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Events in BOM, DOM and JS

大家讲道理
大家讲道理Original
2018-05-17 15:58:243265browse

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>然后是setInterval与clearInterval</title>
        <!--要记得首先打开控制台哟~-->
        <script type="text/javascript">            var num = 10;            var timeinterval = setInterval(function(){
                num--;
                console.log(num);                if (num==0){
                clearInterval(timeinterval);
                }
            },1000)            function clearIntervalBtn(){
                clearInterval(timeinterval);
            }        </script>
    </head>
    <body>
        <button onclick="clearIntervalBtn()">clearIntervar</button>
    </body>
</html>

2.2 BOM’s side rooms—a brief description of other objects.

Because BOM objects other than window objects rarely appear in actual JS writing, this K will briefly mention them in the form of code.

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>BOM的侧室们</title>
        <!--要记得首先打开控制台哟~-->
        
        <script type="text/javascript">            
            // screen对象            
            console.log(screen);
            console.log(screen.width);//宽度            console.log(screen.height);//高度            console.log(screen.availHeight);//可用高度=屏幕高度-底部任务栏            console.log(screen.availWidth);//可用宽度
            
            // location对象
            //   完整的url路径: 
            //   协议:// 主机名(IP地址):端口号(默认80端口)/文件路径?传递的参数(参数名0=参数值0&参数名1=参数值1)#锚点            
            console.log(location);
            console.log(location.href);//完整路径            console.log(location.protocol);//路径协议http: https: ftp: file: mailto:             console.log(location.pathname);//路径部分  /开始            console.log(location.port);//端口号            console.log(location.search);//从?开始往后的部分            console.log(location.hostname);//IP地址            console.log(location.host);//主机名+端口号            console.log(location.hash);//从#开始的锚点
            // 使用JS设置页面跳转
            //    window.location="http://www.baidu.com";
            
            function locationReload(){                //重新加载当前页面                location.reload(true);//reload(true)表示从服务器重新加载当前页面;reload()在本地刷新当前页面            }            
            function locationAssign(){
                location.assign("http://www.baidu.com");    //加载新的文档,替换以后可以回退            }            
            function locationReplace(){
                location.replace("http://www.baidu.com");//使用新的文档替换当前文档,替换后不能回退            }            
            // history
            // length : 浏览历史列表的个数
            // history.forward(); : 前进到前一个页面
            // history.back(); : 后退到后一个页面
            // history.go(); : 跳转到历史浏览历史的任意位置;当前页为第0个,前一个页面为第1个,后一个页面为第-1个            
            console.log(history.length);            
            function historyForword(){
                history.forward();
            }            function historyBack(){
                history.back();
            }            function historyGo(){
                history.go();                // 0 
                // 1 = history.forward();
                // -1 = history.back();            }            
            // Navigator            console.log(navigator.appName);//产品名称            console.log(navigator.appVersion);//产品版本号            console.log(navigator.userAgent);//用户代理信息            console.log(navigator.platform);//系统代理平台            
            console.log(navigator.plugins);//检查浏览器安装的插件信息
            // 返回一个数组,检测浏览器安装的所有插件(↓主要属性↓)
            // description : 插件描述信息
            // filename : 插件在本地磁盘的文件名
            // length : 插件的个数
            // name : 文件名        
            console.log(navigator.mimeTypes);//浏览器插件所支持的文件类型(↓主要属性↓)
            // description:MIME类型描述
            // enabledPlugin:支持此类型的浏览器插件
            // suffixes:此类型可能的后缀名
            // type:MIME类型的写法,例如:image/x-icon text/css
        </script>
        
