JS_0027：獲取canvas圖片的base64編碼

1，

 

 

 

 

<canvas id="canvas" width="5" height="5"></canvas>

可以用這樣的方式獲取一個 data-URL

var canvas = document.getElementById("canvas");
var dataURL = canvas.toDataURL();
console.log(dataURL);
// "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNby
// blAAAADElEQVQImWNgoBMAAABpAAFEI8ARAAAAAElFTkSuQmCC"


設置jpegs圖片的質量
var fullQuality = canvas.toDataURL("image/jpeg", 1.0);
// data:image/jpeg;base64,/9j/4AAQSkZJRgABAQ...9oADAMBAAIRAxEAPwD/AD/6AP/Z"
var mediumQuality = canvas.toDataURL("image/jpeg", 0.5);
var lowQuality = canvas.toDataURL("image/jpeg", 0.1);

 

去掉base64前綴