AntD的 upload组件的使用
This commit is contained in:
qianguyihao
parent
4837e80f54
commit
03e8312f52
590
13-React基础/09-AntD框架的upload组件上传图片时遇到的一些坑.md
Normal file
590
13-React基础/09-AntD框架的upload组件上传图片时遇到的一些坑.md
Normal file
@ -0,0 +1,590 @@
|
||||
|
||||
## 前言
|
||||
|
||||
本次做后台管理系统，采用的是 AntD 框架。涉及到图片的上传，用的是AntD的 [upload](https://ant.design/components/upload-cn/) 组件。
|
||||
|
||||
前端做文件上传这个功能，是很有技术难度的。既然框架给我们提供好了，那就直接用呗。结果用的时候，发现 upload 组件的很多bug。
|
||||
|
||||
## 使用 AntD 的 upload 组件做图片的上传
|
||||
|
||||
因为需要上传多张图片，所以采用的是照片墙的形式。上传成功后的界面如下：
|
||||
|
||||
按照官方提供的实例，特此整理出项目开发中的完整写法，亲测有效。代码如下：
|
||||
|
||||
```javascript
|
||||
/* eslint-disable */
|
||||
|
||||
import { Upload, Icon, Modal, Form } from 'antd';
|
||||
|
||||
const FormItem = Form.Item;
|
||||
|
||||
class PicturesWall extends PureComponent {
|
||||
state = {
|
||||
previewVisible: false,
|
||||
previewImage: '',
|
||||
imgList: [],
|
||||
};
|
||||
|
||||
|
||||
handleChange = ({ file, fileList }) => {
|
||||
console.log(JSON.stringify(file)); // file 是当前正在上传的 单个 img
|
||||
console.log(JSON.stringify(fileList)); // fileList 是已上传的全部 img 列表
|
||||
|
||||
this.setState({
|
||||
imgList: fileList,
|
||||
});
|
||||
};
|
||||
|
||||
|
||||
handleCancel = () => this.setState({ previewVisible: false });
|
||||
|
||||
handlePreview = file => {
|
||||
this.setState({
|
||||
previewImage: file.url || file.thumbUrl,
|
||||
previewVisible: true,
|
||||
});
|
||||
};
|
||||
|
||||
|
||||
// 参考链接：https://www.jianshu.com/p/f356f050b3c9
|
||||
handleBeforeUpload = file => {
|
||||
//限制图片 格式、size、分辨率
|
||||
const isJPG = file.type === 'image/jpeg';
|
||||
const isJPEG = file.type === 'image/jpeg';
|
||||
const isGIF = file.type === 'image/gif';
|
||||
const isPNG = file.type === 'image/png';
|
||||
if (!(isJPG || isJPEG || isGIF || isPNG)) {
|
||||
Modal.error({
|
||||
title: '只能上传JPG 、JPEG 、GIF、 PNG格式的图片~',
|
||||
});
|
||||
return;
|
||||
}
|
||||
const isLt2M = file.size / 1024 / 1024 < 2;
|
||||
if (!isLt2M) {
|
||||
Modal.error({
|
||||
title: '超过2M限制 不允许上传~',
|
||||
});
|
||||
return;
|
||||
}
|
||||
return (isJPG || isJPEG || isGIF || isPNG) && isLt2M && this.checkImageWH(file);
|
||||
};
|
||||
|
||||
//返回一个 promise：检测通过则返回resolve；失败则返回reject，并阻止图片上传
|
||||
checkImageWH(file) {
|
||||
let self = this;
|
||||
return new Promise(function(resolve, reject) {
|
||||
let filereader = new FileReader();
|
||||
filereader.onload = e => {
|
||||
let src = e.target.result;
|
||||
const image = new Image();
|
||||
image.onload = function() {
|
||||
// 获取图片的宽高，并存放到file对象中
|
||||
console.log('file width :' + this.width);
|
||||
console.log('file height :' + this.height);
|
||||
file.width = this.width;
|
||||
file.height = this.height;
|
||||
resolve();
|
||||
};
|
||||
image.onerror = reject;
|
||||
image.src = src;
|