    </head>
    <body>
        
        <button onclick="locationAssign()">加载新的文档</button>
        <br />
        
        <button onclick="locationReload()">重新加载当前文档</button>
        <br />
        
        <button onclick="locationReplace()">使用新的文档替换当前文档</button>
        <br />
        
        <button onclick="historyForword()">这个是historyForword</button>
        <br />
        
        <button onclick="historyBack()">这个是historyBack</button>
        <br />
        
        <button onclick="historyGo()">这个是historyGo</button>
        
    </body>
</html>

二、“N世同堂”——DOM

1、朝阳群众又立功,代码中竟出现如此神秘的“庞大组织”——DOM简介

    DOM(Document Object Model),是指文档对象模型,是W3C组织推荐的处理可扩展标志语言的标准编程接口。在网页上,组织页面(或文档)的对象被组织在一个树形结构中,用来表示文档中对象的标准模型,而DOM中的每一条分支都被称作一个“节点”,所有节点及节点属性构成的结构图会呈现出很强的层次性(栗子如下图,源于万能的度娘)。

    DOM节点分为三大类:元素节点,文本节点,属性节点。文本节点、属性节点为元素节点的两个子节点,通过gelElement系列方法,可以取到元素节点。

2、如此组织,其真相竟然是...——DOM操作详解

    DOM操作是JS中应用性非常强的一部分,所以本K就以代码的形式来给大家叙述。

2.1 获取节点与样式修改

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>DOM代码详述(一)</title>
        
        <script type="text/javascript">            

            
            window.onload = function(){                var p1 = document.getElementById("p1");//通过ID获取唯一的节点;多个同名ID只会取第一个                console.log(p1);
                
                console.log(p1.tagName);//查看节点:①属性;获取节点的标签名                console.log(p1.innerHTML);//②设置或者获取节点内部的所有HTML代码                console.log(p1.innerText);//③设置或者获取节点内部的所有文字                
                console.log(window.getComputedStyle(p1,null));//查看所有属性(非IE属性)                console.log(p1.currentStyle);//查看所有属性(IE属性)                
            }            function getById(){                //取到元素节点的样式属性节点
                var p1 = document.getElementById("p1").style;//获取                p1.backgroundColor = "#FF00FF";//行级样式表权重1000;所有节点属性,一律驼峰命名法
                
                //取到元素节点
                var pDoc = document.getElementById("p1");//获取                pDoc.innerHTML = "<s>king_land</s>";//重置修改p中的HTML代码            }            
            //——————————————分割线——————————————————
            
            function getByName(){//通过Name取到一个数组,包含1到多个节点;
                
                var p = document.getElementsByName("p1");
                
                console.log(p.length);                
                //使用方式:通过循环,取到每一个节点,循环次数从0开始,<数组.length
                for(var n = 0 ;n < p.length ; n++){
                    p[n].style.backgroundColor = "#FFFF00";
                }                
                //p1.backgroundColor = "#FFFF00";
                //p[0].style.backgroundColor = "#FFFF00";//★                
            }            
            //——————————————分割线——————————————————
            
            //document.getElementsByTagName();//同Name

            function getByTagName(){                
                var p = document.getElementsByTagName("p");
                
                p[0].style.backgroundColor = "#00FF00";
                
            }            
            //——————————————分割线——————————————————
            
            //document.getElementsByClassName();//同Name

            function getByClass(){                
                var p = document.getElementsByClassName("p1");
                
                p[0].style.backgroundColor = "#00FFFF";
                
            }            //——————————————分割线——————————————————
            
            function getAttr () {                
                var img1 = document.getElementById("img1");
                alert(img1.getAttribute("src"));
                
            }//查看属性节点 getAttribute("属性名");
            
            //——————————————分割线——————————————————
            
            function setAttr () {                
                var img1 = document.getElementById("img1");
                img1.setAttribute("src","../../2-CSS基础语法/img/bg_flower_multi.gif");
                img1.setAttribute("style","width: 100px;height: 100px;");
                
            }//设置属性节点 getAttribute("属性名","属性值");
            
            //——————————————分割线——————————————————
            
            //JS修改样式总结
            //1、.className:为元素设置一个新的class名字   例如:p1.className = "p2";
            //2、.style:为元素设置新的样式   例如:p1.style.background-color = "blue";
            //3、.style.cssText:为元素同时修改多个样式   例如:p1.style.cssText = "width:100px;height:200px;";
            

            
            
