我试图在UITableView
中的每个项目旁边添加一个彩色竖条,但不确定实现这一目标的正确和最有效的方法。是否有可能重用相同的UITableViewCell
来以不同的方式给条形图着色?由于项目D有3个垂直条,项目F和G有2个垂直彩色条,我需要创建不同的自定义UITableViewCell
吗?是否可以使用而不是UIImageView
?仅仅为了纯色而使用图像似乎是非常低效的。如何使用Swift 4.0以编程方式完成此操作?我已经看过这个了:
但这并不能解决问题。
我还希望满足以下条件:
项目A、B、C、E和H的宽度为20,UITableViewCell
.
UITableViewCell
的高度为20。每个彩色垂直条的宽度为4,包括每个彩色垂直条之间的白色条。UITableViewCell
。每条竖条颜色为8宽,中间留4条,背景颜色为白色。视图控制器
import UIKit
class MyViewController: UIViewController {
let cellId = "cellId"
lazy var tableView: UITableView = {
let tableView = UITableView()
tableView.delegate = self
tableView.dataSource = self
tableView.register(UITableViewCell.self, forCellReuseIdentifier: cellId)
tableView.translatesAutoresizingMaskIntoConstraints = false
return tableView
}()
var allItems = ["Item A", "Item B", "Item C", "Item D", "Item E", "Item F", "Item G", "Item H"]
override func viewDidLoad() {
super.viewDidLoad()
self.title = "Hello World"
self.tableView.register(CustomCell.self as AnyClass, forCellReuseIdentifier: "Cell")
view.addSubview(tableView)
let constraints = [
tableView.topAnchor.constraint(equalTo: view.topAnchor),
tableView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
tableView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
]
NSLayoutConstraint.activate(constraints)
}
}
extension MyViewController: UITableViewDelegate, UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return allItems.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
var cell:CustomCell? = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as? CustomCell
if cell == nil {
cell = CustomCell(style: UITableViewCellStyle.default, reuseIdentifier: "Cell")
}
cell?.textLabel?.text = allItems[indexPath.row]
return cell!
}
}
自定义UITableViewCell
import Foundation
import UIKit
class CustomCell: UITableViewCell {
enum BarStyle {
case single
case double
case triple
}
var barStyle: BarStyle = .single {
didSet {
switch barStyle {
case .single:
bar.style = .single
case .double:
bar.style = .double
case .triple:
bar.style = .triple
}
}
}
var barColor = UIColor.black {
didSet {
bar.color = barColor
}
}
private let bar = VerticalBarView(frame: .zero)
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
commonInit()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
commonInit()
}
func commonInit() {
self.contentView.addSubview(bar)
// setup constraints as needed so bar is positioned and sized properly
let constraints = [
VerticalBarView.topAnchor.constraint(equalTo: CustomCell.topAnchor),
VerticalBarView.bottomAnchor.constraint(equalTo: CustomCell.bottomAnchor)
]
NSLayoutConstraint.activate(constraints)
}
}
Plist文件(Items.plist)
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<array>
<dict>
<key>name</key>
<string>Item A</string>
<key>style</key>
<string>single</string>
<key>colour</key>
<string>A90F32</string>
</dict>
<dict>
<key>name</key>
<string>Item B</string>
<key>style</key>
<string>single</string>
<key>colour</key>
<string>427B7B</string>
</dict>
<dict>
<key>name</key>
<string>Item C</string>
<key>style</key>
<string>single</string>
<key>colour</key>
<string>C9910D</string>
</dict>
<dict>
<key>name</key>
<string>Item D</string>
<key>single</key>
<string>triple</string>
<key>colour</key>
<string>CF009E</string>
</dict>
<dict>
<key>name</key>
<string>Item E</string>
<key>style</key>
<string>single</string>
<key>colour</key>
<string>003CA6</string>
</dict>
<dict>
<key>name</key>
<string>Item F</string>
<key>style</key>
<string>double</string>
<key>colour</key>
<string>704B1C</string>
</dict>
<dict>
<key>name</key>
<string>Item G</string>
<key>style</key>
<string>double</string>
<key>colour</key>
<string>6EC4E8</string>
</dict>
<dict>
<key>name</key>
<string>Item H</string>
<key>style</key>
<string>single</string>
<key>colour</key>
<string>95BF32</string>
</dict>
</array>
</plist>
Extensions.swift
import Foundation
import UIKit
extension UIColor {
static let colorRed = UIColor().colorFromHex("A90F32")
static let colorTeal = UIColor().colorFromHex("427B7B")
static let colorGold = UIColor().colorFromHex("C9910D")
static let colorMagenta = UIColor().colorFromHex("CF009E")
