自定义分段选择器
1.ViewController
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
//系统的分段选择器
let segement = UISegmentedControl.init(items: ["1","2","3"])
segement.frame = CGRectMake(100, 100, 200, 50)
self.view.addSubview(segement)
segement.selectedSegmentIndex = 1
segement.addTarget(self, action: "action", forControlEvents: .ValueChanged)
//自己的分段选择器
let selfSegement = YTSegmentControl.init(items: ["海贼","路飞"])
selfSegement.frame = CGRectMake(100, 200, 200, 50)
selfSegement.titleColor = UIColor.redColor()
selfSegement.titleSelectedColor = UIColor.greenColor()
selfSegement.selectedSegmentIndex = 1
selfSegement.addTarget(self, action: "selfAction:")
self.view.addSubview(selfSegement)
}
func selfAction(segement:YTSegmentControl) {
print("自己的选择器在做切换")
print(segement.selectedSegmentIndex)
}
func action() {
print("系统的选择器在做切换")
}
}
2. YTSegmentControl
import UIKit
let BtnTag = 100
class YTSegmentControl: UIView {
//MARK: - 属性
///1.当前被选中的按钮的下标
var selectedSegmentIndex = 0{
//将要将新值赋给selectedSegmentIndex。这个selectedSegmentIndex还是原来
willSet{
//1.先将原来选中的按钮变成非选中状态
let btn1 = self.viewWithTag(BtnTag
+ selectedSegmentIndex) as! UIButton
btn1.selected = false
//2.将指定的按钮变成选中状态
//newValue -> 将要赋给当前属性的那个新的值
let btn2 = self.viewWithTag(BtnTag + newValue) as! UIButton
btn2.selected = true
}
//已经给selectedSegmentIndex赋值
didSet{
UIView.animateWithDuration(0.2) {
self.slider.frame.origin.x = CGFloat(self.selectedSegmentIndex) * self.slider.frame.size.width
}
}
}
///2.文字选中的颜色
var titleSelectedColor = UIColor.blueColor(){
didSet{
//更新滑块的背景颜色
self.slider.backgroundColor = self.titleSelectedColor
for item in self.subviews {
if item.tag >= BtnTag {
let btn = item as! UIButton
//改变按钮的文字颜色
btn.setTitleColor(self.titleSelectedColor, forState: .Selected)
}
}
}
}
///3.文字颜色
var titleColor = UIColor.blackColor(){
//每次从外部给titleColor属性赋值的时候，都需要用最新的titleColor的值去更新按钮的文字颜色
didSet{
for item in self.subviews {
if item.tag >= BtnTag {
let btn = item as! UIButton
//改变按钮的文字颜色
btn.setTitleColor(self.titleColor, forState: .Normal)
}
}
}
}
///4.items
private var items:[String]
///5.滑块
private var slider = UIView()
///6.保存target
private var target: AnyObject? = nil
///7.保存action
private var action: Selector? = nil
//MARK: - 构造方法
init(items:[String]){
self.items = items
//CGRectZero ->坐标是(0,0),大小是(0,0)
super.init(frame: CGRectZero)
//创建items中的每个数组元素对应的按钮
self.creatSubView()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
//MARK: - 提供给外部使用的方法
extension YTSegmentControl{
//保存target和action值
func addTarget(target:AnyObject?, action:Selector) {
self.target = target
self.action = action
}
}
//MARK: - 创建子视图
extension YTSegmentControl{
func creatSubView() {
//1.创建按钮
for (i,item) in self.items.enumerate() {
//创建按钮不设置frame属性
let btn = UIButton.init()
//设置文字
btn.setTitle(item, forState: .Normal)
//设置tag值
btn.tag = BtnTag + i
//设置文字颜色
btn.setTitleColor(self.titleColor, forState: .Normal)
btn.setTitleColor(self.titleSelectedColor, forState: .Selected)
//让默认第0个按钮处于选中状态
if i == 0 {
btn.selected = true
}
//添加点击事件
btn.addTarget(self, action: "btnAction:", forControlEvents: .TouchDown)
//添加到界面上
self.addSubview(btn)
}
//2.创建滑块
self.slider.backgroundColor = self.titleSelectedColor
self.addSubview(self.slider)
}
}
//MARK: - 按钮点击事件
extension YTSegmentControl{
func btnAction(btn:UIButton) {
if self.selectedSegmentIndex != btn.tag - BtnTag {
//更新选中的下标
self.selectedSegmentIndex = btn.tag - BtnTag
//通知外部值改变了
if self.target != nil {
//让target去调用action中的方法
//参数1:需要调用的方法对应的Selecter
//参数2:如果Selecter中方法带参，那个这个参数的值就是Selecter中方法的实参
self.target?.performSelector(self.action!, withObject:self)
}
}
}
}
//MARK: - 计算子视图的frame
extension YTSegmentControl{
override func layoutSubviews() {
super.layoutSubviews()
//当前分段选择器的宽和高
let segementW = self.frame.size.width
let segementH = self.frame.size.height
//1.计算按钮的frame
let btnW = segementW/CGFloat(self.items.count)
let btnH = segementH
let btnY: CGFloat = 0
//遍历所有的子视图
var i: CGFloat = 0
for item in self.subviews {
//找到其中的按钮
if item.tag >= BtnTag {
let btnX = i * btnW
item.frame = CGRectMake(btnX, btnY, btnW, btnH)
//找到一个按钮i加1
i += 1
}
}
//2.计算滑块的frame
let sliderX = CGFloat(self.selectedSegmentIndex) * btnW
let sliderH: CGFloat = 2
let sliderY = segementH - sliderH
let sliderW = btnW
self.slider.frame = CGRectMake(sliderX, sliderY, sliderW, sliderH)
}
}
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