViewCell一次

Question

我正在处理一个表视图，我希望在加载时将其单元格进行动画。我将alpha淡出从0中淡入1.5秒。我遇到的问题是，每次调用CellForrowat Indexpath都会使这是动画的。是否有一个好方法可以这样做，因此单元格仅一次动画，而不是每次cellforrowat indexpath都被调用？任何帮助都将受到赞赏。谢谢！

// function to configure custom table view cell 
func configCell(place: Place) {
    // hide image and label before image is loaded
    headlineImage.alpha = 0
    headlineLabel.alpha = 0
    headlineLabel.text = place.name
    // set image asynchronously
    headlineImage.sd_setImage(with: URL(string: "ImageUrl"), placeholderImage: UIImage(named: "restaurant"), options: .continueInBackground) { (_, _, _, _ ) in
            // image download complete fade in image
            print("COMPLETED SD SET IMAGE")
            UIView.animate(withDuration: 1.5, animations: {
                self.headlineImage.alpha = 1
                self.headlineLabel.alpha = 1
            })
    }
}

Answer 1

类似的东西可能会有所帮助。

创建一个全局变量

var isFirstLoad = true

然后在您的configcell方法中，将动画包装在if-block中，并将标志设置为false

func configCell(place: Place) {
    headlineLabel.text = place.name    
    if isFirstLoad == true {
        isFirstLoad = false
        headlineImage.alpha = 0
        headlineLabel.alpha = 0
        headlineImage.sd_setImage(with: URL(string: "ImageUrl"), placeholderImage: UIImage(named: "restaurant"), options: .continueInBackground) { (_, _, _, _ ) in
            print("COMPLETED SD SET IMAGE")
            UIView.animate(withDuration: 1.5, animations: {
                self.headlineImage.alpha = 1
                self.headlineLabel.alpha = 1
            })
        }
    }
}