TextMetrics.emHeightAscent - Web APIs 编辑

The read-only emHeightAscent property of the TextMetrics interface is a double giving the distance from the horizontal line indicated by the CanvasRenderingContext2D.textBaseline property to the top of the em square in the line box, in CSS pixels.

Examples

const canvas = document.createElement('canvas');
const ctx = canvas.getContext('2d');
const text = ctx.measureText('foo'); // returns TextMetrics object

text.emHeightAscent; // 7.59765625;

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• TextMetrics