演示

drag.gif

实现

index.tsx

import React from 'react';
import ReactDOM from 'react-dom';
import { message } from 'antd';
import Dragger from './Dragger';
import 'antd/dist/antd.css';
let props = {
    name: "file",
    action: "http://localhost:8080/upload",
    onChange: (info: any) => {
        if (info.file.status === 'done') {
            message.success(info.file.name + '上传成功！');
        } else if (info.file.status === 'error') {
            message.error(info.file.name + '上传失败！');
        }
    }
}

ReactDOM.render(<Dragger {...props} />, document.getElementById('root'));

types.tsx

export interface UploadInfo {
    file: File & {
        status?: string,
        percent: number,
        _url?: string
    },
    fileList: FileList,
    event?: ProgressEvent
}
export interface DragProps {
    name: string,
    action: string,
    onChange: (uploadInfo: UploadInfo) => void
}

Dragger.tsx

import React, { useState, useCallback, useRef, MutableRefObject, SFC, RefObject, useEffect, DragEvent } from 'react';
import { UploadInfo, DragProps } from './types';
import { Icon, Progress } from 'antd';
import './Dragger.css';

const Dragger: SFC<DragProps> = (props: DragProps) => {
    //function useRef<T = undefined>(): MutableRefObject<T | undefined>;
    let [uploadInfos, setUploadInfos] = useState<UploadInfo[]>([]);
    let dragCotainer: MutableRefObject<HTMLDivElement | undefined> = useRef<HTMLDivElement | undefined>();
    let fileInput: MutableRefObject<HTMLInputElement | undefined> = useRef<HTMLInputElement | undefined>();
    const ondragenter = (e: Event) => {
        e.preventDefault();
        e.stopPropagation();
    }
    const ondragover = (e: Event) => {
        e.preventDefault();
        e.stopPropagation();
    }
    const ondragleave = (e: Event) => {
        e.preventDefault();
        e.stopPropagation();
    };
    const upload = useCallback((fileList: FileList) => {
        for (let i = 0; i < fileList.length; i++) {
            let file: any = fileList[i];
            let formData = new FormData();
            let uploadInfo: UploadInfo = {
                file,
                fileList
            }
            formData.append('filename', file.name);
            formData.append(props.name, file);
            let xhr = new XMLHttpRequest();
            xhr.open('POST', props.action);
            xhr.responseType = 'json';
            xhr.timeout = 1000;
            xhr.upload.onprogress = xhr.onprogress = (e) => {
                file.status = 'progress';
                file.percent = +(e.loaded / e.total * 100).toFixed(2);
                setUploadInfos([...uploadInfos]);
                props.onChange(uploadInfo);
            }
            xhr.ontimeout = xhr.onerror = (e) => {
                file.status = 'error';
                setUploadInfos([...uploadInfos]);
                props.onChange(uploadInfo);
            }
            xhr.onload = () => {
                if (/(png|jpe?g|gif|jfif)/.test(xhr.response.url.split('.').pop())) {
                    console.log(xhr.response.url.split('.').pop());
                    file._url = xhr.response.url;
                }
                file.status = 'done';
                setUploadInfos([...uploadInfos]);
                props.onChange(uploadInfo);
            }
            xhr.send(formData);
            uploadInfos.push(uploadInfo);
        }
        setUploadInfos([...uploadInfos]);
    }, [props, uploadInfos])
    const ondrop = useCallback((e: DragEvent) => {
        e.preventDefault();
        e.stopPropagation();
        if (e.dataTransfer) {
            upload(e.dataTransfer.files);
        }
    }, [upload]);


    useEffect(() => {
        let container = dragCotainer.current!;
        container.addEventListener('dragenter', ondragenter);
        container.addEventListener('dragover', ondragover);
        container.addEventListener('dragleave', ondragleave);
        container.addEventListener('drop', (ondrop as any));
        return () => {
            container.removeEventListener('dragenter', ondragenter);
            container.removeEventListener('dragover', ondragover);
            container.removeEventListener('dragleave', ondragleave);
            container.removeEventListener('drop', (ondrop as any));
        }
    }, [ondrop]);
    return (
        <div className="drag">
            <input multiple type="file" onChange={e => {
                upload(e.currentTarget.files!);
            }} ref={fileInput as RefObject<HTMLInputElement>} />
            <div className="drag-container" onClick={e => fileInput.current!.click()} ref={dragCotainer as RefObject<HTMLDivElement>}>
                <Icon type='inbox' />
                <span>Upload</span>
            </div>
            <div >
                {
                    uploadInfos.map((item, index) => {
                        return <div key={index}>
                            <div>
                                <Icon type={item.file.status === 'progress' ? 'loading' : 'paper-clip'} />
                                <span>{item.file.name}</span>
                            </div>
                            <Progress status={item.file.status === 'error' ? 'exception' : undefined} percent={item.file.percent} />
                            {item.file._url ? <img alt='上传的图片' height={100} src={item.file._url} /> : null}
                        </div>
                    })
                }
            </div>
        </div>
    )
}
export default Dragger;

Dragger.css

.drag{
    margin: 100px auto;
    width:600px ;
}
.drag input[type='file']{
    display: none;
}
.drag-container{
    width: 100%;
    height: 150px;
    background: #fafafa;
    border-radius: 5px;
    border: 1px dashed #ccc;
    transition: all .35s;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    font-size: 20px;
}
.drag-container:hover{
    border-color: #58a;
}

api.js

const Koa = require('koa');
const koaStatic = require('koa-static');
const koaBody = require('koa-body');
const path = require('path');
const fs = require('fs');

const app = new Koa();

app.use(async (ctx, next) => {
    ctx.set('Access-Control-Allow-Origin', '*');
    ctx.set('Access-Control-Allow-Headers', 'Content-Type, Accept');
    ctx.set('Access-Control-Allow-Methods', 'PUT, POST, GET, DELETE, OPTIONS');
    if (ctx.method == 'OPTIONS') {
        ctx.body = 200;
    } else {
        await next();
    }
});

app.use(koaBody({
    formidable: { uploadDir: path.resolve(__dirname, './uploads') },
    multipart: true
})).use(koaStatic(path.resolve(__dirname, './uploads')));

app.use(async (ctx, next) => {
    if (ctx.url === '/upload') {
        let file = ctx.request.files.file;
        let filename = path.basename(file.path) + path.extname(file.name);
        fs.renameSync(file.path, path.join(path.dirname(file.path), filename));
        ctx.body = { url: "http://localhost:8080/" + filename };
    } else {
        await next();
    }
})

app.listen('8080', () => {
    console.log('8080端口服务启动成功！');
})