我想用jQuery异步上传文件。
$（文档）.ready（函数（）{$（“#uploadbutton”）.click（函数（）{var filename=$（“#file”）.val（）；$.ajax美元({类型：“POST”，url:“addFile.do”，enctype:'多部分/表单数据'，数据：{文件：文件名},成功：函数（）{alert（“上传的数据：”）；}});});});<script src=“https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.0/jquery.min.js“></script><span>文件</span><input type=“file”id=“file”name=“file”size=“10”/><input id=“uploadbutton”type=“button”value=“Upload”/>
我只得到文件名，而不是上传文件。我可以做什么来解决这个问题？
当前回答
要使用Jquery异步上载文件，请执行以下步骤：
步骤1在您的项目中，打开Nuget管理器并添加包（jquery fileupload（只需将其写入搜索框，它就会出现并安装））网址：https://github.com/blueimp/jQuery-File-Upload
步骤2在HTML文件中添加以下脚本，这些脚本已通过运行上述包添加到项目中：
jquery.ui.widget.jsjquery.iframe-transport.jsjquery.filepload.js
步骤3按照以下代码编写文件上传控制：
<input id="upload" name="upload" type="file" />
步骤4将js方法编写为uploadFile，如下所示：
function uploadFile(element) {
$(element).fileupload({
dataType: 'json',
url: '../DocumentUpload/upload',
autoUpload: true,
add: function (e, data) {
// write code for implementing, while selecting a file.
// data represents the file data.
//below code triggers the action in mvc controller
data.formData =
{
files: data.files[0]
};
data.submit();
},
done: function (e, data) {
// after file uploaded
},
progress: function (e, data) {
// progress
},
fail: function (e, data) {
//fail operation
},
stop: function () {
code for cancel operation
}
});
};
步骤5：在就绪功能中，调用元素文件上传，以启动以下过程：
$(document).ready(function()
{
uploadFile($('#upload'));
});
步骤6根据以下内容编写MVC控制器和操作：
public class DocumentUploadController : Controller
{
[System.Web.Mvc.HttpPost]
public JsonResult upload(ICollection<HttpPostedFileBase> files)
{
bool result = false;
if (files != null || files.Count > 0)
{
try
{
foreach (HttpPostedFileBase file in files)
{
if (file.ContentLength == 0)
throw new Exception("Zero length file!");
else
//code for saving a file
}
}
catch (Exception)
{
result = false;
}
}
return new JsonResult()
{
Data=result
};
}
}
其他回答
要使用Jquery异步上载文件，请执行以下步骤：
步骤1在您的项目中，打开Nuget管理器并添加包（jquery fileupload（只需将其写入搜索框，它就会出现并安装））网址：https://github.com/blueimp/jQuery-File-Upload
步骤2在HTML文件中添加以下脚本，这些脚本已通过运行上述包添加到项目中：
jquery.ui.widget.jsjquery.iframe-transport.jsjquery.filepload.js
步骤3按照以下代码编写文件上传控制：
<input id="upload" name="upload" type="file" />
步骤4将js方法编写为uploadFile，如下所示：
function uploadFile(element) {
$(element).fileupload({
dataType: 'json',
url: '../DocumentUpload/upload',
autoUpload: true,
add: function (e, data) {
// write code for implementing, while selecting a file.
// data represents the file data.
//below code triggers the action in mvc controller
data.formData =
{
files: data.files[0]
};
data.submit();
},
done: function (e, data) {
// after file uploaded
},
progress: function (e, data) {
// progress
},
fail: function (e, data) {
//fail operation
},
stop: function () {
code for cancel operation
}
});
};
步骤5：在就绪功能中，调用元素文件上传，以启动以下过程：
$(document).ready(function()
{
uploadFile($('#upload'));
});
步骤6根据以下内容编写MVC控制器和操作：
public class DocumentUploadController : Controller
{
[System.Web.Mvc.HttpPost]
public JsonResult upload(ICollection<HttpPostedFileBase> files)
{
bool result = false;
if (files != null || files.Count > 0)
{
try
{
foreach (HttpPostedFileBase file in files)
{
if (file.ContentLength == 0)
throw new Exception("Zero length file!");
else
//code for saving a file
}
}
catch (Exception)
{
result = false;
}
}
return new JsonResult()
{
Data=result
};
}
}
使用HTML5，您可以使用Ajax和jQuery上传文件。不仅如此，您还可以进行文件验证（名称、大小和MIME类型）或使用HTML5进度标记（或div）处理进度事件。最近我不得不做一个文件上传器，但我不想使用Flash或Iframes或插件，经过一些研究，我想出了解决方案。
HTML：
<form enctype="multipart/form-data">
<input name="file" type="file" />
<input type="button" value="Upload" />
</form>
<progress></progress>
首先，如果需要，可以进行一些验证。例如，在文件的.on（'change'）事件中：
$(':file').on('change', function () {
var file = this.files[0];
if (file.size > 1024) {
alert('max upload size is 1k');
}
// Also see .name, .type
});
现在，单击按钮即可提交$.ajax（）：
$(':button').on('click', function () {
$.ajax({
// Your server script to process the upload
url: 'upload.php',
type: 'POST',
// Form data
data: new FormData($('form')[0]),
// Tell jQuery not to process data or worry about content-type
// You *must* include these options!