||||
};
|
||||
filereader.readAsDataURL(file);
|
||||
});
|
||||
}
|
||||
|
||||
handleSubmit = e => {
|
||||
const { dispatch, form } = this.props;
|
||||
e.preventDefault();
|
||||
form.validateFieldsAndScroll((err, values) => {// values 是form表单里的参数
|
||||
// 点击按钮后，将表单提交给后台
|
||||
dispatch({
|
||||
type: 'mymodel/submitFormData',
|
||||
payload: values,
|
||||
});
|
||||
});
|
||||
};
|
||||
|
||||
render() {
|
||||
const { previewVisible, previewImage, imgList } = this.state; // 从 state 中拿数据
|
||||
const uploadButton = (
|
||||
<div>
|
||||
<Icon type="plus" />
|
||||
<div className="ant-upload-text">Upload</div>
|
||||
</div>
|
||||
);
|
||||
return (
|
||||
<div className="clearfix">
|
||||
<Form onSubmit={this.handleSubmit} hideRequiredMark style={{ marginTop: 8 }}>
|
||||
<FormItem label="工厂图片" {...formItemLayout}>
|
||||
{getFieldDecorator('myImg')(
|
||||
<Upload
|
||||
action="//jsonplaceholder.typicode.com/posts/" // 这个是接口请求
|
||||
data={file => ({ // data里存放的是接口的请求参数
|
||||
param1: myParam1,
|
||||
param2: myParam2,
|
||||
photoCotent: file, // file 是当前正在上传的图片
|
||||
photoWidth: file.height, // 通过 handleBeforeUpload 获取 图片的宽高
|
||||
photoHeight: file.width,
|
||||
})}
|
||||
listType="picture-card"
|
||||
fileList={this.state.imgList}
|
||||
onPreview={this.handlePreview} // 点击图片缩略图，进行预览
|
||||
beforeUpload={this.handleBeforeUpload} // 上传之前，对图片的格式做校验，并获取图片的宽高
|
||||
onChange={this.handleChange} // 每次上传图片时，都会触发这个方法
|
||||
>
|
||||
{this.state.imgList.length >= 9 ? null : uploadButton}
|
||||
</Upload>
|
||||
)}
|
||||
</FormItem>
|
||||
</Form>
|
||||
<Modal visible={previewVisible} footer={null} onCancel={this.handleCancel}>
|
||||
<img alt="example" style={{ width: '100%' }} src={previewImage} />
|
||||
</Modal>
|
||||
</div>
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
export default PicturesWall;
|
||||
|
||||
```
|
||||
|
||||
|
||||
## 上传后，点击图片预览，浏览器卡死的问题
|
||||
|
||||
依据上方的代码，通过 Antd 的 upload 组件将图片上传成功后，点击图片的缩略图，理应可以在当前页面弹出 Modal，预览图片。但实际的结果是，浏览器一定会卡死。
|
||||
|
||||
定位问题发现，原因竟然是：图片上传成功后， upload 会将其转为 base64编码。base64这个字符串太大了，点击图片预览的时候，浏览器在解析一大串字符串，然后就卡死了。详细过程描述如下。
|
||||
|
||||
上方代码中，我们可以把 handleChange(file, fileList)方法中的 `file`、以及 `fileList`打印出来看看。 `file`指的是当前正在上传的 单个 img，`fileList`是已上传的全部 img 列表。 当我上传完 两张图片后， 打印结果如下：
|
||||
|
||||
|
||||
file的打印的结果如下：
|
||||
|
||||
```json
|
||||
{
|
||||
"uid": "rc-upload-1551084269812-5",
|
||||
"width": 600,
|
||||
"height": 354,
|
||||
"lastModified": 1546701318000,
|
||||
"lastModifiedDate": "2019-01-05T15:15:18.000Z",
|
||||
"name": "e30e7b9680634b2c888c8bb513cc595d.jpg",
|
||||
"size": 31731,
|
||||
"type": "image/jpeg",
|
||||
"percent": 100,
|
||||
"originFileObj": {
|
||||
"uid": "rc-upload-1551084269812-5",
|
||||
"width": 600,
|
||||
"height": 354
|
||||
},
|
||||
"status": "done",
