I volontari di MDN non hanno ancora tradotto questo articolo in Italiano. Registrati per tradurlo tu.
The CanvasRenderingContext2D
.strokeStyle
property of the Canvas 2D API specifies the color or style to use for the lines around shapes. The default is #000
(black).
See also the chapter Applying styles and color in the Canvas Tutorial.
Syntax
ctx.strokeStyle = color; ctx.strokeStyle = gradient; ctx.strokeStyle = pattern;
Options
color
- A
DOMString
parsed as CSS<color>
value. gradient
- A
CanvasGradient
object (a linear or radial gradient). pattern
- A
CanvasPattern
object (a repetitive image).
Examples
Using the strokeStyle
property to set a different color
This is just a simple code snippet using the strokeStyle
property to set a different color.
HTML
<canvas id="canvas"></canvas>
JavaScript
var canvas = document.getElementById("canvas"); var ctx = canvas.getContext("2d"); ctx.strokeStyle = "blue"; ctx.strokeRect(10, 10, 100, 100);
Edit the code below and see your changes update live in the canvas:
Playable code
<canvas id="canvas" width="400" height="200" class="playable-canvas"></canvas> <div class="playable-buttons"> <input id="edit" type="button" value="Edit" /> <input id="reset" type="button" value="Reset" /> </div> <textarea id="code" class="playable-code"> ctx.strokeStyle = "blue"; ctx.strokeRect(10, 10, 100, 100);</textarea>
var canvas = document.getElementById("canvas"); var ctx = canvas.getContext("2d"); var textarea = document.getElementById("code"); var reset = document.getElementById("reset"); var edit = document.getElementById("edit"); var code = textarea.value; function drawCanvas() { ctx.clearRect(0, 0, canvas.width, canvas.height); eval(textarea.value); } reset.addEventListener("click", function() { textarea.value = code; drawCanvas(); }); edit.addEventListener("click", function() { textarea.focus(); }) textarea.addEventListener("input", drawCanvas); window.addEventListener("load", drawCanvas);
A strokeStyle
example
This example uses the strokeStyle
property to change the colors of the shapes' outlines. We use the arc()
method to draw circles instead of squares.
var ctx = document.getElementById('canvas').getContext('2d'); for (var i=0;i<6;i++){ for (var 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(); } }
<canvas id="canvas" width="150" height="150"></canvas>
The result looks like this:
Screenshot | Live sample |
---|---|
Specifications
Specification | Status | Comment |
---|---|---|
WHATWG HTML Living Standard The definition of 'CanvasRenderingContext2D.strokeStyle' in that specification. |
Living Standard |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |
WebKit/Blink-specific notes
- In WebKit- and Blink-based browsers, a non-standard and deprecated method
ctx.setStrokeColor()
is implemented besides this property.setStrokeColor(color, optional alpha); setStrokeColor(grayLevel, optional alpha); setStrokeColor(r, g, b, a); setStrokeColor(c, m, y, k, a);
See also
- The interface defining it,
CanvasRenderingContext2D
CanvasGradient
CanvasPattern