static let colorNavy = UIColor().colorFromHex("003CA6")
static let colorBrown = UIColor().colorFromHex("704B1C")
static let colorLightBlue = UIColor().colorFromHex("6EC4E8")
static let colorGreen = UIColor().colorFromHex("95BF32")
func colorFromHex(_ hex : String) -> UIColor {
var hexString = hex.trimmingCharacters(in: .whitespacesAndNewlines).uppercased()
if hexString.hasPrefix("#") {
hexString.remove(at: hexString.startIndex)
}
if hexString.count != 6 {
return UIColor.black
}
var rgb : UInt32 = 0
Scanner(string: hexString).scanHexInt32(&rgb)
return UIColor.init(red: CGFloat((rgb & 0xFF0000) >> 16) / 255.0,
green: CGFloat((rgb & 0x00FF00) >> 8) / 255.0,
blue: CGFloat(rgb & 0x0000FF) / 255.0,
alpha: 1.0)
}
}
Items.swift (包含结构)
import Foundation
struct mainItem {
var title: String
var style: String
var color: String
}
var itemA = mainItem(title: "Item A", style: "single", color: "A90F32")
var itemB = mainItem(title: "Item B", style: "single", color: "427B7B")
var itemC = mainItem(title: "Item C", style: "single", color: "C9910D")
var itemD = mainItem(title: "Item D", style: "triple", color: "CF009E")
var itemE = mainItem(title: "Item E", style: "single", color: "003CA6")
var itemF = mainItem(title: "Item F", style: "double", color: "704B1C")
var itemG = mainItem(title: "Item G", style: "double", color: "6EC4E8")
var itemH = mainItem(title: "Item H", style: "single", color: "95BF32")
当前结果
预期结果
rmaddy的建议
发布于 2018-05-06 01:48:50
这里面有很多东西,所以把它分解一下吧。
首先,您需要一种创建垂直条的方法。您可以使用图像,但我建议您创建一个定义两个属性的自定义UIView
:样式(实线、两条线、三条线)和颜色。定义样式的enum
。实现draw
根据需要绘制彩色条形图。
一旦该自定义视图正常工作,就可以实现CustomCell
,以便在其contentView
的左端添加该自定义视图的一个实例。将条形样式和颜色的属性添加到CustomCell
类。设置这些属性应该会更新自定义条视图上的相应属性。
更新表视图控制器中的数据模型,以包括每行的颜色和样式。
更新cellForRowAt
以设置CustomCell
的标题、条形图样式和条形图颜色。
下面是实现条形图的一种方法:
class VerticalBarView: UIView {
enum Style {
case single
case double
case triple
}
var style: Style = .single {
didSet {
setNeedsDisplay()
}
}
var color = UIColor.black {
didSet {
setNeedsDisplay()
}
}
override func draw(_ rect: CGRect) {
(backgroundColor ?? .white).set()
let bg = UIBezierPath(rect: bounds)
bg.fill()
color.set()
switch style {
case .single:
let path = UIBezierPath(rect: bounds)
path.fill()
case .double:
let left = CGRect(x: 0, y: 0, width: bounds.width / 2 - 2, height: bounds.height)
var right = left
right.origin.x = right.width + 4
let pathLeft = UIBezierPath(rect: left)
pathLeft.fill()
let pathRight = UIBezierPath(rect: right)
pathRight.fill()
case .triple:
let width = (bounds.width - 8) / 3
var left: CGFloat = 0
for _ in 0..<3 {
let rect = CGRect(x: left, y: 0, width: width, height: bounds.height)
let path = UIBezierPath(rect: rect)
path.fill()
left += width + 4
}
}
}
}
// Test code
let view = VerticalBarView(frame: CGRect(x: 0, y: 0, width: 20, height: 44))
view.style = .triple
view.color = UIColor.purple
下面是CustomCell
的粗略实现
class CustomCell: UITableViewCell {
enum BarStyle {
case single
case double
case triple
}
var barStyle: BarStyle = .single {
didSet {
switch barStyle {
case .single:
bar.style = .single
case .double:
bar.style = .double
case .triple:
bar.style = .triple
}
}
}
var barColor = UIColor.black {
didSet {
bar.color = barColor
}
}
private let bar = VerticalBarView(frame: .zero)
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
commonInit()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
commonInit()
}
func commonInit() {
self.contentView.addSubview(bar)
let constraints = [
bar.topAnchor.constraint(equalTo: self.contentView.topAnchor),
bar.bottomAnchor.constraint(equalTo: self.contentView.bottomAnchor),
bar.leftAnchor.constraint(equalTo: self.contentView.leftAnchor),
bar.widthAnchor.constraint(equalToConstant: 20)
]
NSLayoutConstraint.activate(constraints)
}
}
您的cellForRowAt
如下所示:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! CustomCell
cell.textLabel?.text = allItems[indexPath.row].title
cell.barStyle = allItems[indexPath.row].style
cell.barColor = allItems[indexPath.row].color
return cell
}
这最后一段代码假设您已经将数据模型更新为一个结构数组,其中结构包含标题、样式和颜色。
https://stackoverflow.com/questions/50192321
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