            
        </script>
        
        <style type="text/css">
            
            .p1{
                height: 100px;
                width: 100px;
                background-color: #000000;
                color: #FFFFFF;
                line-height: 100px;
                text-align: center;
            }
            
        </style>
        
        
    </head>
    <body>
        
        <p id="p1" name="p1" class="p1">
            这里是测试区
        </p>
        <p id="p1" name="p1" class="p1">
            这里是测试区
        </p>
        <p id="p1" name="p1" class="p1">
            这里是测试区
        </p>
        <img src="../../2-CSS基础语法/img/bg_flower_multi.gif" id="img1"/>
        
        
        <br />
        <button onclick="getById()">通过ID修改pcolor</button>
        <br />
        <button onclick="getByName()">通过Name修改pcolor</button>
        <br />
        <button onclick="getByTagName()">通过TagName修改pcolor</button>
        <br />
        <button onclick="getByClass()">通过ClassName修改pcolor</button>
        <br />
        <button onclick="getAttr()">取到img的src属性值</button>
        <br />
        <button onclick="setAttr()">修改img的src属性值</button>
        
    </body>
</html>

2.2 层次节点常用操作

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
        
        <script type="text/javascript">
            
                window.onload = function (){                    
                    //获取层次节点的常用属性
                    
                    var ul1 = document.getElementById("ul1");                    
//                    var lis = ul1.getElementsByTagName("li");  //只取到ul1中所有li//                    var lis = document.getElementsByTagName("li");  //取到页面中所有的li
                    console.log(ul1.childNodes);//获取元素的所有子节点(包含元素节点、文本节点)                    
                    console.log(ul1.firstChild);//获取元素的第一个子节点                    
                    console.log(ul1.lastChild);//获取元素的最后一个子节点                    
                    console.log(ul1.ownerDocument);//获取当前文档根节点,在html文档中为document节点                    
                    console.log(ul1.parentNode);//获取当前节点的父节点                    
                    console.log(ul1.previousSibling);//获取当前节点的前一个兄弟节点                    
                    console.log(ul1.nextSibling);//获取当前节点的后一个兄弟节点
                    
                    //上述属性均会获得所有的元素节点和文本节点,如果只需要元素节点,需要使用对应Element属性,例如:firstChild→firstElementChild                    
                    console.log(ul1.attributes);//获取当前节点的所有属性节点                    
                }                
                //——————————————创建并新增节点——————————————————
                    
                //方法一:.creatElement("标签名")创建一个新节点,需要配合setAttribute()方法设置属性;
                //方法二:.appendChild(节点名)在元素的最后追加一个新节点
                //方法三:.insertBefore(新节点名,目标节点名):将新节点插入到目标节点之前
                //方法四:克隆对象.cloneNode(true/false):需要克隆谁,就用谁去调用克隆节点;传递参数可以为true/false,true表示克隆当前节点及子节点;false表示只克隆当前节点,不克隆子节点。
                    
                function appendImg(){                    
                    //1、创建一个图片节点
                    var img = document.createElement("img");                    //2、给img节点设置属性                    img.setAttribute("src","../../1-HTML基本标签/ivicon.png");                    //3、将设置好的img节点追加到body最后                    document.body.appendChild(img)//.setAttribute("src","../../img/2017-02-25_143342.png");                    
                }                
                function insertImg(){                    
                    //1、创建一个图片节点
                    var img = document.createElement("img");                    //2、给img节点设置属性                    img.setAttribute("src","../../1-HTML基本标签/ivicon.png");                    //3、在两个ul之间插入图片
                    var ul2 = document.getElementById("ul2");
                    document.body.insertBefore(img,ul2);
                    
                }                var count = 2;                function copyUl(){                    
                    //1、取到ul2节点
                    var ul2 = document.getElementById("ul2");                    //2、克隆节点
                    var ul2Clon = ul2.cloneNode(true);
                    count ++;
                    ul2Clon.setAttribute("id","ul"+count)                    //3、在原ul2节点之前,插入新克隆节点                    document.body.insertBefore(ul2Clon,ul2);
                    
