最近的项目中有需要限制上传图片的尺寸：
<form id="uploadForm"><input type="file" id="file" @change="uploadImg($event)"></form>
方法如下：
uploadImg(event) { //上传图片const _this = this;let _file = event.target.files[0];let reader = new FileReader();reader.readAsDataURL(_file);reader.onload = function(e) {let image = new Image();image.src = e.target.result;image.onload = function() {let w = this.width;let h = this.height;if (w !== 720 || h !== 360) {_this.$message.info('请上传尺寸为720px*360px的图片');return false;} else {//上传成功//...}}}}
