Actually, I am able to do it using img.onload function. Something I got from 'HTML5 Canvas - How to Draw a line over an image background?'. But I need to draw image without using img from onload function which is like this:
var imagePaper = new Image();
imagePaper.onload = function(){
context.drawImage(imagePaper,100, 20, 500,500);
};
imagePaper.src = "images/main_timerand3papers.png";
}
But I want to able draw rectangle over canvas simply attaching img src above canvas, just as:
<body>
<img id="scream" src="my.jpg" alt="The Scream" width="220" height="277">
<p>Canvas:</p>
<canvas id="myCanvas" width="500" height="500" >
Your browser does not support the HTML5 canvas tag.</canvas>
But I'm unable to draw line over img in canvas, either img is drawing or shape is hiding behind. This is my full code:
<!DOCTYPE html>
<head>
<title>Playing YouTube video on HTML5 canvas</title>
<meta name="viewport" content="user-scalable=no, initial-scale=1.0, maximum-scale=1.0, width=device-width" />
<style type="text/css">
body {
margin: 0px;
padding: 0px;
}
</style>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
</head>
<body>
<img id="scream" src="my.jpg" alt="The Scream" width="220" height="277">
<p>Canvas:</p>
<canvas id="myCanvas" width="500" height="500" >
Your browser does not support the HTML5 canvas tag.</canvas>
<script>
var c=document.getElementById("myCanvas");
var ctx=c.getContext("2d");
var img=document.getElementById("scream");
ctx.drawImage(img,10,10);
var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d');
context.beginPath();
context.rect(188, 50, 200, 100);
context.fillStyle = 'yellow';
context.fill();
context.lineWidth = 7;
context.strokeStyle = 'black';
context.stroke();
</script>
</body>
</html>
See Question&Answers more detail:
os 与恶龙缠斗过久,自身亦成为恶龙；凝视深渊过久,深渊将回以凝视…
