先看示例圖
demo.gif
提前聲明:這個(gè)demo是仿照之前某個(gè)人用Objective-C寫的示例,點(diǎn)擊圓圈手指效果是用的一個(gè)第三方,可在demo中查看
核心技巧:
- 灰色文字點(diǎn)擊變成黑色,并且cell文字展開: cell上添加兩個(gè)一模一樣的label,一個(gè)顯示灰色,一個(gè)顯示黑色,點(diǎn)擊刷新tableView,用UIView動(dòng)畫,使一個(gè)label的alpha為1,一個(gè)label的alpha為0
由于沒有復(fù)雜邏輯,直接貼代碼了
1.控制器
import UIKit
class ViewController: UIViewController {
var modelArray : [DXCellModel] = []
lazy var tableView: UITableView = {
let table = UITableView.init(frame: CGRect.init(x: 0, y: 20, width: kScreenW, height: kScreenH-20), style: .plain)
table.sectionHeaderHeight = 0
table.sectionFooterHeight = 0
table.dataSource = self
table.delegate = self
table.separatorStyle = .none
return table
}()
override func viewDidLoad() {
super.viewDidLoad()
let strings = ["AFNetworking is a delightful networking library for iOS and Mac OS X. It's built on top of the Foundation URL Loading System, extending the powerful high-level networking abstractions built into Cocoa. It has a modular architecture with well-designed, feature-rich APIs that are a joy to use. Perhaps the most important feature of all, however, is the amazing community of developers who use and contribute to AFNetworking every day. AFNetworking powers some of the most popular and critically-acclaimed apps on the iPhone, iPad, and Mac. Choose AFNetworking for your next project, or migrate over your existing projects—you'll be happy you did!",
"歡迎使用 iPhone SE，迄今最高性能的 4 英寸 iPhone。在打造這款手機(jī)時(shí)，我們?cè)谏畹萌诵牡?4 英寸設(shè)計(jì)基礎(chǔ)上，從里到外重新構(gòu)想。它所采用的 A9 芯片，正是在 iPhone 6s 上使用的先進(jìn)芯片。1200 萬像素的攝像頭能拍出令人嘆為觀止的精彩照片和 4K 視頻，而 Live Photos 則會(huì)讓你的照片栩栩如生。這一切，成就了一款外形小巧卻異常強(qiáng)大的 iPhone。",
"★タクシー代がなかったので、家まで歩いて帰った?！铯猡肥鹿胜k生した場(chǎng)所、このレバーを引いて列車を止めてください。（丁）為了清楚地表示出一個(gè)短語或句節(jié)，其后須標(biāo)逗號(hào)。如：★この薬を、夜寢る前に一度、朝起きてからもう一度、飲んでください?！锼饯稀⒖栅蝻wぶ鳥のように、自由に生きて行きたいと思った。*****為了清楚地表示詞語與詞語間的關(guān)系，須標(biāo)逗號(hào)。標(biāo)注位置不同，有時(shí)會(huì)使句子的意思發(fā)生變化。如：★その人は大きな音にびっくりして、橫から飛び出した子供にぶつかった?！铯饯稳摔?、大きな音にびっくりして橫から飛び出した子供に、ぶつかった。",
"Two roads diverged in a yellow wood, And sorry I could not travel both And be one traveler, long I stood And looked down one as far as I could To where it bent in the undergrowth; Then took the other, as just as fair, And having perhaps the better claim, Because it was grassy and wanted wear; Though as for that the passing there Had worn them really about the same, And both that morning equally lay In leaves no step had trodden black. Oh, I kept the first for another day! Yet knowing how way leads on to way, I doubted if I should ever come back. I shall be telling this with a sigh Somewhere ages and ages hence: Two roads diverged in a wood, and I- I took the one less traveled by, And that has made all the difference. ",
"Star \"https://github.com/boai\" :)",
