我正在寻找最佳实践建议，以消除代码重复。
我有几种不同的CollectionView布局LineUps，用于将球员的位置更改到足球场上。
我可以通过按菜单中的“排队”按钮来更改阵容。
extension TimerBar: LineUpDelegate {
func lineUpSelected(value: String) {
pitchLayout = value
switch pitchLayout {
case "3-2-1":
print("Change to 3-2-1")
UIView.animate(withDuration: 0.5, animations: {
pitchCollectionView?.collectionViewLayout.invalidateLayout()
pitchCollectionView?.setCollectionViewLayout(lineup7_321, animated: false)
})
case "3-1-2":
print("Change to 3-1-2")
UIView.animate(withDuration: 0.5, animations: {
pitchCollectionView?.collectionViewLayout.invalidateLayout()
pitchCollectionView?.setCollectionViewLayout(lineup7_312, animated: false)
})
case ...
default:
print(error)
}
}
目前，setCollectionLayout方法调用了不同的布局类，但是这些文件中唯一的区别是七行代码：
if (indexPath.section == 0 && indexPath.item == 0) {attributes.center = CGPoint(x: column3, y: row15)}
if (indexPath.section == 0 && indexPath.item == 1) {attributes.center = CGPoint(x: column1, y: row3)}
if (indexPath.section == 0 && indexPath.item == 2) {attributes.center = CGPoint(x: column3, y: row3)}
if (indexPath.section == 0 && indexPath.item == 3) {attributes.center = CGPoint(x: column5, y: row3)}
if (indexPath.section == 0 && indexPath.item == 4) {attributes.center = CGPoint(x: column3, y: row45)}
if (indexPath.section == 0 && indexPath.item == 5) {attributes.center = CGPoint(x: column2, y: row6)}
if (indexPath.section == 0 && indexPath.item == 6) {attributes.center = CGPoint(x: column4, y: row6)}
由于我仍在学习Swift，所以我的问题是，在这种情况下，如何消除代码重复。什么是最佳做法解决方案？
我的自定义布局类的副本
import UIKit
class LineUp7_3_1_2: UICollectionViewLayout {
private var cellLayoutAttributes: [IndexPath: UICollectionViewLayoutAttributes] = [:]
private var center: CGPoint!
private var itemSize: CGSize!
private var radiusOfCircleViews: CGFloat!
private var numberOfItems: Int!
var sectionCount : Int?
var cellCount : Int?
// MARK: Overrides
override func prepare() {
super.prepare()
guard let collectionView = collectionView else { return }
register(PitchView.classForCoder(), forDecorationViewOfKind: decorationPitch)
register(BenchView.classForCoder(), forDecorationViewOfKind: decorationBench)
radiusOfCircleViews = CGFloat(33.5)
itemSize = CGSize(width: radiusOfCircleViews * 2, height: radiusOfCircleViews * 2)
center = CGPoint(x: (collectionView.bounds.midX), y: collectionView.bounds.midY)
sectionCount = self.collectionView?.numberOfSections
cellCount = self.collectionView?.numberOfItems(inSection: 0)
}
override var collectionViewContentSize: CGSize {
return collectionView!.bounds.size
}
override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
benchHeight = 70
pitchHeight = collectionViewContentSize.height - benchHeight!
