📅  最后修改于: 2022-03-11 15:03:53.254000             🧑  作者: Mango
/**
* Resize a base 64 Image
* @param {String} base64 - The base64 string (must include MIME type)
* @param {Number} newWidth - The width of the image in pixels
* @param {Number} newHeight - The height of the image in pixels
*/
function resizeBase64Img(base64, newWidth, newHeight) {
return new Promise((resolve, reject)=>{
var canvas = document.createElement("canvas");
canvas.style.width = newWidth.toString()+"px";
canvas.style.height = newHeight.toString()+"px";
let context = canvas.getContext("2d");
let img = document.createElement("img");
img.src = base64;
img.onload = function () {
context.scale(newWidth/img.width, newHeight/img.height);
context.drawImage(img, 0, 0);
resolve(canvas.toDataURL());
}
});
}