"AFNetworking is a delightful networking library for iOS and Mac OS X. It's built on top of the Foundation URL Loading System, extending the powerful high-level networking abstractions built into Cocoa. It has a modular architecture with well-designed, feature-rich APIs that are a joy to use. Perhaps the most important feature of all, however, is the amazing community of developers who use and contribute to AFNetworking every day. AFNetworking powers some of the most popular and critically-acclaimed apps on the iPhone, iPad, and Mac. Choose AFNetworking for your next project, or migrate over your existing projects—you'll be happy you did!",
"歡迎使用 iPhone SE，迄今最高性能的 4 英寸 iPhone。在打造這款手機(jī)時(shí)，我們?cè)谏畹萌诵牡?4 英寸設(shè)計(jì)基礎(chǔ)上，從里到外重新構(gòu)想。它所采用的 A9 芯片，正是在 iPhone 6s 上使用的先進(jìn)芯片。1200 萬像素的攝像頭能拍出令人嘆為觀止的精彩照片和 4K 視頻，而 Live Photos 則會(huì)讓你的照片栩栩如生。這一切，成就了一款外形小巧卻異常強(qiáng)大的 iPhone。",
"★タクシー代がなかったので、家まで歩いて帰った。★もし事故が発生した場(chǎng)所、このレバーを引いて列車を止めてください。（?。榱饲宄乇硎境鲆粋€(gè)短語或句節(jié)，其后須標(biāo)逗號(hào)。如：★この薬を、夜寢る前に一度、朝起きてからもう一度、飲んでください。★私は、空を飛ぶ鳥のように、自由に生きて行きたいと思った。*****為了清楚地表示詞語與詞語間的關(guān)系，須標(biāo)逗號(hào)。標(biāo)注位置不同，有時(shí)會(huì)使句子的意思發(fā)生變化。如：★その人は大きな音にびっくりして、橫から飛び出した子供にぶつかった?！铯饯稳摔?、大きな音にびっくりして橫から飛び出した子供に、ぶつかった。",
"Two roads diverged in a yellow wood, And sorry I could not travel both And be one traveler, long I stood And looked down one as far as I could To where it bent in the undergrowth; Then took the other, as just as fair, And having perhaps the better claim, Because it was grassy and wanted wear; Though as for that the passing there Had worn them really about the same, And both that morning equally lay In leaves no step had trodden black. Oh, I kept the first for another day! Yet knowing how way leads on to way, I doubted if I should ever come back. I shall be telling this with a sigh Somewhere ages and ages hence: Two roads diverged in a wood, and I- I took the one less traveled by, And that has made all the difference. ",
"Star \"https://github.com/boai\" :)"];
for i in 0..<strings.count {
let model = DXCellModel(contentStr : strings[i])
modelArray.append(model)
}
view.addSubview(self.tableView)
}
}
extension ViewController : UITableViewDataSource,UITableViewDelegate {
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.modelArray.count
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return self.modelArray[indexPath.row].cellHeigh
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = DXTableCell.cellWithTableView(tableView: tableView)
cell.model = modelArray[indexPath.row]
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let cell = tableView.cellForRow(at: indexPath) as! DXTableCell
cell.clickCell()
}
}
2.自定義cell
import UIKit
enum DXShowCellTextType {
case normal
case expand
}
class DXTableCell: UITableViewCell {
var normalLabel: UILabel!
var expandLabel: UILabel!
var superTableView: UITableView!
var cellType : DXShowCellTextType
static let identify = "cell"
class func cellWithTableView(tableView : UITableView) -> DXTableCell {
var cell = tableView.dequeueReusableCell(withIdentifier: identify) as? DXTableCell
if cell == nil {
cell = DXTableCell.init(style: .default, reuseIdentifier: identify)
cell?.superTableView = tableView
}
return cell!