                }                
                //——————————————删除和替换节点——————————————————
                
                //1、.removeChild(需删除节点):从父容器中删除指定节点;
                //2、.replaceChild(新节点,被替换节点):用新节点替换被指定节点,如果新节点为页面中已有节点,会将此节点删除后替换到指定节点。
                
                function deleteUl1(){                    
                    //取到ul1
                    var ul1 = document.getElementById("ul1");                    if (ul1){                        //从父容器body中删除ul1节点                        document.body.removeChild(ul1);
                    }else{
                        alert("憋删了,早没了");
                    }
                    
                }                
                function ul1ReplaceUl2(){                    
                    var p = document.createElement("p");
                    p.setAttribute("style","width: 100px;height: 100px;background-color: #20B2AA;");                    var ul2 = document.getElementById("ul2");
                    document.body.replaceChild(p,ul2);
                    
                }                
        </script>
        
        <style type="text/css">
            
            ul{
                width: 600px;
                list-style: none;
                padding: 0;
                background-color: #20B2AA;
                display: flex;
                justify-content: space-around;
                margin-top: 20px;
            }
        
        </style>
        
    </head>
    <body>
        
        <ul id="ul1">
            <li>第一项</li>
            <li>第二项</li>
            <li>第三项</li>
            <li>第四项</li>
        </ul>
        
        <ul id="ul2">
            <li>第1项</li>
            <li>第2项</li>
            <li>第3项</li>
            <li>第4项</li>
        </ul>
        
        <button onclick="appendImg()">在最后插入一幅图片</button>
        <button onclick="insertImg()">在两个ul之间插入一幅图片</button>
        <button onclick="copyUl()">copy一个ul2</button>
        <br />
        
        <button onclick="deleteUl1()">删除ul1</button>
        <button onclick="ul1ReplaceUl2() ">用ul1替换ul2</button>
        
        
        
        
    </body>
</html>

2.3 表格操作

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>DOM操作表格</title>
        
        <script type="text/javascript">            
            //表格对象:
            //1、rows属性:返回表格中的所有行,数组;
            //2、insertRow(index):在表格的第index+1行,插入一个新行;
            //3、deleteRow(index):删除表格的第index+1行;
            
            //表格的行对象:
            //1、cells属性:返回当前行中的所有单元格,数组;
            //2、rowIndex属性:返回当前行在表格中的索引顺序,从0开始;
            //3、insertCell(index):在当前行的index+1处插入一个td;
            //4、deleteCell(index):删除当前行的第index+1个td;
            
            //表格的单元格对象:
            //1、cellIndex属性:返回单元格在该行的索引顺序,从0开始;
            //2、innerHTML属性:设置或者返回当前单元格中的HTMl代码;
            //3、align(valign)属性:设置当前单元格的水平对齐方式;
            //4、className属性:设置单元格的class名称。
            
            function newRow(){                
                var book = prompt("书名:");                var price = prompt("价格:");                
                var table = document.getElementsByTagName("table");                //在表格的最后一行插入一个新行
                var newRow = table[0].insertRow(table[0].rows.length-1);                //给新行设置单元格
                var cell0 = newRow.insertCell(0);
                cell0.innerHTML = book;                var cell1 = newRow.insertCell(1);
                cell1.innerHTML = price;
                
                getSum();
                
            }            
            function deleteRow(){                
                var table = document.getElementsByTagName("table");                if(table[0].rows.length>2){
                    table[0].deleteRow(table[0].rows.length-2);
                }else{
                    alert("删删删!删你妹啊删!")
                }
                getSum();
            }            
            function changeTitle(){                
                var color = prompt("请输入6位十六进制颜色值:");                var table = document.getElementsByTagName("table");
                table[0].rows[0].style = "background-color:#"+color;
                
