React - 带有文件和字符串的 Axios POST 表单数据

Posted 2023-02-22

【中文标题】React - 带有文件和字符串的 Axios POST 表单数据

【英文标题】：React - Axios POST form data with files and strings

【发布时间】：2019-01-17 21:09:20

【问题描述】：

我必须创建Axios POST，其中body 类型是form-data。有些键是字符串，有些是文件。邮递员要求：

如何添加上传按钮以获取文件进入状态，以及如何发出Axios请求？

【参考方案1】：

import React,  Component  from 'react';
import axios from "axios";

class FileUpload extends Component 

    // API Endpoints
    custom_file_upload_url = `YOUR_API_ENDPOINT_SHOULD_GOES_HERE`;


    constructor(props) 
        super(props);
        this.state = 
            image_file: null,
            image_preview: '',
        
    

    // Image Preview Handler
    handleImagePreview = (e) => 
        let image_as_base64 = URL.createObjectURL(e.target.files[0])
        let image_as_files = e.target.files[0];

        this.setState(
            image_preview: image_as_base64,
            image_file: image_as_files,
        )
    

    // Image/File Submit Handler
    handleSubmitFile = () => 

        if (this.state.image_file !== null)

            let formData = new FormData();
            formData.append('customFile', this.state.image_file);
            // the image field name should be similar to your api endpoint field name
            // in my case here the field name is customFile

            axios.post(
                this.custom_file_upload_url,
                formData,
                
                    headers: 
                        "Authorization": "YOUR_API_AUTHORIZATION_KEY_SHOULD_GOES_HERE_IF_HAVE",
                        "Content-type": "multipart/form-data",
                    ,                    
                
            )
            .then(res => 
                console.log(`Success` + res.data);
            )
            .catch(err => 
                console.log(err);
            )
        
    


    // render from here
    render()  
        return (
            <div>
                /* image preview */
                <img src=this.state.image_preview />

                /* image input field */
                <input
                    type="file"
                    onChange=this.handleImagePreview
                />
                <label>Upload file</label>
                <input type="submit" onClick=this.handleSubmitFile value="Submit"/>
            </div>
        );
    


export default FileUpload;

【参考方案2】：

只需在“文件”类型的输入上触发 onChange 事件中的方法，并以“multipart/form-data”格式发送到服务器：

<Input id="file" type="file" onChange=this.uploadFile />

        let formData = new FormData();
        /*
          Iteate over any file sent over appending the files
          to the form data.
        */
        for( var i = 0; i < this.files.length; i++ )
          let file = this.files[i];
          formData.append('files[' + i + ']', file);
        
        /*
          Make the request to the POST /select-files URL
        */
        axios.post( '/select-files',
          formData,
          
            headers: 
                'Content-Type': 'multipart/form-data'
            
          
        ).then(function()
          console.log('SUCCESS!!');
        )
        .catch(function()
          console.log('FAILURE!!');
        );

【讨论】：

输入不应该在前端可见，只有带有文本 Upload 的按钮。我的问题是如何为上述示例创建Axios post？

这是另一个问题，另一个问题。样式和输入是另一个主题，谷歌足以回答。