|
||||
"thumbUrl": "data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAHQ9qKKlbimcXrIH9o2vH/AC2T+ddPj98v+9RRWsuhnHdk0ar9qb5R0Pb6VPB/qh9aKKiRr0Irnt/vUDr+NFFJCRqWxJik5Pb+dLJ938aKK06mYSdKKKKBH//Z",
|
||||
"response": {
|
||||
"retCode": 0,
|
||||
"imgUrl": "http://qianguyihao.com/opfewfwj098902kpkpkkj976fe.jpg",
|
||||
"photoid": 271850
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
fileList 的打印结果：
|
||||
|
||||
```json
|
||||
[
|
||||
{
|
||||
"uid": "rc-upload-1551084269812-3",
|
||||
"width": 1000,
|
||||
"height": 667,
|
||||
"lastModified": 1501414799000,
|
||||
"lastModifiedDate": "2017-07-30T11:39:59.000Z",
|
||||
"name": "29381f30e924b89914e91b33.jpg",
|
||||
"size": 135204,
|
||||
"type": "image/jpeg",
|
||||
"percent": 100,
|
||||
"originFileObj": {
|
||||
"uid": "rc-upload-1551084269812-3",
|
||||
"width": 1000,
|
||||
"height": 667
|
||||
},
|
||||
"status": "done",
|
||||
"thumbUrl": "data:image/jpeg;base64,/E3ju1tlaK1fzJOnHQU3LsLV7HO6Zrk11MZJ7luT0A4FZuRagi9quvzQQ4iuEJ7ZpqTG4djDsPFl2Lg733f8C4q+YhQ8zoYfGSqoMmfwo5huLL0HjiyPDSYPvxRdC1XQvxeLrB8fvl/OnoLmL9vrdvvYS3NGFVe2YsASOh71JfQyrqV2mXLHOcccVSIYEnDyZO9XXB9KYH//Z",
|
||||
"response": {
|
||||
"retCode": 0,
|
||||
"msg": "success",
|
||||
"imgUrl": "http://qianguyihao.com/hfwpjouiurewnmbhepr689.jpg",
|
||||
}
|
||||
},
|
||||
{
|
||||
"uid": "rc-upload-1551084269812-5",
|
||||
"width": 600,
|
||||
"height": 354,
|
||||
"lastModified": 1546701318000,
|
||||
"lastModifiedDate": "2019-01-05T15:15:18.000Z",
|
||||
"name": "e30e7b9680634b2c888c8bb513cc595d.jpg",
|
||||
"size": 31731,
|
||||
"type": "image/jpeg",
|
||||
"percent": 100,
|
||||
"originFileObj": {
|
||||
"uid": "rc-upload-1551084269812-5",
|
||||
"width": 600,
|
||||
"height": 354
|
||||
},
|
||||
"status": "done",
|
||||
"thumbUrl": "data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAHQ9qKKlbimcXrIH9o2vH/AC2T+ddPj98v+9RRWsuhnHdk0ar9qb5R0Pb6VPB/qh9aKKiRr0Irnt/vUDr+NFFJCRqWxJik5Pb+dLJ938aKK06mYSdKKKKBH//Z",
|
||||
"response": {
|
||||
"retCode": 0,
|
||||
"imgUrl": "http://qianguyihao.com/opfewfwj098902kpkpkkj976fe.jpg",
|
||||
"photoid": 271850
|
||||
}
|
||||
}
|
||||
]
|
||||
```
|
||||
|
||||
|
||||
上方的json数据中，需要做几点解释：
|
||||
|
||||
（1）`response` 字段里面的数据，就是请求接口后，后台返回给前端的数据，里面包含了图片的url链接。
|
||||
|
||||
（2）`status` 字段里存放的是图片上传的实时状态。
|
||||
|
||||
（3）`thumbUrl`字段里面存放的是图片的base64编码。
|
||||
|
||||
这个base64编码非常非常长。当点击图片预览的时候，其实就是加载的 thumbUrl 这个字段里的资源，难怪浏览器会卡死。
|
||||
|
||||
**解决办法**：在 handleChange方法里，图片上传成功后，将 thumbUrl 字段里面的 base64 编码改为真实的图片url。代码实现如下：
|
||||
|
||||
```javascript
|
||||
handleChange = ({ file, fileList }) => {
|
||||
console.log(JSON.stringify(file)); // file 是当前正在上传的 单个 img
|
||||
console.log(JSON.stringify(fileList)); // fileList 是已上传的全部 img 列表
|
||||
|
||||
if (file && file.response && file.response.retCode == 0) {
