~~~ function getBase64Image(img) { var canvas = document.createElement("canvas"); var width = img.width; var height = img.height; if (width > height) { if (width > 100) { height = Math.round(height *= 100 / width); width = 100; } } else { if (height > 100) { width = Math.round(width *= 100 / height); height = 100; } } canvas.width = width; /*设置新的图片的宽度*/ canvas.height = height; /*设置新的图片的长度*/ var ctx = canvas.getContext("2d"); ctx.drawImage(img, 0, 0, width, height); /*绘图*/ var dataURL = canvas.toDataURL("image/png", 0.8); return dataURL.replace("data:image/png;base64,", ""); //return dataURL; } ~~~