Why won't my multiple rectangles draw in the canvas?
<!DOCTYPE html>
<html xmlns="">
<head>
<title></title>
<script src="Scripts/jquery-1.9.1.min.js"></script>
</head>
<body>
<canvas id="myCanvas" width="500" height="500" style="border:1px solid red">
<p>Your browser doesn't support canvas.</p>
</canvas>
</body>
</html>
<script type ="text/javascript">
function Shape(x, y, w, h, fill) {
this.x = x;
this.y = y;
this.w = w;
this.h = h;
this.fill = fill;
}
// get canvas element.
var elem = document.getElementById('myCanvas');
// check if context exist
if (elem.getContext) {
var myRect = [];
myRect.push(new Shape(10, 0, 25, 25, "#333"))
myRect.push(new Shape(0, 40, 39, 25, "#333"))
myRect.push(new Shape(0, 80, 100, 25, "#333"))
context = elem.getContext('2d');
for (i in myRect) {
//console.log(x);
context.fillRect(i.x, i.y, i.w, i.h)
}
//// x, y, width, height
//context.fillRect(0, 0, 50, 50);
//// x, y, width, height
//context.fillRect(75, 0, 50, 50);
}
</script>
Thanks for help.
Why won't my multiple rectangles draw in the canvas?
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
<script src="Scripts/jquery-1.9.1.min.js"></script>
</head>
<body>
<canvas id="myCanvas" width="500" height="500" style="border:1px solid red">
<p>Your browser doesn't support canvas.</p>
</canvas>
</body>
</html>
<script type ="text/javascript">
function Shape(x, y, w, h, fill) {
this.x = x;
this.y = y;
this.w = w;
this.h = h;
this.fill = fill;
}
// get canvas element.
var elem = document.getElementById('myCanvas');
// check if context exist
if (elem.getContext) {
var myRect = [];
myRect.push(new Shape(10, 0, 25, 25, "#333"))
myRect.push(new Shape(0, 40, 39, 25, "#333"))
myRect.push(new Shape(0, 80, 100, 25, "#333"))
context = elem.getContext('2d');
for (i in myRect) {
//console.log(x);
context.fillRect(i.x, i.y, i.w, i.h)
}
//// x, y, width, height
//context.fillRect(0, 0, 50, 50);
//// x, y, width, height
//context.fillRect(75, 0, 50, 50);
}
</script>
Thanks for help.
Share Improve this question edited May 19, 2016 at 16:31 Yass 2,6683 gold badges15 silver badges21 bronze badges asked Mar 5, 2013 at 9:20 Hello-WorldHello-World 9,54524 gold badges90 silver badges157 bronze badges 1- 1 I'll take a look at your code in a second but just wanted to let you know that the jCanvas plugin for jQuery simplifies drawing on the canvas a lot. You may want to take a look at it. :) – James Coyle Commented Mar 5, 2013 at 9:30
2 Answers
Reset to default 16Ok, so you were almost there.
When you iterate round your array of rectangles, you are iterating over the array key not the objects themselves (see How to Loop through plain JavaScript object with objects as members?).
Plus, as @jimjimmy1995 pointed out, you need to set the fill using .fillStyle as .fillRect does not have a fill parameter.
This code will work:
function Shape(x, y, w, h, fill) {
this.x = x;
this.y = y;
this.w = w;
this.h = h;
this.fill = fill;
}
// get canvas element.
var elem = document.getElementById('myCanvas');
// check if context exist
if (elem.getContext) {
var myRect = [];
myRect.push(new Shape(10, 0, 25, 25, "#333"));
myRect.push(new Shape(0, 40, 39, 25, "#333"));
myRect.push(new Shape(0, 80, 100, 25, "#333"));
context = elem.getContext('2d');
for (var i in myRect) {
oRec = myRect[i];
context.fillStyle = oRec.fill;
context.fillRect(oRec.x, oRec.y, oRec.w, oRec.h);
}
}
Don't you need to give it the fill color?
context.fillStyle = i.fill;
context.fillRect(i.x,i.y,i.w,i.h);