pitchWidth = collectionViewContentSize.width
let halfCell = pitchHeight! / 12
let row1 = pitchHeight! - halfCell
let row15 = row1 - halfCell
let row2 = row15 - halfCell
let row25 = row2 - halfCell
let row3 = row25 - halfCell
let row35 = row3 - halfCell
let row4 = row35 - halfCell
let row45 = row4 - halfCell
let row5 = row45 - halfCell
let row55 = row5 - halfCell
let row6 = row55 - halfCell
let cellwidth = ((pitchWidth! - 32) / 5)
let column1 = ((pitchWidth! - 32) / 10) + 16
let column15 = ((pitchWidth! - 32) / 5) + 16
let column2 = column1 + cellwidth
let column25 = column15 + cellwidth
let column3 = column2 + cellwidth
let column35 = column25 + cellwidth
let column4 = column3 + cellwidth
let column45 = column35 + cellwidth
let column5 = column4 + cellwidth
let attributes = UICollectionViewLayoutAttributes(forCellWith: indexPath)
if (indexPath.section == 0 && indexPath.item == 0) {attributes.center = CGPoint(x: column3, y: row15)}
if (indexPath.section == 0 && indexPath.item == 1) {attributes.center = CGPoint(x: column1, y: row3)}
if (indexPath.section == 0 && indexPath.item == 2) {attributes.center = CGPoint(x: column3, y: row3)}
if (indexPath.section == 0 && indexPath.item == 3) {attributes.center = CGPoint(x: column5, y: row3)}
if (indexPath.section == 0 && indexPath.item == 4) {attributes.center = CGPoint(x: column3, y: row45)}
if (indexPath.section == 0 && indexPath.item == 5) {attributes.center = CGPoint(x: column2, y: row6)}
if (indexPath.section == 0 && indexPath.item == 6) {attributes.center = CGPoint(x: column4, y: row6)}
let itemCount = collectionView!.numberOfItems(inSection: 1)
if indexPath.section == 1 {
for i in 0..<indexPath.item + 1 {
let z = ((pitchWidth!) / (CGFloat(itemCount) + 1 ))
let x = (CGFloat(i) * z) + z
let y = pitchHeight! + (benchHeight! / 2 + 2)
attributes.center = CGPoint(x: x, y: y)
}
}
attributes.size = itemSize
return attributes
}
override func layoutAttributesForDecorationView(ofKind elementKind: String, at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
var frame = CGRect.zero
if let rows = collectionView?.numberOfItems(inSection: 0), indexPath.row < rows{
if let cellAtrtributes = layoutAttributesForItem(at: indexPath){
frame = cellAtrtributes.frame
}
}
if elementKind == decorationPitch {
let layoutAttributes = UICollectionViewLayoutAttributes(forDecorationViewOfKind: decorationPitch, with: indexPath)
layoutAttributes.frame = CGRect(x: Int(frame.minX), y: Int(frame.maxY), width: Int(frame.size.width), height: Int(frame.size.height))
layoutAttributes.zIndex = -1
return layoutAttributes }
else {
let layoutAttributes = UICollectionViewLayoutAttributes(forDecorationViewOfKind: decorationBench, with: indexPath)
layoutAttributes.frame = CGRect(x: Int(frame.minX), y: Int(frame.maxY), width: Int(frame.size.width), height: Int(frame.size.height))
layoutAttributes.zIndex = -1
return layoutAttributes
}
}
override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
guard let collectionView = collectionView else { return super.layoutAttributesForElements(in: rect) }
var visibleAttributes: [UICollectionViewLayoutAttributes] = []
for section : Int in 0..<sectionCount! {
let indexPath = IndexPath(row: 0, section: section)
if section == 0 {
let background = self.layoutAttributesForDecorationView(ofKind: decorationPitch, at: indexPath)
print("Pitch Height is \(String(describing: pitchHeight))")
print("Pitch Width is \(String(describing: pitchWidth))")
background?.frame = CGRect(x: 0, y: 0, width: pitchWidth!, height: pitchHeight!)
visibleAttributes.append(background!)
}
if section == 1 {
let bench = self.layoutAttributesForDecorationView(ofKind: decorationBench, at: indexPath)
bench?.frame = CGRect(x: 0, y: pitchHeight!, width: pitchWidth!, height: benchHeight!)
visibleAttributes.append(bench!)
}
}
for item in 0 ..< collectionView.numberOfItems(inSection: 0) {
//let header = self.layoutAttributesForSupplementaryView(ofKind: UICollectionElementKindSectionHeader, at: IndexPath(item: item, section: 0))!
let indexPath = IndexPath(item: item, section: 0)
if let attr = layoutAttributesForItem(at: indexPath) {
//visibleAttributes.append(header)
visibleAttributes.append(attr)
}
}
for item in 0 ..< collectionView.numberOfItems(inSection: 1) {
let indexPath = IndexPath(item: item, section: 1)
if let attr = layoutAttributesForItem(at: indexPath) {
visibleAttributes.append(attr)
}
}
return visibleAttributes
}
}
非常感谢您的帮助或建议。