|
||||
console.log('图片上传成功');
|
||||
fileList.forEach(item => {
|
||||
// 【重要】将 图片的base64替换为图片的url。 这一行一定不会能少。
|
||||
// 图片上传成功后，fileList数组中的 thumbUrl 中保存的是图片的base64字符串，这种情况，导致的问题是：图片上传成功后，点击图片缩略图，浏览器会会卡死。而下面这行代码，可以解决该bug。
|
||||
item.thumbUrl = item.response.imgUrl;
|
||||
});
|
||||
}
|
||||
|
||||
this.setState({
|
||||
imgList: fileList,
|
||||
});
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
## 新需求：编辑现有页面
|
||||
|
||||
上面一段的代码中，我们是在新建的页面中，从零开始上传页面。
|
||||
|
||||
现在有个新的需求：如何编辑现有的页面呢？也就是说说，现有的页面中，是默认有几张图片的。当我编辑这个页面时，可以对现有的图片做增删，也能增加新的图片。
|
||||
|
||||
我的model层代码，是用 redux 写的。实现思路如下：
|
||||
|
||||
|
||||
（1）PicturesWall.js：
|
||||
|
||||
```javascript
|
||||
/* eslint-disable */
|
||||
|
||||
import { Upload, Icon, Modal, Form } from 'antd';
|
||||
|
||||
const FormItem = Form.Item;
|
||||
|
||||
class PicturesWall extends PureComponent {
|
||||
state = {
|
||||
previewVisible: false,
|
||||
previewImage: '',
|
||||
};
|
||||
|
||||
// 页面初始化的时候，从接口拉取默认的图片数据
|
||||
componentDidMount() {
|
||||
const { dispatch } = this.props;
|
||||
dispatch({
|
||||
type: 'mymodel/getAllInfo',
|
||||
payload: { params: xxx },
|
||||
});
|
||||
}
|
||||
|
||||
handleChange = ({ file, fileList }) => {
|
||||
const { dispatch } = this.props;
|
||||
if (file && file.response && file.response.retCode == 0) {
|
||||
console.log('图片上传成功');
|
||||
fileList.forEach(item => {
|
||||
// 【重要】将 图片的base64替换为图片的url。 这一行一定不会能少。
|
||||
// 图片上传成功后，fileList数组中的 thumbUrl 中保存的是图片的base64字符串，这种情况，导致的问题是：图片上传成功后，点击图片缩略图，浏览器会会卡死。而下面这行代码，可以解决该bug。
|
||||
item.thumbUrl = item.response.imgUrl;
|
||||
});
|
||||
}
|
||||
|
||||
dispatch({
|
||||
type: 'mymodel/setImgList',
|
||||
payload: fileList,
|
||||
});
|
||||
};
|
||||
|
||||
handleCancel = () => this.setState({ previewVisible: false });
|
||||
|
||||
handlePreview = file => {
|
||||
this.setState({
|
||||
previewImage: file.url || file.thumbUrl,
|
||||
previewVisible: true,
|
||||
});
|
||||
};
|
||||
|
||||
// 参考链接：https://www.jianshu.com/p/f356f050b3c9
|
||||
handleBeforeUpload = file => {
|
||||
//限制图片 格式、size、分辨率
|
||||
const isJPG = file.type === 'image/jpeg';
|
||||
const isJPEG = file.type === 'image/jpeg';
|
||||
const isGIF = file.type === 'image/gif';
|
||||
const isPNG = file.type === 'image/png';
|
||||
if (!(isJPG || isJPEG || isGIF || isPNG)) {
|
||||
Modal.error({
|
||||
title: '只能上传JPG 、JPEG 、GIF、 PNG格式的图片~',
|
||||
});
|
||||
return;
|
||||
}
|
||||
const isLt2M = file.size / 1024 / 1024 < 2;
|
||||
if (!isLt2M) {
|
||||
Modal.error({
|
||||
title: '超过2M限制 不允许上传~',
|
||||
});
|
||||
return;
|
||||
}
|
||||
return (isJPG || isJPEG || isGIF || isPNG) && isLt2M && this.checkImageWH(file);
|
||||
};
|
||||
|
||||
//返回一个 promise：检测通过则返回resolve；失败则返回reject，并阻止图片上传
|
||||
checkImageWH(file) {
|
||||