}
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
self.cellType = .normal
super.init(style: style, reuseIdentifier: reuseIdentifier)
self.selectionStyle = UITableViewCellSelectionStyle.none
setupContentView()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
fileprivate func setupContentView() {
normalLabel = UILabel.init(frame: CGRect.init(x: 10, y: 10, width: kScreenW-20, height: 0))
expandLabel = UILabel.init(frame: CGRect.init(x: 10, y: 10, width: kScreenW-20, height: 0))
normalLabel?.textColor = UIColor.gray
expandLabel?.textColor = UIColor.black
normalLabel?.font = UIFont.systemFont(ofSize: 14)
expandLabel?.font = UIFont.systemFont(ofSize: 14)
normalLabel?.numberOfLines = 4
expandLabel?.numberOfLines = 0
normalLabel?.alpha = 1
expandLabel?.alpha = 0
self.contentView.addSubview(normalLabel)
self.contentView.addSubview(expandLabel)
}
var model : DXCellModel? {
didSet{
self.cellType = (model?.cellType)!
if model?.cellType == .expand {
normalLabel.alpha = 0
expandLabel.alpha = 1
normalLabel.frame = CGRect.init(x: 10, y: 10, width: kScreenW-20, height: 10)
expandLabel.frame = CGRect.init(x: 10, y: 10, width: kScreenW-20, height: 10)
}else{
normalLabel.alpha = 1
expandLabel.alpha = 0
normalLabel.frame = CGRect.init(x: 10, y: 10, width: kScreenW-20, height: 10)
expandLabel.frame = CGRect.init(x: 10, y: 10, width: kScreenW-20, height: 10)
}
normalLabel.text = model?.contentStr
expandLabel.text = model?.contentStr
normalLabel.sizeToFit()
expandLabel.sizeToFit()
}
}
open func clickCell() {
switch cellType {
case .normal:
self.cellType = .expand
self.model?.cellType = .expand
self.model?.cellHeigh = (self.model?.expandHeigh)!
cellAnimate(cellType: .normal)
self.superTableView.beginUpdates()
self.superTableView.endUpdates()
case .expand:
self.cellType = .normal
self.model?.cellType = .normal
self.model?.cellHeigh = (self.model?.normalHeigh)!
cellAnimate(cellType: .expand)
self.superTableView.beginUpdates()
self.superTableView.endUpdates()
default:
break
}
}
func cellAnimate(cellType : DXShowCellTextType){
if cellType == .normal {
UIView.animate(withDuration: 0.35, animations: {
self.expandLabel.alpha = 1
self.normalLabel.alpha = 0
})
}else{
UIView.animate(withDuration: 0.35, animations: {
self.expandLabel.alpha = 0
self.normalLabel.alpha = 1
})
}
}
}
3.模型
import UIKit
public let kScreenW = UIScreen.main.bounds.size.width
public let kScreenH = UIScreen.main.bounds.size.height
class DXCellModel: NSObject {
var contentStr : String?
var cellHeigh : CGFloat = 0.0
var normalHeigh : CGFloat = 0.0
var expandHeigh : CGFloat = 0.0
var cellType : DXShowCellTextType!
init(contentStr : String) {
self.contentStr = contentStr
self.cellType = DXShowCellTextType.normal
let height1 = DXCellModel.getSpaceLabelHeight(text: contentStr, font: 14, width: kScreenW-20.0)
let height2 = DXCellModel.getSpaceLabelHeight(text: "one", font: 14, width: kScreenW-20.0)
self.expandHeigh = height1 + 20.0
let normalTextHeight = height1 >= 4*height2 ? 4*height2 : height1
self.normalHeigh = normalTextHeight + 20
self.cellHeigh = self.normalHeigh
}
//MARK: --計(jì)算文字的高度
fileprivate class func getSpaceLabelHeight(text:String,font:CGFloat,width:CGFloat) -> CGFloat {
let paraDic:[String : Any] = [NSFontAttributeName:UIFont.systemFont(ofSize: font)]
let size = text.boundingRect(with: CGSize(width:width,height:CGFloat(MAXFLOAT)), options: .usesLineFragmentOrigin, attributes: paraDic, context: nil)
return size.height;
}
}
