用實現面向物件方法實現京東的五星好評效果。

滑鼠滑過時的顯示：

當評價完成後，關閉瀏覽器重新開啟頁面，還是上次的評價結果。用cookie實現。

具體實現如下：

import Componenet from "./Component.js";
 
export default class Stars extends Componenet {
 
    label;
    STARS_NUM = 5;
    starArr = [];
    score = 0;
    starsCon;
    faceIcon;
    scoreCon;
    index = -1;
    name;
    
    static STARS_LIST={};   //儲存當前頁面中所有的五星評價結果，一個商品為一組。用商品的id作為key，用商品評價組成一個數組，作為value。
    date=new Date();
 
    constructor(_label,_name) {
        super("div");
        this.name=_name;
        this.label = _label;
        Object.assign(this.elem.style,{
            width:"200px",height: "16px",float: "left",marginRight: "20px",marginBottom: "10px",fontSize: "12px",color: "#666",lineHeight: "16px",userSelect: "none",position: "relative",top: "20px",left: "20px",})
        // 解析cookie中儲存的評論結果並在建立每個評論時初始化score的值。
        this.initScore();
        // 建立評價標籤部分
        this.createLabel();
        // 建立星星部分
        this.createStars();
        // 建立分數部分
        this.createScore();
        // 初始化星星樣式。
        this.changeStarStyle(this.score-1);
        // 初始化分數
        this.changeScore(this.score);
        // 新增滑鼠滑過點選事件。
        this.starsCon.addEventListener("mouseenter",e => this.mouseHandler(e));
        this.starsCon.addEventListener("mouseleave",e => this.mouseHandler(e));
        this.starsCon.addEventListener("mouseover",e => this.mouseHandler(e));
        this.starsCon.addEventListener("click",e => this.clickHandler(e));
        this.date.setFullYear(2021);
    }
    appendTo(_parent){
        super.appendTo(_parent);
        if(!Stars.STARS_LIST[this.name]) Stars.STARS_LI
 
ST[this.name]=[];
        Stars.STARS_LIST[this.name].push(this.label+"="+this.score);
    }
    clickHandler(e){
        if(e.target.constructor!==HTMLLIElement) return
        this.index = this.starArr.indexOf(e.target);
        this.score = this.index+1;
        this.changeStarStyle(this.index);
        this.changeScore(this.index+1);
        // 每次點選都將評論的結果儲存到cookie中，以便下次開啟頁面時讀取。STARS_LIST中儲存的是label作為key，score作為value的資料。
        this.storageScore();
    }
    storageScore(){
        for(let prop in Stars.STARS_LIST){
            if(prop === this.name){
                Stars.STARS_LIST[prop]www.cppcns.com
 
.forEach((item,index)=>{
                    if(item.includes(this.label)) Stars.STARS_LIST[prop][index] = this.label+"="+this.score;
                });
            }
        }
        document.cookie="comment="+ JSON.stringify(Stars.STARS_LIST)+";expires="+this.date.toUTCString();
    }
    mouseHandler(e) {
        switch (e.type) {
            case "mouseenter":
                this.faceIcon.style.display = "block";
                break;
            case "mouseleave":
                this.faceIcon.style.display = "none";
                this.changeStarStyle(this.index);
                this.changeScore(this.score);
                break;
            case "mouseover":
                let index = this.starArr.indexOf(e.target);
                this.changeStarStyle(index);
                this.changeScore(index + 1);
                this.changeFaceStyle(index);
                break;
        }
    }
    changeStarStyle(_i) {
        for (let n = 0; n < this.starArr.length; n++) {
   
 
         if (n <= _i || n < this.score) {
                this.starArr[n].style.backgroundPositionY = "-16px";
            } else {
                this.starArr[n].style.backgroundPositionY = "0px";
            }
        }
    }
    changeFaceStyle(_i) {
        this.faceIcon.style.left = _i * 16 + "px";
        this.faceIcon.style.backgroundPositionX = (_i + 1) * 20 + "px";
    }
    changeScore(_i) {
        this.scoreCon.textContent = _i + "分";
    }
    createLabel() {
        let label = document.createElement("span");
        Object.assign(label.style,{
            float: "left",padding: "0 5px",})
        label.textContent = this.label;
        this.elem.appendChild(label);
    }
    createStars() {
        this.starsCon = document.createElement("ul");
        Object.assign(this.starsCon.style,{
            margin: 0,padding: 0,listStyle: "none",width: "80px",})
        for (let i = 0; i < this.STARS_NUM; i++) {
            let li = document.createElement("li");
            Object.assign(li.style,{
                width: "16px",backgroundImage: "url(./star_img/commstar.png)",})
            this.starArr.push(li);
            this.starsCon.appendChild(li);
        }
        this.faceIcon = document.createElement("div");
        Object.assign(this.faceIcon.style,{
            width: "16px",backgroundImage: "url(./star_img/face-red.png)",backgroundPositionX: "-80px",position: "abylENQkmsolute",left: "0",top: "-16px",display: "none",})
        this.starsCon.appendChild(this.faceIcon);
        this.elem.appendChild(this.starsCon);
    }
    createScore() {
        this.scoreCon = document.createElement("div");
        Object.assign(this.scoreCon.style,{
            height: "16px",width:"20px",})
        this.scoreCon.textContent = this.score + "分",this.elem.appendChild(this.scoreCon);
    }
    initScore(){
        // 直接讀取cookie顯示如下
        // comment={"1001":["商品符合度=5","店家服務態度=0","快遞配送速度=0","快遞員服務=0","快遞包裝=0"],"1002":["商品符合度=0","快遞包裝=0"]}
 
        // 解析cookie中儲存的評論結果。
        if(!document.cookie.includes("comment=")) return
        let o = JSON.parse(document.cookie.match(/(\{.*?\})/)[1]);
        if(!o) return
        // 解析後的o如下
        // ["商品符合度=1","快遞包裝=0"]
        for(let prop in o){
            if(this.name===prop){
                this.score=o[prop].reduce((value,item,index)=>{
                    let arr=item.split("=");
                    if(arr[0].includes(this.label)) value=parseInt(arr[1]);
                    return value;
                },0)
            }
        }
    }
}

使用時傳入標籤，新建例項。

import Stars from './js/Stars.js';
let list=["商品符合度","店家服務態度","快遞配送速度","快遞員服務","快遞包裝"];
 
        // let star = new Stars(list[0]);
        // star.appendTo("body");
 
        list.forEach(item=>{
            // 傳入標籤和對應的商品id
            let star = new Stars(item,"1001");
            star.appendTo(".div1");
        })
        list.forEach(item=>{
            let star = new Stars(item,"1002");
            star.appendTo(".div2");
        })

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支援我們。