input file文件转base64格式

html

<input ref="fileinput" type="file" style="position:absolute; clip:rect(0 0 0 0);" accept="image/png, image/jpeg, image/gif, image/jpg" @change="uploadImg($event)">

js

uploadImg (e) {
            const file = e.target.files[0];
            this.fileType = file.type
            if (!['image/png', 'image/jpg', 'image/gif', 'image/jpeg'].includes(this.fileType)) {
                this.$Message.error('请上传正确的图片')
                return
            }
            if (file.size > 20 * 1024 * 1024) {
                this.$Message.error('请选择20M以内的图片')
                return
            }
            if (typeof FileReader === 'function') {
                const reader = new FileReader();
                reader.readAsDataURL(file);
                reader.onload = (event) => {
                    var Base64Val = event.target.result;
                    console.log( Base64Val)
                }
            } else {
                alert('对不起，您的浏览器暂不支持此功能！');
            }
        }