CanvasRenderingContext2D.font - Web APIs 编辑

The CanvasRenderingContext2D.font property of the Canvas 2D API specifies the current text style to use when drawing text. This string uses the same syntax as the CSS font specifier.

Syntax

ctx.font = value;

Options

value

A DOMString parsed as CSS font value. The default font is 10px sans-serif.

Examples

Using a custom font

In this example we use the font property to specify a custom font weight, size, and family.

HTML

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

JavaScript

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');

ctx.font = 'bold 48px serif';
ctx.strokeText('Hello world', 50, 100);

Result

Loading fonts with the CSS Font Loading API

With the help of the FontFace API, you can explicitly load fonts before using them in a canvas.

let f = new FontFace('test', 'url(x)');

f.load().then(function() {
  // Ready to use the font in a canvas context
});

Specifications

Browser compatibility

BCD tables only load in the browser

Gecko-specific notes

• In Gecko-based browsers, such as Firefox, a non-standard and deprecated property ctx.mozTextStyle is implemented besides this property. Use ctx.font instead.
• In Gecko, when setting a system font as the value of a canvas 2D context's font (e.g., menu), getting the font value used to fail to return the expected font (it returns nothing). This is fixed in Firefox's Quantum/Stylo parallel CSS engine, released in Firefox 57 (bug 1374885).

See also

• The interface defining this property: CanvasRenderingContext2D