function clipImage(imgUrl, x, y, width, height) { return new Promise((resolve, reject) => { let cvs = document.createElement("canvas"); cvs.width = width; cvs.height = height; var ctx = cvs.getContext('2d'); let _img = new Image(); _img.src = imgUrl; _img.onload = () => { ctx.drawImage(_img, 0 - x, 0 - y); resolve(cvs.toDataURL()); } })}clipImage("./img/loginbg.jpg", 100, 100, 300, 400).then(res => { let __img = document.createElement("img"); __img.src = res; document.body.appendChild(__img);})
