示例一：矩形
<!DOCTYPE html><head> <meta charset=utf-8> <title>HTML5画线、圆、矩形</title> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script> </head> <script> $(document).ready(function(){ var c=document.getElementById("drawbox"); var draw=c.getContext("2d"); //获取2d内容的引用，调用绘图API draw.fillStyle="#ff0000"; //方式一指定填充颜色 draw.fillRect(0,0,300,100); //坐标和长宽 draw.fillStyle="rgba(0,0,255,0.5)"; //方式二rgb+透明度 draw.fillRect(400,0,100,100); //坐标和长宽 }) </script> </body> <canvas id="drawbox" width="500" height="500"></canvas> </body> </html>
示例二：线
<!DOCTYPE html><head> <meta charset=utf-8> <title>HTML5画线、圆、矩形</title> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script> </head> <script> $(document).ready(function(){ var c=document.getElementById("drawbox"); var draw=c.getContext("2d"); //获取2d内容的引用，调用绘图API
draw.strokeStyle="#000000"; //指定绘图线颜色 draw.moveTo(10,10); //起始位置 draw.lineTo(150,10); //终止位置 draw.lineTo(10,50); //结束前继续之前的结束点连接 draw.lineTo(10,50);
draw.lineTo(10,10); draw.stroke(); //结束 }) </script> </body> <canvas id="drawbox" width="500" height="500"></canvas> </body> </html>
示例三：圆
<!DOCTYPE html><head> <meta charset=utf-8> <title>HTML5画线、圆、矩形</title> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script> </head> <script> $(document).ready(function(){ var c=document.getElementById("drawbox"); var draw=c.getContext("2d"); //获取2d内容的引用，调用绘图API draw.fillStyle="red"; //颜色 draw.beginPath(); //从新画 draw.arc(50,50,50,0,Math.PI*2,true); //圆心x坐标|圆心y坐标|直径|始|PI为圆周率，Math.PI*2为画圆|true为时针方向：逆时针，0为顺时针， draw.closePath(); //结束 draw.fill(); }) </script> </body> <canvas id="drawbox" width="500" height="500"></canvas> </body> </html>
示例四：渐变
<!DOCTYPE html><head> <meta charset=utf-8> <title>HTML5画线、圆、矩形</title> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script> </head> <script> $(document).ready(function(){ var c=document.getElementById("drawbox"); var draw=c.getContext("2d"); //获取2d内容的引用，调用绘图API //指定渐变区块 var grd=draw.createLinearGradient(50,50,200,50); //坐标，长宽 grd.addColorStop(0,"black"); //起点颜色 grd.addColorStop(1,"green"); //终点颜色 draw.fillStyle=grd; //设为填充样式 draw.fillRect(50,50,200,50); //填充进矩形内 }) </script> </body> <canvas id="drawbox" width="500" height="500"></canvas> </body> </html>
同理所得~~自己尝试下吧
