我有一个数组,其中包含之前选定的单元格的位置。 我想通过突出显示并选择它们(如果我单击以前选择的一个我希望它取消选择它)来向用户显示以前选择的单元格(在另一个时刻,可以是几个月前)当我弹出窗口出现,就像我在 :
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath)
我尝试了不同的事情,比如:
if (indexPath.row == 0 && indexPath.section == 0){
collectionView.selectItem(at: indexPath, animated: false, scrollPosition: UICollectionViewScrollPosition.centeredHorizontally)
}
或者:
let indexPathForFirstRow = IndexPath(item: 0, section: 0)
collectionView.cellForItem(at: indexPathForFirstRow)?.isSelected = true
但没有任何效果(或者我看不到...)
你有什么帮助吗? 谢谢!
编辑:
这是我现在做的:
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
// get a reference to our storyboard cell
var cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath as IndexPath) as! MyCollectionViewCell
// Use the outlet in our custom class to get a reference to the UILabel in the cell
if (swipeDown![2][0] == (settings!.rowSelect) && indexPath.row == 4 && indexPath.section == 4) {
let indexPathspec = IndexPath(row: 4, section: 4)
var cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPathspec) as! MyCollectionViewCell
cell.isSelected = true
cell.myLabel.text = self.items[indexPath.item]
//cell.backgroundColor = UIColor(red:0.13, green:0.37, blue:0.58, alpha:0.7)
cell.layer.borderColor = UIColor.black.cgColor
cell.layer.borderWidth = 2
print("test")
return cell
}
cell.myLabel.text = self.items[indexPath.item]
cell.backgroundColor = UIColor(red:0.13, green:0.37, blue:0.58, alpha:0.7)
cell.layer.borderColor = UIColor.black.cgColor
cell.layer.borderWidth = 2
print(cell.isSelected)
print("11")
return cell
}
在 MyCollectionViewCell 中使用这个
import UIKit
class MyCollectionViewCell: UICollectionViewCell {
@IBOutlet weak var myLabel: UILabel!
override var isSelected: Bool{
didSet{
//super.isSelected = true
self.contentView.backgroundColor = self.isSelected ? .blue : .green
}
}
}
单元格是蓝色的,所以它被选中了,但是一旦完成我就不能取消它。 启动后我选择的单元格没有问题,我可以毫无问题地选择和取消选择它们。
最佳答案
对于您要执行的操作,请使用 UICollectionViewCell
的 isSelected
属性。
关于 isSelected 的工作原理,请引用:https://medium.com/@p.gpt10/uicollectionviewcell-selection-made-easy-41dae148379d
对于最初选择一个 UICollectionViewCell
使用,
self.contentCollectionView.selectItem(at: IndexPath(row: 0, section: 0), animated: true, scrollPosition: .left)
此外,在didSelectItemAt
方法中,您不需要更改isSelected
或调用上述方法。只需引用上面的教程,您将获得所需的一切。
编辑:
class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate
{
@IBOutlet weak var aCollectionView: UICollectionView!
override func viewDidLoad()
{
super.viewDidLoad()
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
{
return 10
}
func numberOfSections(in collectionView: UICollectionView) -> Int
{
collectionView.allowsMultipleSelection = true
return 1
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
{
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "aCell", for: indexPath as IndexPath) as! myCollectionViewCell
cell.myLabel.text = "ok"
cell.isSelected = false
cell.layer.borderColor = UIColor.black.cgColor
cell.layer.borderWidth = 2
if indexPath.row == 5
{
collectionView.selectItem(at: indexPath, animated: true, scrollPosition: .left) //Add this line
cell.isSelected = true
}
return cell
}
override func didReceiveMemoryWarning()
{
super.didReceiveMemoryWarning()
}
}
class myCollectionViewCell: UICollectionViewCell
{
@IBOutlet weak var myLabel: UILabel!
override var isSelected: Bool{
didSet{
if self.isSelected
{
super.isSelected = true
self.contentView.backgroundColor = UIColor(red:0.08, green:0.28, blue:0.45, alpha:1)
}
else
{
super.isSelected = false
self.contentView.backgroundColor = UIColor(red:0.13, green:0.37, blue:0.58, alpha:0.7)
}
}
}
}
关于ios - 如何预选和突出显示 UICollectionView 中的单元格,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/45610785/