let self = this;
|
||||
return new Promise(function(resolve, reject) {
|
||||
let filereader = new FileReader();
|
||||
filereader.onload = e => {
|
||||
let src = e.target.result;
|
||||
const image = new Image();
|
||||
image.onload = function() {
|
||||
// 获取图片的宽高，并存放到file对象中
|
||||
console.log('file width :' + this.width);
|
||||
console.log('file height :' + this.height);
|
||||
file.width = this.width;
|
||||
file.height = this.height;
|
||||
resolve();
|
||||
};
|
||||
image.onerror = reject;
|
||||
image.src = src;
|
||||
};
|
||||
filereader.readAsDataURL(file);
|
||||
});
|
||||
}
|
||||
|
||||
handleSubmit = e => {
|
||||
const { dispatch, form } = this.props;
|
||||
e.preventDefault();
|
||||
form.validateFieldsAndScroll((err, values) => {
|
||||
// values 是form表单里的参数
|
||||
// 点击按钮后，将表单提交给后台
|
||||
dispatch({
|
||||
type: 'mymodel/submitFormData',
|
||||
payload: values,
|
||||
});
|
||||
});
|
||||
};
|
||||
|
||||
render() {
|
||||
const { previewVisible, previewImage } = this.state; // 从 state 中拿数据
|
||||
|
||||
const {
|
||||
mymodel: { imgList }, // 从props中拿到的图片数据
|
||||
} = this.props;
|
||||
|
||||
const uploadButton = (
|
||||
<div>
|
||||
<Icon type="plus" />
|
||||
<div className="ant-upload-text">Upload</div>
|
||||
</div>
|
||||
);
|
||||
return (
|
||||
<div className="clearfix">
|
||||
<Form onSubmit={this.handleSubmit} hideRequiredMark style={{ marginTop: 8 }}>
|
||||
<FormItem label="工厂图片" {...formItemLayout}>
|
||||
{getFieldDecorator('myImg')(
|
||||
<Upload
|
||||
action="//jsonplaceholder.typicode.com/posts/" // 这个是接口请求
|
||||
data={file => ({
|
||||
// data里存放的是接口的请求参数
|
||||
param1: myParam1,
|
||||
param2: myParam2,
|
||||
photoCotent: file, // file 是当前正在上传的图片
|
||||
photoWidth: file.height, // 通过 handleBeforeUpload 获取 图片的宽高
|
||||
photoHeight: file.width,
|
||||
})}
|
||||
listType="picture-card"
|
||||
fileList={imgList} // 改为从 props 里拿图片数据，而不是从 state
|
||||
onPreview={this.handlePreview} // 点击图片缩略图，进行预览
|
||||
beforeUpload={this.handleBeforeUpload} // 上传之前，对图片的格式做校验，并获取图片的宽高
|
||||
onChange={this.handleChange} // 每次上传图片时，都会触发这个方法
|
||||
>
|
||||
{this.state.imgList.length >= 9 ? null : uploadButton}
|
||||
</Upload>
|
||||
)}
|
||||
</FormItem>
|
||||
</Form>
|
||||
<Modal visible={previewVisible} footer={null} onCancel={this.handleCancel}>
|
||||
<img alt="example" style={{ width: '100%' }} src={previewImage} />
|
||||
</Modal>
|
||||
</div>
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
export default PicturesWall;
|
||||
|
||||
```
|
||||
|
||||
（2）mymodel.js:
|
||||
|
||||
```javascript
|
||||
/* eslint-disable */
|
||||
|
||||
import { routerRedux } from 'dva/router';
|
||||
import { message, Modal } from 'antd';
|
||||
import {
|
||||
getTuanList,
|
||||
getAllFactory,
|
||||
getAllFactGoods,
|
||||
