canvas画板

1.只有画线功能的画板

<!DOCTYPE html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
	#canvas{ border:2px dashed #0000FF;}
</style>
</head>

<body onkeydown="test()">
<canvas width="600" height="400" id="canvas"></canvas>
<script type="text/javascript">
	var canvas = document.getElementById("canvas");
	var ctx = canvas.getContext("2d");
	ctx.lineWidth = 3;
	ctx.strokeStyle = "red";
	var paint = 0;
	canvas.onmousedown = function(e){
		var mouseX = e.pageX - this.offsetLeft;
		var mouseY = e.pageY - this.offsetTop;
		paint = 1;
		ctx.moveTo(mouseX,mouseY);
	}

	canvas.onmouseup = function(e){
		paint = 0;
	}
	
	canvas.onmousemove = function(e){
		var mouseX = e.pageX - this.offsetLeft;
		var mouseY = e.pageY - this.offsetTop;
		if(paint){
			ctx.lineTo(mouseX,mouseY);
			ctx.stroke();
		}
	}
</script>
</body>
</html>

　　效果图

 

posted @ 2016-07-26 14:19  浅书流年  阅读(152)  评论(0)    收藏  举报