使用JS实现大风车！
下面附上效果图：
最后附上源码，复制即可用：
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>那年我们一起看过的大风车</title> <style type="text/css"> #box{ border:2px solid #f60; width:800px; height:600px; margin:0 auto; } </style> <script type="text/javascript"> var canvas,context;//画布、上下文 var X,Y;//风车的圆心X坐标、Y坐标 var canvasWidth,canvasHeight;//画布的宽高 var speed = 1;//风车的转速、默认为1 var R = 10;//风车的半径 //初始化页面函数 function init(){ initCanvas(); initParams(); draw(); setInterval(draw,20); } //初始化画布宽高、风车圆心坐标 function initParams(){ canvasWidth = canvas.width; canvasHeight = canvas.height; X = canvasWidth/2; Y = canvasHeight/4; } //设置风的大小 function setSpeed(speed){ this.speed = speed; } //设置风的大小 function setR(R){ this.R = R; } //初始化画布 function initCanvas(){ try{ canvas = document.getElementById("windmill"); context = canvas.getContext("2d"); }catch(e){ document.getElementById("tip_info").innerHTML = "您的浏览器不支持！"; } } //绘制半圆 function drawArc(tangle, style){ context.beginPath(); var trunkGradient = context.createLinearGradient(X, Y, X, Y+4*R); trunkGradient.addColorStop(0, style); trunkGradient.addColorStop(1, '#FFF00F'); context.fillStyle = trunkGradient; context.arc(X - (2*R*Math.cos(tangle)), Y - 2*R*Math.sin(tangle), 2*R, tangle, Math.PI+tangle, true); context.closePath(); context.fill(); context.save(); } //绘制手把柄 function drawHandle(){ var trunkGradient = context.createLinearGradient(X, Y, X+10, Y); trunkGradient.addColorStop(0, '#663300'); trunkGradient.addColorStop(0.4, '#996600'); trunkGradient.addColorStop(1, '#552200'); context.fillStyle = trunkGradient; context.fillRect(X, Y, 0.2*R, 8*R); } //绘制文字 function drawText(){ context.font = "30px 宋体 bold"; context.textAlign = 'center'; context.fillText('那些年我们一起看过的大风车！', X, canvasWidth - 300, 300); } //绘制函数 var tangle = 0; function draw(){ tangle = tangle + (speed*1/32)*Math.PI; context.clearRect(0,0,canvasWidth,canvasHeight); drawHandle(); drawText(); drawArc(tangle,"#552200"); drawArc(tangle+1/2*Math.PI, "#990000"); drawArc(tangle+Math.PI, "#0033FF"); drawArc(tangle+3/2*Math.PI, "#225500"); document.getElementById("tip_info").innerHTML = "转动角度："+parseInt(tangle)+" 当前的风速："+speed; } window.addEventListener("load",init,true); </script> </head> <body> <div id="box"> <canvas id = "windmill" style = "background-color:#001111" width = "800px" height = "600px"></canvas> <div id = "tip_info"></div> <div> <button onClick="setSpeed(0)">停止</button> <button onClick="setSpeed(0.1)">微风</button> <button onClick="setSpeed(0.5)">小风</button> <button onClick="setSpeed(1)">中风</button> <button onClick="setSpeed(2)">大风</button> <button onClick="setSpeed(4)">狂风</button> | <button onClick="setR(5)">小号</button> <button onClick="setR(20)">中号</button> <button onClick="setR(30)">大号</button> <button onClick="setR(35)">超大号</button> </div> </div> </body> </html>
如果有错误的地方，请联系我改正！谢谢！！！