问题描述
我有使用NSFetchedResultsController
填充数据的tableView。单击单元格时,它将带您到该对象的detailViewController。并使用prepare(for :)将以下两个属性推进。
var coreDataStack: CoreDataStack!
var selectedGlaze: Glaze?
在detailView内,我有2个单元格。第一个是包含带有图像数组的scrollView的单元格:
import UIKit
protocol SwipedRecipeImageViewDelegate: class {
func recipeImageViewSwiped(_ cell: RecipePhotoTableViewCell,selectInt: Int)
}
class RecipePhotoTableViewCell: UITableViewCell,uiscrollviewdelegate {
@IBOutlet weak var scrollView: UIScrollView!
@IBOutlet weak var pageControl: UIPageControl!
// -
var imagesArray: [Data] = []
var selectedImageData: Int = 0
// -
weak var delegate: SwipedRecipeImageViewDelegate?
// -
override func awakeFromNib() {
super.awakeFromNib()
self.backgroundColor = .clear
self.selectionStyle = .none
scrollView.delegate = self
scrollView.isUserInteractionEnabled = false // Allows didSelectAtRow:
contentView.addGestureRecognizer(scrollView.panGestureRecognizer) // Allows Scrolling
}
override func layoutSubviews() {
super.layoutSubviews()
setimages()
setoffsetX(pageNumber: selectedImageData)
}
func configureCell(section: Int,row: Int,images: [RecipeImage],arrayInt: Int,delegate: SwipedRecipeImageViewDelegate) {
self.delegate = delegate
selectedImageData = arrayInt
for image in images {
guard let imageData = image.recipeImageData else { return }
imagesArray.append(imageData)
}
}
@IBAction func pageChanged(_ sender: UIPageControl) {
setoffsetX(pageNumber: sender.currentPage)
}
func setoffsetX(pageNumber: Int) {
pageControl.currentPage = pageNumber
let offsetX = contentView.bounds.width * CGFloat(pageNumber)
dispatchQueue.main.async {
UIView.animate(withDuration: 0.2,delay: 0,options: UIView.Animationoptions.curveEaSEOut,animations: {
self.scrollView.contentOffset.x = offsetX
},completion: nil)
}
}
func setimages() {
// Set Page Count:
pageControl.numberOfPages = imagesArray.count
// Set Frame For ImageViews + Scroll View:
for index in 0..<imagesArray.count {
let imageView = UIImageView()
imageView.frame.size = contentView.bounds.size
imageView.frame.origin.x = contentView.bounds.width * CGFloat(index)
imageView.image = UIImage(data: imagesArray[index])
imageView.contentMode = .scaleAspectFill
imageView.layer.masksToBounds = true // Limits Frame Size
scrollView.addSubview(imageView)
}
// Set ScrollView Size:
scrollView.contentSize = CGSize(width: (contentView.bounds.width * CGFloat(imagesArray.count)),height: contentView.bounds.height)
scrollView.delegate = self
}
// Set Page Number:
func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
let pageNumber = scrollView.contentOffset.x / scrollView.frame.size.width
self.pageControl.currentPage = Int(pageNumber)
delegate?.recipeImageViewSwiped(self,selectInt: pageControl.currentPage)
}
第二个单元格包含一个stackView及其一些标签,以显示图像显示的数据。它接受很多参数,然后设置textColor并更改一些标签。没什么好激动的,所以我没有包含代码。
DetailViewController:
override func tableView(_ tableView: UITableView,cellForRowAt indexPath: IndexPath) -> UITableViewCell {
print("cellForRowAt: ",indexPath)
switch indexPath.section {
case sectionImage: // Section 0:
guard
let images = selectedGlaze?.glazeImage,let glazeImageSelected = selectedGlaze?.glazeImageSelected // This is a Double
else { return returnDefaultCell() }
let imageArray = images.allObjects as! [RecipeImage] // Takes NSSet of relational data and changes it into an Array to be passed into the image cell.
let imageSelected = Int(glazeImageSelected) // Double Converted to Int
switch indexPath.row {
case 0:
let cell = returnRecipeImageCell()
return configureRecipeImageCell(cell: cell,for: indexPath,imagesArray: imageArray,imageSelected: imageSelected)
case 1:
let cell = returnAtmosphereCell()
return configureAtmosphereCell(cell: cell,imageSelected: imageSelected)
default: return returnDefaultCell()
}
}
}
SwipedRecipeImageViewDelegate:
func recipeImageViewSwiped(_ cell: RecipePhotoTableViewCell,selectInt: Int) {
selectedGlaze?.glazeImageSelected = Double(selectInt)
coreDataStack.saveContext()
dispatchQueue.main.async { //
self.tableView.beginUpdates() //
let row1: IndexPath = [0,1] //
self.tableView.reloadRows(at: [row1],with: .automatic) //
self.tableView.endUpdates() //
}
}
问题:
我遇到的问题是在调用recipeImageViewSwiped()
之后,用正确的信息重新加载第二个要更新的单元格。在这里看到:https://imgur.com/a/fIYfehf
dispatchQueue.main.async
块中的代码处于活动状态时,会发生这种情况。当该块被注释掉时,会发生以下情况:https://imgur.com/a/fYUVZKH-这是我所期望的。 (除了[0,1]的单元格未更新)。
具体来说,当tableView重新加载行[0,1]时,仅在该行[0,1]上调用cellForRowAt()。但是我不确定为什么[0,0]处的单元格连同图像会弹回到scrollView中显示的原始图像。
目标: 我的目标是在滚动后使带有scrollView的单元不闪烁。而且还可以保存上下文,以便对象可以保存选择数组中的哪个图像。然后使用新信息更新/重新加载第二个单元格所选图像,以便它可以正确更新其标签。
编辑:
在layoutSubviews()中删除以下内容会产生以下影响:https://imgur.com/a/vwrZfus-看起来大部分都可以正常工作。但是仍然有一个奇怪的动画。
override func layoutSubviews() {
super.layoutSubviews()
setimages()
// setoffsetX(pageNumber: selectedImageData)
}
编辑2: 设置单元格的视图似乎完全是一个问题。连同布局子视图。
编辑3:
我在Bool: hasSetLayout
内添加了一个layoutSubviews()
和一个开关,它似乎可以正常运行。 -但是,如果仍然有任何信息可以帮助我理解此问题,我将不胜感激。
var hasSetLayout = false
override func layoutSubviews() {
super.layoutSubviews()
switch hasSetLayout {
case false: setimages(selectedPhoto: selectedImageData)
default: break
}
}
解决方法
尝试重新加载没有动画的行:
import { Directive,HostBinding,AfterViewInit } from "@angular/core";
import { NgControl } from "@angular/forms";
@Directive({
selector: "[appInput]"
})
export class InputDirective implements AfterViewInit {
@HostBinding("type") readonly type = "number";
value = 5;
ngAfterViewInit(){
setTimeout(()=>{this.control.control.setValue(this.value)})
}
constructor(private control: NgControl) {
}
public increment() {
this.control.control.setValue(this.value++);
}
public decrement() {
this.control.control.setValue(this.value--);
}
}