createFactShop,
|
||||
updateFactShop,
|
||||
deleteFactShop,
|
||||
updateFactGoodsStatus,
|
||||
queryShopDetail,
|
||||
createFactGoods,
|
||||
} from '../services/api';
|
||||
import { trim, getCookie } from '../utils/utils';
|
||||
|
||||
export default {
|
||||
namespace: 'factory',
|
||||
|
||||
state: {
|
||||
form: {},
|
||||
list: [],
|
||||
listDetail: [],
|
||||
goodsList: [],
|
||||
goodsListDetail: [],
|
||||
pagination: {
|
||||
pageSize: 10,
|
||||
total: 0,
|
||||
current: 1,
|
||||
},
|
||||
imgList: [], //图片
|
||||
},
|
||||
subscriptions: {
|
||||
setup({ dispatch, history }) {
|
||||
history.listen(location => {
|
||||
if (location.pathname !== '/xx/xxx') return;
|
||||
if (!location.state || !location.state.xxxId) return;
|
||||
dispatch({
|
||||
type: 'fetch',
|
||||
payload: location.state,
|
||||
});
|
||||
});
|
||||
},
|
||||
},
|
||||
|
||||
effects: {
|
||||
// 接口。获取所有工厂店的列表 (步骤02)
|
||||
*getAllInfo({ payload }, { select, call, put }) {
|
||||
yield put({
|
||||
type: 'form',
|
||||
payload,
|
||||
});
|
||||
console.log('params:' + JSON.stringify(payload));
|
||||
|
||||
let params = {};
|
||||
params = payload;
|
||||
|
||||
const response = yield call(getAllFactory, params);
|
||||
|
||||
console.log('smyhvae response:' + JSON.stringify(response));
|
||||
if (response.error) return;
|
||||
yield put({
|
||||
type: 'allInfo',
|
||||
payload:
|
||||
(response.data &&
|
||||
response.data.map(item => ({
|
||||
xx1: item.yy1,
|
||||
xx2: item.yy2,
|
||||
}))) ||
|
||||
[],
|
||||
});
|
||||
|
||||
// response 里包含了接口返回给前端的默认图片数据
|
||||
if (response && response.data && response.data[0] && response.data[0].my_jpg) {
|
||||
let tempImgList = response.data[0].my_jpg.split(',');
|
||||
let imgList = [];
|
||||
|
||||
if (tempImgList.length > 0) {
|
||||
tempImgList.forEach(item => {
|
||||
imgList.push({
|
||||
uid: item,
|
||||
name: 'xxx.png',
|
||||
status: 'done',
|
||||
thumbUrl: item,
|
||||
});
|
||||
});
|
||||
}
|
||||
|
||||
// 通过 redux的方式 将 默认图片 传给 imgList
|
||||
console.log('smyhvae payload imgList:' + JSON.stringify(imgList));
|
||||
yield put({
|
||||
type: 'setImgList',
|
||||
payload: imgList,
|
||||
});
|
||||
}
|
||||
},
|
||||
|
||||
*setImgList({ payload }, { call, put }) {
|
||||
console.log('smyhvae model setImgList');
|
||||
yield put({
|
||||
type: 'getImgList',
|
||||
payload,
|
||||
});
|
||||
},
|
||||
},
|
||||
|
||||
reducers: {
|
||||
allInfo(state, action) {
|
||||
return {
|
||||
...state,
|
||||
list: action.payload,
|
||||
};
|
||||
},
|
||||
getImgList(state, action) {
|
||||
return {
|
||||
...state,
|
||||
imgList: action.payload,
|
||||
};
|
||||
},
|
||||
},
|
||||
};
|
||||
|
||||
```
|
||||
|
||||
大功告成。
|
||||
|
||||
|
||||
本文感谢 ld 同学的支持。
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user