html5-canvas lineTo（路径命令）
示例
context.lineTo(endX, endY)
从当前笔位置绘制一条线段以协调[endX，endY]
<!doctype html>
<html>
<head>
<style>
body{ background-color:white; }
#canvas{border:1px solid red; }
</style>
<script>
window.onload=(function(){
//获取对canvas元素及其上下文的引用
var canvas=document.getElementById("canvas");
var ctx=canvas.getContext("2d");
//论点
var startX=25;
var startY=20;
var endX=125;
var endY=20;
// Draw a single line segment drawn using "moveTo" and "lineTo" commands
ctx.beginPath();
ctx.moveTo(startX,startY);
ctx.lineTo(endX,endY);
ctx.stroke();
}); //结束window.onload
</script>
</head>
<body>
<canvas id="canvas" width=200 height=150></canvas>
</body>
</html>您可以组合多个.lineTo命令以绘制多段线。例如，您可以装配3个线段以形成三角形。
<!doctype html>
<html>
<head>
<style>
body{ background-color:white; }
#canvas{border:1px solid red; }
</style>
<script>
window.onload=(function(){
//获取对canvas元素及其上下文的引用
var canvas=document.getElementById("canvas");
var ctx=canvas.getContext("2d");
//论点
var topVertexX=50;
var topVertexY=20;
var rightVertexX=75;
var rightVertexY=70;
var leftVertexX=25;
var leftVertexY=70;
//一组线段绘制为使用
// "moveTo" 和多个 "lineTo" commands
ctx.beginPath();
ctx.moveTo(topVertexX,topVertexY);
ctx.lineTo(rightVertexX,rightVertexY);
ctx.lineTo(leftVertexX,leftVertexY);
ctx.lineTo(topVertexX,topVertexY);
ctx.stroke();
}); //结束window.onload
</script>
</head>
<body>
<canvas id="canvas" width=200 height=150></canvas>
</body>
</html>