element ui Upload 上传 限制图片宽高

1 upload
2         class="avatar-uploader"
3         :action="action"
4         :show-file-list="false"
5         :before-upload="beforeAvatarUpload">
6       
7     

 1 methods: {
 2     beforeAvatarUpload(file) {
 3       let width = 750;
 4       let height = 1642;
 5       const isSize = new Promise(function (resolve, reject) {
 6         let _URL = window.URL || window.webkitURL;
 7         let img = new Image();
 8         img.onload = function () {
 9           let valid = img.width == width && img.height == height;
10           valid ? resolve() : reject();
11         }
12         img.src = _URL.createObjectURL(file);
13       }).then(() => {
14         return file;
15       }, () => {
16         this.$message({
17           message: `上传图片尺寸只能是${width}*${height}px!请重新选择!`,
18           type: ‘warning‘
19         });
20         return false;//必须加上return false; 才能阻止
21       })
22       return isSize;
23     }
24  },