js实现圆盘记速表

如何利用AmCharts制作的汽车速度计速表，通过设置不同的速度（数字）来动态改变计速表的指针

效果图：

javascript代码：

var chart = AmCharts.makeChart("chartdiv", { "type": "gauge", "theme": "none", "axes": [{ "axisThickness": 1, "axisAlpha": 0.2, "tickAlpha": 0.2, "valueInterval": 20, "bands": [{ "color": "#84b761", "endValue": 90, "startValue": 0 }, { "color": "#fdd400", "endValue": 130, "startValue": 90 }, { "color": "#cc4748", "endValue": 220, "innerRadius": "95%", "startValue": 130 }], "bottomText": "0 km/h", "bottomTextYOffset": -20, "endValue": 320 }], "arrows": [{}] }); window.onload=function(){ chart.arrows[0].setValue(80); chart.axes[0].setBottomText(80 " km/h"); } document.getElementById("btnSure").onclick=function(){ if(document.getElementById("txtNum").value>320){ alert("超出最大值"); return; } if(document.getElementById("txtNum").value<0){ alert("不能低于0"); return; } chart.arrows[0].setValue(document.getElementById("txtNum").value); chart.axes[0].setBottomText(document.getElementById("txtNum").value " km/h"); }

引入JS:

<script type="text/javascript" src="https://www.jb51.net/amcharts.js"></script> <script type="text/javascript" src="https://www.jb51.net/gauge.js"></script> <script type="text/javascript" src="https://www.jb51.net/none.js"></script>