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案例:ajax利用FormData上传文件,事件钩子监控进度时间

案例:ajax利用FormData上传文件,事件钩子监控进度时间

作者: kino2046 | 来源:发表于2020-02-15 21:52 被阅读0次

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <meta name="viewport" content="width=device-width, initial-scale=1.0">

    <meta http-equiv="X-UA-Compatible" content="ie=edge">

    <title>Document</title>

</head>

<body>

    <input type="file" class="myfile" />

    进度:<progress value="0" max="100"></progress> <span class="percent">0%</span>

    速度:<span class="speed">20b/s</span>

    <button>点击上传</button>

    <button>取消上传</button>

</body>

<script>

    let xhr = new XMLHttpRequest();

    let btns = document.querySelectorAll("button");

    let stime;

    let sloaded;

    btns[0].onclick = function () {

        let file = document.querySelector(".myfile").files[0];

        let form = new FormData();

        form.append("myfile", file);

        xhr.open("post", "/fileUpload", true);

        xhr.onload = function () {

            console.log(xhr.responseText);

        }

        xhr.upload.onloadstart = function(){

            console.log("开始上传");

            stime = new Date().getTime();

            sloaded = 0;

        }

        xhr.upload.onprogress = function(evt){

            let endTime = new Date().getTime();

            // 时间差;

            let dTime = (endTime - stime)/1000;

            // 当前时间内上传的文件大小

            let dloaded =  evt.loaded - sloaded;

            let speed = dloaded/dTime;

            let unit = "b/s";

            stime = new Date().getTime();

            sloaded = evt.loaded;

            if(speed/1024>1){

                unit = "kb/s";

                speed = speed/1024;

            }

            if(speed/1024>1){

                unit = "mb/s";

                speed = speed/1024;

            }

            document.querySelector(".speed").innerHTML = speed.toFixed(2)+unit;

            // console.log(speed.toFixed(2));

            // console.log("正在上传");

            // 当前文件上传的大小evt.loaded

            // 需要上传文件的大小

           let percent =  (evt.loaded/evt.total*100).toFixed(0);

        //    console.log(percent);

            document.querySelector("progress").value = percent;

            document.querySelector(".percent").innerHTML = percent+"%";

        }

        xhr.upload.onload = function(){

            console.log("上传成功");

        }

        xhr.upload.onloadend = function(){

            console.log("上传完成");

        }

        xhr.upload.onabort = function(){

            console.log("取消上传");

        }

        xhr.send(form);

    }

    btns[1].onclick = function(){

        xhr.abort();

    }

</script>

</html>


const Koa = require("koa");

const static = require("koa-static");

const Router = require("koa-router");

const koaBody = require("koa-body");

const fs = require("fs");

const usersData = require("./data/users.json");

let app = new Koa();

app.use(static(__dirname+"/static"));

app.use(koaBody({

    multipart:true

}));

let router = new Router();

router.get("/",(ctx,next)=>{

    ctx.body = "hello";

})

router.get("/checkUserName",(ctx,next)=>{

    console.log(ctx.query.username);

    let res =  usersData.find(v=>v.username==ctx.query.username);

    if(res){

        ctx.body = {

            status:1,

            info:"用户名正确"

        };

    }else{

        ctx.body = {

            status:2,

            info:"用户名错误"

        };

    }

})

router.get("/get/:id",(ctx,next)=>{

    console.log(ctx.params);

    ctx.body = {

        status:1,

        info:"请求成功"

    }

})

router.post("/post",(ctx,next)=>{

    console.log(ctx.request.body);

    ctx.body = {

        status:1,

        info:"post请求成功"

    }

})

router.get("/xml",(ctx,next)=>{

    // ctx.set("content-type","text/xml");

    ctx.body = `<?xml version='1.0' encoding='utf-8' ?>

                    <books>

                        <nodejs>

                            <name>nodejs实战</name>

                            <price>56元</price>

                        </nodejs>

                        <react>

                            <name>react入门</name>

                            <price>50元</price>

                        </react>

                    </books>

                `

})

router.post("/upload",(ctx,next)=>{

    console.log(ctx.request.body);

    console.log(ctx.request.files.img);

     let fileData =  fs.readFileSync(ctx.request.files.img.path);

    fs.writeFileSync("static/imgs/"+ctx.request.files.img.name,fileData);

    ctx.body = "请求成功";

})

router.post("/fileUpload",(ctx,next)=>{

    console.log(ctx.request.files);

    let fileData =  fs.readFileSync(ctx.request.files.myfile.path);

    fs.writeFileSync("static/imgs/"+ctx.request.files.myfile.name,fileData);

    ctx.body = "请求成功";

})

app.use(router.routes());

app.listen(3000);


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      本文标题:案例:ajax利用FormData上传文件,事件钩子监控进度时间

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