HTML canvas measureText()Methods
Examples
Check the width of the font before outputting text on the canvas:
JavaScript：
var c=document.getElementById("myCanvas");
var ctx=c.getContext("2d");
ctx.font="30px Arial";
var txt="Hello World"
ctx.fillText("width:" + ctx.measureText(txt).width,10,50)
ctx.fillText(txt,10,100);
var ctx=c.getContext("2d");
ctx.font="30px Arial";
var txt="Hello World"
ctx.fillText("width:" + ctx.measureText(txt).width,10,50)
ctx.fillText(txt,10,100);
Try it yourself »
Browser Support
Internet Explorer 9, Firefox, Opera, Chrome, and Safari support the measureText() method.
Note:Internet Explorer 8 and earlier versions do not support the <canvas> element.
Definition and Usage
The measureText() method returns an object that contains the width of the specified font in pixels.
Tip:If you need to know the width of the text before it is output to the canvas, use this method.
| JavaScript Syntax: | context.measureText(text).width; |
|---|
Parameter Values
| Parameter | Description |
|---|---|
| text | The text to be measured. |
HTML canvas Reference Manual Other Extensions