CanvasRenderingContext2D.stroke()

在此页

句法
范例
规范
浏览器兼容性
另请参阅
相关话题

CanvasRenderingContext2D .stroke() method of the Canvas 2D API strokes (outlines) the current or given path with the current stroke style.

Strokes are aligned to the center of a path; in other words, half of the stroke is drawn on the inner side, and half on the outer side.

The stroke is drawn using the non-zero winding rule , which means that path intersections will still get filled.

句法

void ctx.stroke();
void ctx.stroke(path);

参数

path: Path2D path to stroke.

范例

A simple stroked rectangle

This example creates a rectangle using the rect() method, and then draws it to the canvas using stroke() .

HTML

<canvas id="canvas"></canvas>

JavaScript

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
ctx.rect(10, 10, 150, 100);
ctx.stroke();

结果

Re-stroking paths

Typically, you'll want to call beginPath() for each new thing you want to stroke. If you don't, the previous sub-paths will remain part of the current path, and get stroked every time you call the stroke() method. In some cases, however, this may be the desired effect.

HTML

<canvas id="canvas"></canvas>

JavaScript

This code strokes the first path three times, the second path two times, and the third path only once.

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
// First sub-path
ctx.lineWidth = 26;
ctx.strokeStyle = 'orange';
ctx.moveTo(20, 20);
ctx.lineTo(160, 20);
ctx.stroke();
// Second sub-path
ctx.lineWidth = 14;
ctx.strokeStyle = 'green';
ctx.moveTo(20, 80);
ctx.lineTo(220, 80);
ctx.stroke();
// Third sub-path
ctx.lineWidth = 4;
ctx.strokeStyle = 'pink';
ctx.moveTo(20, 140);
ctx.lineTo(280, 140);
ctx.stroke();

结果

Stroking and filling

If you want to both stroke and fill a path, the order in which you perform these actions will determine the result. In this example, the square on the left is drawn with the stroke on top of the fill. The square on the right is drawn with the fill on top of the stroke.

HTML

<canvas id="canvas"></canvas>

JavaScript

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
ctx.lineWidth = 16;
ctx.strokeStyle = 'red';
// Stroke on top of fill
ctx.beginPath();
ctx.rect(25, 25, 100, 100);
ctx.fill();
ctx.stroke();
// Fill on top of stroke
ctx.beginPath();
ctx.rect(175, 25, 100, 100);
ctx.stroke();
ctx.fill();

结果

规范

规范	状态	注释
HTML 实时标准 The definition of 'CanvasRenderingContext2D.stroke' in that specification.	实时标准

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`stroke`	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
`路径` 参数	Chrome Yes	Edge ≤18	Firefox 31	IE No	Opera Yes	Safari No	WebView Android Yes	Chrome Android Yes	Firefox Android 31	Opera Android ?	Safari iOS ?	Samsung Internet Android Yes

图例

完整支持
不支持
兼容性未知 ?

另请参阅

The interface defining this method: CanvasRenderingContext2D

元数据

最后修改： 2019 年 3 月 23 日

在此页

句法

参数

范例

A simple stroked rectangle

HTML

JavaScript

结果

Re-stroking paths

HTML

JavaScript

结果

Stroking and filling

HTML

JavaScript

结果

规范

浏览器兼容性

图例

另请参阅

相关话题