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Ajax实现上传图像功能

2022-04-11 | 秩名 | 点击:

最终效果展示

xhr发起请求

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<!DOCTYPE html>

<html lang="en">

  

<head>

    <meta charset="UTF-8">

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

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

    <title>Document</title>

    <link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="external nofollow" >

    <script src="https://cdn.staticfile.org/jquery/2.1.1/jquery.min.js"></script>

    <script src="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>

</head>

  

<body>

    <!--1、文件选择框  -->

    <input type="file" id="file1">

    <!-- 2、上传文件的按钮 -->

    <button id="btnupload">上传文件</button>

    <br/>

    <div class="progress" style="width:300px;margin:5px;">

        <div class="progress-bar progress-bar-striped active" style="width: 0%;" id="precent">

            0%

        </div>

    </div>

    <!-- 3、img标签 来显示上传成功以后的图片 -->

    <img alt="" id="img" width="800">

  

    <script>

       var precent = document.querySelector('#precent')

        var btnupload = document.querySelector('#btnupload')

        btnupload.addEventListener('click', function() {

            var files = document.querySelector('#file1').files

            if (files.length <= 0) {

                return alert('请选择要上传的文件')

            }

  

            var fd = new FormData()

            fd.append('avatar', files[0])

            var xhr = new XMLHttpRequest()

  

            xhr.upload.onprogress = function(e) {

                console.log(e);

                if (e.lengthComputable) {

                    var h = Math.ceil((e.loaded / e.total) * 100)

                    precent.style.width = h + '%'

                    precent.innerHTML = h + '%'

                    console.log(h);

                }

            }

            xhr.upload.onload = function() {

                $('#precent').removeClass().addClass('progress-bar progress-bar-success')

            }

  

            xhr.open('post', 'http://www.liulongbin.top:3006/api/upload/avatar')

            xhr.send(fd)

            xhr.onreadystatechange = function() {

                if (xhr.readyState == 4 && xhr.status == 200) {

                    var data = JSON.parse(xhr.responseText)

                    console.log(data);

                    if (data.status == 200) {

                        console.log('上传成功');

                        document.querySelector('#img').src = 'http://www.liulongbin.top:3006' + data.url

                    } else {

                        console.log('上传失败');

                    }

                }

            }

        })

    </script>

</body>

  

</html>

ajax发起请求

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<!DOCTYPE html>

<html lang="en">

  

<head>

    <meta charset="UTF-8">

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

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

    <title>Document</title>

    <script src="jquery.js"></script>

    <style>

        img {

            width: 50px;

            height: 50px;

            display: none;

        }

    </style>

</head>

  

<body>

    <input type="file" id="file1">

    <button id="btnupload">上传文件</button>

    </br>

    <img src="5-121204193R5-50.gif" alt="" id="loading">

    <script>

        $(function() {

            $(document).ajaxStart(function() {

                $('#loading').show()

            })

            $(document).ajaxStop(function() {

                $('#loading').hide()

            })

            $('#btnupload').on('click', function() {

                var files = $('#file1')[0].files

                if (files.length <= 0) {

                    alert('请选择文件')

                }

                console.log('ok');

                var fd = new FormData()

                fd.append('avatar', files[0])

                $.ajax({

                    method: 'POST',

                    url: 'http://www.liulongbin.top:3006/api/upload/avatar',

                    data: fd,

                    processData: false,

                    contentType: false,

                    success: function(res) {

                        console.log(res);

                    }

                })

  

            })

  

        })

    </script>

</body>

  

</html>

原文链接:https://blog.csdn.net/qq_45387575/article/details/124081612
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