            }            
            function copyRow(){                
                var table = document.getElementsByTagName("table");                var copyRow = table[0].rows[table[0].rows.length-2].cloneNode(true);                var heJi = table[0].rows[table[0].rows.length-1];                //由于浏览器,自动将表格的<tr>包裹在<tbody>中
                //所以<tr>实际并非<table>的子节点,故需取到<table>中的<tbody>进行插入;
                
                if(table[0].rows.length>2){
                    table[0].getElementsByTagName("tbody")[0].insertBefore(copyRow,heJi);
                }else{
                    alert("没有可以复制的行");
                }
                getSum();
            }            
            function getSum(){                //取到当前表格 表格所有行
                var table = document.getElementsByTagName("table");                var rows = table[0].rows;                //                if(rows.length<=2){
                    rows[rows.length-1].cells[1].innerText = 0 + "元";
                    alert("没有可计算的行!");                    return;
                }                //求和
                var sum = 0 ;                
                for(var i = 1 ; i <= rows.length-2 ; i++){//第0行与最后一行舍弃1  rows.length-2
                    
                    var cells = rows[i].cells;//取到单元格                    sum += parseFloat(cells[cells.length-1].innerText);//最后一个单元格的  内容(innerText) 转化成数字并求和计算!                    
                }
                
                rows[rows.length-1].cells[cells.length-1].innerText = sum.toFixed(2) + "元";
                
            }
            
            window.onload = function(){
                getSum();
            }            
            
        </script>
        
        <style type="text/css">
            
            table{
                border-collapse: collapse;
                width: 400px;
                text-align: center;
                color: #585858;
            }
            td,th{
                border: 1px solid #8B8A8B;
            }
            table tr:last-child{
                color: #E70014;
            }
            
        </style>
        
    </head>
    <body>
        
        
        <table>
            <tr>
                <th>书名</th>
                <th>价格</th>
            </tr>
            <tr>
                <td>看得见风景的房间</td>
                <td>30.00元</td>
            </tr>
            <tr>
                <td>幸福从天而降</td>
                <td>18.50元</td>
            </tr>
            <tr>
                <td>60个瞬间</td>
                <td>32.00元</td>
            </tr>
            <tr>
                <td>合计</td>
                <td></td>
            </tr>
        </table>
        
        <br />
        
        <button onclick="newRow()">增加一行</button>
        <button onclick="deleteRow()">删除最后一行</button>
        <button onclick="changeTitle()">修改标题样式</button>
        <button onclick="copyRow()">复制最后一行</button>
        

    </body>
</html>

三、鼠标和键盘、那些不得不说的事——JS中的事件

1、三足鼎立——JS中的事件分类

1.1 鼠标事件

click 单击

dblclick 双击

mouseover 鼠标移入

mouseout 鼠标移出

mousemove 鼠标划过

mousedown 鼠标按下

mouseup 鼠标抬起

1.2 键盘事件

keydown:键盘按下时触发

keypress:键盘按下并松开的瞬间触发

keyup:键盘抬起时触发

Notes
①Execution sequence: keydown keypress keyup
②When long pressed, it will be executed continuously in a loop keydown keypress
③There is a keydown event, but there may not be a keyup event (during the event triggering process, if the mouse is moved, there may be no keyup)
④The keypress event can only be captured Letters, numbers, and symbols (including carriage returns and spaces) cannot capture function keys; keydown keyup can basically capture all function keys, with special exceptions
⑤keypress is case-sensitive, keydown keyup is not;
⑥keypress does not distinguish between the main keyboard and the small keyboard, but keydown keyup does;
[How to determine the keyboard trigger key]
⑴ In the trigger function , the trigger parameter e represents the key event;
⑵ Confirm the case Ascii code value through e.keyCode, and then determine the key;
⑶ Compatible with all browsers (generally unnecessary):
var evn = e||event; //Get the button
var code = evn .keyCode||evn.which||evn.charCode; //Get the key code

1.3 HTML event

2. This shore and the other shore - event model in JS

2.1 DOM0 event model

2.1. 1 Inline model: directly use the function name as the attribute value of an event attribute of the HTML tag; ;/button>
Disadvantages: Violates W3C’s basic principle
on the separation of HTML and JS! 2.1.2 Script model: Binding through event attributes in JS script;


# Limitations: The same node can only be bound to one event of the same type;
2.2 DOM2 event model (there will be chestnuts later!)

