h5 production performance change line chart-H5 Tutorial-php.cn

This time I will bring you a line chart of h5 production performance changes. What are the precautions for making h5 performance change line charts? The following is a practical case, let's take a look.

By dynamically setting the inner element height =>

    <!DOCTYPE html><html><head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>示例1</title>
    <style>
        #title {            margin: 2px;            font-family: Helvetica, Arial, sans-serif;            font-size: 9px;            font-weight: bold;            line-height: 15px;            color: rgb(0, 255, 255);
        }        #demo {            width: 74px;            height: 30px;            background: rgb(0, 255, 255);            margin: 2px
        }        span.col {            width: 1px;            height: 100%;            float: left;            opacity: 0.9;            background: rgb(0, 0, 34);
        }    </style></head><body>
    <div style=" opacity: 0.9; cursor: pointer; position: absolute; top: 0px;margin: 10px; background: rgb(0, 0, 34);">
        <div id="title"></div>
        <div id="demo"></div>
    </div>
    <script>
        function fillLineChart(id) {            this.id = id;            this.el = document.getElementById(id);            this.value = 0;//当前值
            this.width = parseInt(this.el.clientWidth)            this.last=this.width-1;//从左往右最后一个span的索引
            for (var i = 0; i < this.width; i++) {//初始化span
                this.el.innerHTML +=&#39;<span class="col"></span>&#39;;
            }            this.draw = function (value) {//绘制事件
                this.value = value;//记录当前值
                for (var i = 0; i <this.last; i++) {//遍历前x-1个,将后一个值赋给前一个
                    var tmph = this.el.getElementsByTagName("span")[i + 1].style.height;//获取下一个值
                    this.el.getElementsByTagName("span")[i].style.height = tmph;//赋给当前的
                }                this.el.getElementsByTagName("span")[this.last].style.height = parseInt(this.el.clientHeight) * (100 - this.value) / 100 + "px";//设置最后span一个高度=span容器的高度x值百分比
            }
        }        var demo = new fillLineChart("demo");        var val = 0
        setInterval(function () {
            val = rand(rand(20, 50), 60);            document.getElementById(&#39;title&#39;).innerHTML = `示例(${val})`
            demo.draw(val);
        }, 100);        function rand(begin, end) {            return Math.floor(Math.random() * (end - begin)) + begin;
        }    </script></body></html>

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2. Through Canvas =>[Example]

<!DOCTYPE html><html><head>
    <meta charset="UTF-8">
    <title>示例2</title>
    <style>
        #title {            margin: 2px;            font-family: Helvetica, Arial, sans-serif;            font-size: 9px;            font-weight: bold;            line-height: 15px;            color: rgb(0, 255, 255);
        }        #demo { 
            margin: 2px
        }        span.col {            width: 1px;            height: 100%;            float: left;            opacity: 0.9;            background: rgb(0, 0, 34);
        }    </style></head><body>
    <div style=" opacity: 0.9; cursor: pointer; position: absolute; top: 0px;margin: 10px; background: rgb(0, 0, 34);">
        <div id="title"></div>
        <canvas id="demo" width="74" height="30"></canvas>
    </div>
    <script>
        function fillLineChart(id) {            this.id = id;            this.canvas = document.getElementById(id);            this.value = 0;            this.width = (this.canvas.clientWidth)//获取

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Binding width

           this.height = (this.canvas.clientHeight) //获取高度宽度 
            this.context = this.canvas.getContext("2d");            this.values = [];            this.last = this.width - 1;//最后一个值的索引
            for (var i = 0; i < this.width; i++) {//初始化值
                this.values.push(this.height);
            }            this.draw = function (value) {                this.value = value;//记录当前值
                this.context.clearRect(0, 0, this.width, this.height);//清空
                this.context.beginPath();//开辟新的绘制路径
                this.context.moveTo(0, this.height);//绘制起点 
                for (var i = 0; i <this.last; i++) {                    this.values[i] = this.values[i + 1];//移动索引值
                    this.context.lineTo(i, this.values[i]);//结束位置
                }                this.values[this.last] = this.height * (100 - value) / 100;//获取最后索引一个值
                this.context.lineTo(this.last, this.values[this.last]);//设置最后一个索引位置
                this.context.lineTo(i, this.height);//绘制结束
                this.context.fillStyle = &#39; rgb(0, 255, 255)&#39;;//填充绘制区域的颜色  
                this.context.fill();//填充
            }
        }        var demo = new fillLineChart("demo");        var val = 0
        setInterval(function () {
            val = rand(rand(20, 50), 60);            document.getElementById(&#39;title&#39;).innerHTML = `示例(${val})`
            demo.draw(val);
        }, 100);        function rand(begin, end) {            return Math.floor(Math.random() * (end - begin)) + begin;
        }    </script></body></html>

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3.Canvas enhancement=>[Example]

<!DOCTYPE html><html><head>
   <meta charset="UTF-8">
   <title>示例3</title>
   <style>
       #title {margin: 2px;            font-family: Helvetica, Arial, sans-serif;            font-size: 9px;            font-weight: bold;            line-height: 15px;            color: rgb(0, 255, 255);} 
       #demo {margin: 2px} 
       span.col {            width: 1px;            height: 100%;            float: left;            opacity: 0.9;            background: rgb(0, 0, 34);}    </style></head><body>
   <label ><input type="checkbox" onclick="demo.isFull=this.checked" checked/>填充显示</label>
   <div style=" opacity: 0.9; cursor: pointer; position: absolute; top: 30px;margin: 10px; background: rgb(0, 0, 34);">
       <div id="title"></div>
       <canvas id="demo"></canvas>
   </div>
   <script>
       function lineChart(o) {            this.id = o.id;            this.canvas = document.getElementById(o.id);            this.color = o.color || &#39;rgb(0, 255, 255)&#39;;            this.value = 0;            this.isFull = o.isFull || false;//是否填充颜色
           this.canvas.width = this.width = o.width || (this.canvas.clientWidth);//获取绑定宽度
           this.canvas.height = this.height = o.height || (this.canvas.clientHeight);//获取高度宽度 
           this.context = this.canvas.getContext("2d");            this.values = [];            this.last = this.width - 1;//最后一个值的索引
           for (var i = 0; i < this.width; i++) {//初始化值
               this.values.push(this.height);
           }            this.draw = function (value) {                this.value = value;//记录当前值
               this.context.clearRect(0, 0, this.width, this.height);//清空
               this.context.beginPath();//开辟新的绘制路径
               this.context.moveTo(0, this.isFull ? this.height : this.values[1]);//绘制起点 
               for (var i = 0; i < this.last; i++) {                    this.values[i] = this.values[i + 1];//移动索引值
                   this.context.lineTo(i, this.values[i]);//结束位置
               }                this.values[this.last] = this.height * (100 - value) / 100;//获取最后索引一个值
               this.context.lineTo(this.last, this.values[this.last]);//设置最后一个索引位置
               if (this.isFull) {                    this.context.lineTo(i, this.height);//绘制结束
                   this.context.fillStyle = this.color;//填充绘制区域的颜色
                   this.context.fill();//填充
               } else {                    this.context.strokeStyle = this.color;                    this.context.stroke();
               }
           }
       }        var demo = new lineChart({            id: "demo",            width: "74",            height: "30",            isFull: true,
       });        var val = 0
       setInterval(function () {
           val = rand(rand(20, 50), 60);            document.getElementById(&#39;title&#39;).innerHTML = `示例(${val})`
           demo.draw(val);
       }, 100);        function rand(begin, end) {            return Math.floor(Math.random() * (end - begin)) + begin;
       }    </script></body> </html>

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I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!