html5 canvas裁剪區域

時間 2019-12-11

原文原文鏈接

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>canvas裁剪區域</title>
<script src="js/modernizr.js"></script>
</head>

<body>
<script type="text/javascript">
window.addEventListener('load',eventWindowLoaded,false);
function eventWindowLoaded(){
	canvasApp();
}
function canvasSupport(){
	return Modernizr.canvas;
}
function canvasApp(){
	if(!canvasSupport()){
		return;
	}else{
		var theCanvas = document.getElementById('canvas')
		var context = theCanvas.getContext("2d")

	}
	drawScreen();
	function drawScreen(){
		context.fillStyle = "green";
		context.fillRect(10,10,200,200);
		context.save();
		context.beginPath();
		
		context.rect(0,0,50,50);
		context.clip();
		//紅色圓
		context.beginPath();
		context.strokeStyle="red";
		context.lineWidth=5;
		context.arc(100,100,100,(Math.PI/180)*0,(Math.PI/180)*360,false);
		//整理
		context.stroke();
		context.closePath();
		context.restore();
		//再次裁剪整個畫布
		context.beginPath();
		context.rect(0,0,200,200);
		context.clip();
		//繪製一個沒有裁剪的藍線
		context.beginPath();
		context.strokeStyle="blue";
		context.lineWidth=5;
		context.arc(100,100,50,(Math.PI/180)*0,(Math.PI/180)*360,false);
		//整圓
		context.stroke();
		context.closePath();
		
		
		
	}
		
}


</script>
<canvas id="canvas" width="500" height="500">
你的瀏覽器沒法使用canvas
若有問題，請在下方發送你問題，我看到會解答！！
</canvas>
</body>
</html>

首先有個200*200的矩形是綠色的javascript

而後裁剪50*50.。下面那個圓弧只有50*50的區域內了html

而後再切換回200*200java

而後那個藍色的圓又看到了面試

大概的意思就是這樣canvas

最近忙着面試啥的搞得沒時間把個人canvas整理一下！瀏覽器

如今開始繼續整理！！！ui