Advantages: Multiple listeners for events of the same type can be added to the same node;

①添加事件绑定:
IE10之前:btn1.attachEvent("onclick",函数);
其他浏览器:btn1.addEventListener("click",函数,true/false);
true:表示事件捕获;false(默认):表示事件冒泡
兼容写法:if(btn1.attackEvent){btn1.attachEvent("onclick",函数);}else{btn1.addEventListener("click",函数,true/false);}
②取消事件绑定:
.detachEvent("onclick",函数名);
.removeEventListener("click",函数名);
注:如果取消时间帮顶,回调函数必须使用有名函数,而不能使用匿名函数。因为在取消事件帮顶时,需要传入函数名;

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>这里是栗子</title>
        
        <script type="text/javascript">
            window.onload = function (){                
                var btn1 = document.getElementById("btn1");                function func1(){
                    alert(1);
                }                function func2(){
                    alert(2);
                }
                btn1.addEventListener("click",func1,false);
                btn1.addEventListener("click",func2,false);                
                var btn2 = document.getElementById("btn2");
                btn2.addEventListener("click",function(){
                    btn1.removeEventListener("click",func1);
                },false);
                
            }        </script>
    </head>
    <body>
        
        <button id="btn1">点我会弹窗!</button>
        
        <br /><br />
        
        <button id="btn2">点我不弹窗!</button>
    </body>
</html>

3、上上下下——JS中的事件流

3.1 事件冒泡

当某DOM元素触发某事件时,会从当前DOM元素开始,逐个触发其祖先元素的同类型事件,直到DOM根节点;
DOM0事件流均为事件冒泡;
IE中使用.attachEvent()事件,均为冒泡;
其他浏览器.addEventListener()添加的事件,当第三个参数为false时,为冒泡。

3.2 事件捕获

当某DOM元素触发某事件时,会从DOM根节点,逐个触发其祖先元素的同类型事件,直到触发到当前DOM元素开始;

只有使用.addEventListener()添加的事件,并且当第三个参数为true时,才进行捕获。

3.3 阻止事件冒泡

IE浏览器:将e.cancelBubble属性设为true;
其他浏览器:调用e.stopPropagation();方法

3.4 取消事件默认行为

IE浏览器:将e.returnValue属性设为false;
其他浏览器:调用e.preventDefault(); 方法

(这里有栗子)

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>事件流举栗</title>
        <style type="text/css">
            
            #p1{
                width: 200px;
                height: 200px;
                background-color: #20B2AA;
                color: #FFFFFF;
                font-size: 20px;
                font-weight: 700;
            }
            #p2{
                width: 100px;
                height: 100px;
                background-color: #436690;
                color: #FFFFFF;
                font-size: 20px;
                font-weight: 700;
            }
            #p3{
                width: 50px;
                height: 50px;
                background-color: #4E2E83;
                color: #FFFFFF;
                font-size: 20px;
                font-weight: 700;
            }
            
        </style>
        
    </head>
    <body>
        <p id="p1">
            <p id="p2">
                <p id="p3">3</p>
                2
            </p>
            1
        </p>

        <a href="../07 JS中的DOM/笔记.html" onclick="stopHref()">跳转页面</a>
    </body>
    
    <script type="text/javascript">        var p1 = document.getElementById("p1");        var p2 = document.getElementById("p2");        var p3 = document.getElementById("p3");
        
        p1.addEventListener("click",function(e){
            handleE();
            console.log("p1触发了click事件");
        },false);
        
        p2.addEventListener("click",function(e){
            handleE();
            console.log("p2触发了click事件");
        },false);
        
        p3.addEventListener("click",function(e){
            handleE();
            console.log("p3触发了click事件");
        },false);        function handleE(e){            var evn = e||window.event;
            evn.stopPropagation();    
        }        function stopHref(e){
            
            e = e||window.event;            if (e.preventDefault) {
                e.preventDefault(); //IE以外             } else {
                e.returnValue = false; //IE                 }

            alert("好气呀!");
            
        }        
    </script>
    
</html>

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