cache: false,
contentType: false,
processData: false,
// Custom XMLHttpRequest
xhr: function () {
var myXhr = $.ajaxSettings.xhr();
if (myXhr.upload) {
// For handling the progress of the upload
myXhr.upload.addEventListener('progress', function (e) {
if (e.lengthComputable) {
$('progress').attr({
value: e.loaded,
max: e.total,
});
}
}, false);
}
return myXhr;
}
});
});
正如你所看到的，通过HTML5（以及一些研究）文件上传不仅变得可能，而且非常容易。尝试使用Google Chrome，因为示例中的一些HTML5组件在每个浏览器中都不可用。
对于PHP，请查找https://developer.hyvor.com/php/image-upload-ajax-php-mysql
HTML
<html>
<head>
<title>Image Upload with AJAX, PHP and MYSQL</title>
</head>
<body>
<form onsubmit="submitForm(event);">
<input type="file" name="image" id="image-selecter" accept="image/*">
<input type="submit" name="submit" value="Upload Image">
</form>
<div id="uploading-text" style="display:none;">Uploading...</div>
<img id="preview">
</body>
</html>
JAVASCRIPT语言
var previewImage = document.getElementById("preview"),
uploadingText = document.getElementById("uploading-text");
function submitForm(event) {
// prevent default form submission
event.preventDefault();
uploadImage();
}
function uploadImage() {
var imageSelecter = document.getElementById("image-selecter"),
file = imageSelecter.files[0];
if (!file)
return alert("Please select a file");
// clear the previous image
previewImage.removeAttribute("src");
// show uploading text
uploadingText.style.display = "block";
// create form data and append the file
var formData = new FormData();
formData.append("image", file);
// do the ajax part
var ajax = new XMLHttpRequest();
ajax.onreadystatechange = function() {
if (this.readyState === 4 && this.status === 200) {
var json = JSON.parse(this.responseText);
if (!json || json.status !== true)
return uploadError(json.error);
showImage(json.url);
}
}
ajax.open("POST", "upload.php", true);
ajax.send(formData); // send the form data
}
PHP
<?php
$host = 'localhost';
$user = 'user';
$password = 'password';
$database = 'database';
$mysqli = new mysqli($host, $user, $password, $database);
try {
if (empty($_FILES['image'])) {
throw new Exception('Image file is missing');
}
$image = $_FILES['image'];
// check INI error
if ($image['error'] !== 0) {
if ($image['error'] === 1)
throw new Exception('Max upload size exceeded');
throw new Exception('Image uploading error: INI Error');
}
// check if the file exists
if (!file_exists($image['tmp_name']))
throw new Exception('Image file is missing in the server');
$maxFileSize = 2 * 10e6; // in bytes
if ($image['size'] > $maxFileSize)
throw new Exception('Max size limit exceeded');
// check if uploaded file is an image
$imageData = getimagesize($image['tmp_name']);
if (!$imageData)
throw new Exception('Invalid image');
$mimeType = $imageData['mime'];
// validate mime type
$allowedMimeTypes = ['image/jpeg', 'image/png', 'image/gif'];
if (!in_array($mimeType, $allowedMimeTypes))
throw new Exception('Only JPEG, PNG and GIFs are allowed');
// nice! it's a valid image
// get file extension (ex: jpg, png) not (.jpg)
$fileExtention = strtolower(pathinfo($image['name'] ,PATHINFO_EXTENSION));
// create random name for your image
$fileName = round(microtime(true)) . mt_rand() . '.' . $fileExtention; // anyfilename.jpg
// Create the path starting from DOCUMENT ROOT of your website
$path = '/examples/image-upload/images/' . $fileName;
// file path in the computer - where to save it
$destination = $_SERVER['DOCUMENT_ROOT'] . $path;
if (!move_uploaded_file($image['tmp_name'], $destination))
throw new Exception('Error in moving the uploaded file');
// create the url
$protocol = stripos($_SERVER['SERVER_PROTOCOL'],'https') === true ? 'https://' : 'http://';
$domain = $protocol . $_SERVER['SERVER_NAME'];
$url = $domain . $path;
$stmt = $mysqli -> prepare('INSERT INTO image_uploads (url) VALUES (?)');
if (
$stmt &&
$stmt -> bind_param('s', $url) &&
$stmt -> execute()
) {
exit(
json_encode(
array(
'status' => true,
'url' => $url
)
)
);
} else
throw new Exception('Error in saving into the database');
} catch (Exception $e) {
exit(json_encode(
array (
'status' => false,
'error' => $e -> getMessage()
)
));
}
在使用XMLHttpRequest进行异步上载时，可以传递附加参数和文件名（不依赖flash和iframe）。将附加参数值附加到FormData并发送上载请求。
var formData = new FormData();
formData.append('parameter1', 'value1');
formData.append('parameter2', 'value2');
formData.append('file', $('input[type=file]')[0].files[0]);
$.ajax({
url: 'post back url',
data: formData,
// other attributes of AJAX
});
此外，Syncfusion JavaScript UI文件上传只需使用事件参数即可为该场景提供解决方案。您可以在此处找到文档，并在此处输入链接描述
这是一个老问题，但仍然没有正确答案，因此：
您尝试过jQuery文件上载吗？
下面是上面链接中的一个示例，可以解决您的问题：
$('#fileupload').fileupload({
add: function (e, data) {
var that = this;
$.getJSON('/example/url', function (result) {
data.formData = result; // e.g. {id: 123}
$.blueimp.fileupload.prototype
.options.add.call(that, e, data);
});
}
});
