本文实例为大家分享了js+canvas实现画板功能的具体代码，供大家参考，具体内容如下
1.实现了画图，改变画笔粗细，改变画笔颜色，清屏功能
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>画板</title> <link rel="shortcut icon" type="image/x-icon" href="img/an.ico" /> <link rel="stylesheet" type="text/css" href="css/drow.css" /> </head> <body> <canvas id="mycanvas" width="1100px" height="660px"></canvas> <div class="tool"> 画笔颜色:<input type="color" name="color1" id="color1"/><br /> 画笔粗细:<input type="range" name="range1" id="range1"min="1" max="20"/><br /> <button class="btn">清屏</button> </div> </body> <script src="/UploadFiles/2021-04-02/drow.js">*{ margin: 0; padding: 0; text-align: left; -moz-user-select: none; -ms-user-select: none; -webkit-user-select: none; } #mycanvas{ border: 2px solid deepskyblue; } .tool{ width: 260px; height: 100%; position: fixed; right: 0; top: 0; background-color: #CCCCCC; }//获取对象 var mycanvas = document.getElementById("mycanvas"); var color1 = document.getElementById("color1"); var range1 = document.getElementById("range1"); var btn = document.getElementsByClassName("btn")[0]; var contxt = mycanvas.getContext("2d"); btn.onclick=function () { contxt.clearRect(0,0,1200,660); } var flag = false; var x = 0, y = 0; // 鼠标点下事件 mycanvas.onmousedown = function(event) { flag = true; // 获取鼠标点下的开始位置 var x = event.clientX - mycanvas.offsetLeft; var y = event.clientY - mycanvas.offsetTop; contxt.beginPath(); // 开始新建路径 contxt.strokeStyle = color1.value; // 获得颜色赋值给画笔 contxt.lineCap="round"; contxt.lineWidth = range1.value; // 获得画笔宽度赋值给画笔 contxt.moveTo(x, y); // 开始位置 } // 鼠标移动事件 mycanvas.onmousemove = function(event) { // 获取鼠标在移动的位置 var mX = event.clientX - mycanvas.offsetLeft; var mY = event.clientY - mycanvas.offsetTop; if (flag) { contxt.lineTo(mX, mY); // 移动途中和结束位置 contxt.stroke(); // 结束渲染画布 } } // 鼠标松开事件 mycanvas.onmouseup = function() { flag = false; }以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。