The CanvasRenderingContext2D.strokeStyle
property of the Canvas 2D API specifies the color, gradient, or pattern to use for the strokes (border lines) around shapes. The default is #000
(black).
For more examples of stroke and fill styles, see the chapter Applying styles and color in the Canvas tutorial.
ctx.strokeStyle = color; ctx.strokeStyle = gradient; ctx.strokeStyle = pattern;
color
DOMString
parsed as CSS <color>
value.gradient
CanvasGradient
object (a linear or radial gradient).pattern
CanvasPattern
object (a repeating image).This example applies a blue stroke color to a rectangle.
<canvas id="canvas"></canvas>
var canvas = document.getElementById('canvas'); var ctx = canvas.getContext('2d'); ctx.strokeStyle = 'blue'; ctx.strokeRect(10, 10, 100, 100);
In this example, we use two for
loops and the arc()
method to draw a grid of circles, each having a different stroke color. To achieve this, we use the two variables i
and j
to generate a unique RGB color for each circle, and only modify the green and blue values. (The red channel has a fixed value.)
var ctx = document.getElementById('canvas').getContext('2d'); for (let i = 0; i < 6; i++) { for (let j = 0; j < 6; j++) { ctx.strokeStyle = `rgb( 0, ${Math.floor(255 - 42.5 * i)}, ${Math.floor(255 - 42.5 * j)})`; ctx.beginPath(); ctx.arc(12.5 + j * 25, 12.5 + i * 25, 10, 0, Math.PI * 2, true); ctx.stroke(); } }
The result looks like this:
Screenshot | Live sample |
---|---|
Specification | Status | Comment |
---|---|---|
HTML Living Standard The definition of 'CanvasRenderingContext2D.strokeStyle' in that specification. | Living Standard |
Desktop | ||||||
---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
Basic support | Yes | 12 | Yes | Yes | Yes | Yes |
Mobile | |||||||
---|---|---|---|---|---|---|---|
Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
Basic support | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
In WebKit- and Blink-based browsers, the non-standard and deprecated method ctx.setStrokeColor()
is implemented in addition to this property.
setStrokeColor(color, optional alpha); setStrokeColor(grayLevel, optional alpha); setStrokeColor(r, g, b, a); setStrokeColor(c, m, y, k, a);
CanvasRenderingContext2D
CanvasGradient
CanvasPattern
© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/strokeStyle