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
在此处查找“异步处理文件的上载过程”：https://developer.mozilla.org/en-US/docs/Using_files_from_web_applications
链接中的示例
<?php
if (isset($_FILES['myFile'])) {
// Example:
move_uploaded_file($_FILES['myFile']['tmp_name'], "uploads/" . $_FILES['myFile']['name']);
exit;
}
?><!DOCTYPE html>
<html>
<head>
<title>dnd binary upload</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script type="text/javascript">
function sendFile(file) {
var uri = "/index.php";
var xhr = new XMLHttpRequest();
var fd = new FormData();
xhr.open("POST", uri, true);
xhr.onreadystatechange = function() {
if (xhr.readyState == 4 && xhr.status == 200) {
// Handle response.
alert(xhr.responseText); // handle response.
}
};
fd.append('myFile', file);
// Initiate a multipart/form-data upload
xhr.send(fd);
}
window.onload = function() {
var dropzone = document.getElementById("dropzone");
dropzone.ondragover = dropzone.ondragenter = function(event) {
event.stopPropagation();
event.preventDefault();
}
dropzone.ondrop = function(event) {
event.stopPropagation();
event.preventDefault();
var filesArray = event.dataTransfer.files;
for (var i=0; i<filesArray.length; i++) {
sendFile(filesArray[i]);
}
}
}
</script>
</head>
<body>
<div>
<div id="dropzone" style="margin:30px; width:500px; height:300px; border:1px dotted grey;">Drag & drop your file here...</div>
</div>
</body>
</html>
其他回答
使用|HTML5的readAsDataURL（）或一些base64编码器将文件转换为base64。在这里摆弄
var reader = new FileReader();
reader.onload = function(readerEvt) {
var binaryString = readerEvt.target.result;
document.getElementById("base64textarea").value = btoa(binaryString);
};
reader.readAsBinaryString(file);
然后检索：
window.open("data:application/octet-stream;base64," + base64);
为此，我建议使用Fine Uploader插件。您的JavaScript代码为：
$(document).ready(function() {
$("#uploadbutton").jsupload({
action: "addFile.do",
onComplete: function(response){
alert( "server response: " + response);
}
});
});
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
};
}
}
在此处查找“异步处理文件的上载过程”：https://developer.mozilla.org/en-US/docs/Using_files_from_web_applications
链接中的示例
<?php
if (isset($_FILES['myFile'])) {
// Example:
move_uploaded_file($_FILES['myFile']['tmp_name'], "uploads/" . $_FILES['myFile']['name']);
exit;
}
?><!DOCTYPE html>
<html>
<head>
<title>dnd binary upload</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script type="text/javascript">
function sendFile(file) {
var uri = "/index.php";
var xhr = new XMLHttpRequest();
var fd = new FormData();
xhr.open("POST", uri, true);
xhr.onreadystatechange = function() {
if (xhr.readyState == 4 && xhr.status == 200) {
// Handle response.
alert(xhr.responseText); // handle response.
}
};
fd.append('myFile', file);
// Initiate a multipart/form-data upload
xhr.send(fd);
}
window.onload = function() {
var dropzone = document.getElementById("dropzone");
dropzone.ondragover = dropzone.ondragenter = function(event) {
event.stopPropagation();
event.preventDefault();
}
dropzone.ondrop = function(event) {
event.stopPropagation();
event.preventDefault();
var filesArray = event.dataTransfer.files;
for (var i=0; i<filesArray.length; i++) {
sendFile(filesArray[i]);
}
}
}
</script>
</head>
<body>
<div>
<div id="dropzone" style="margin:30px; width:500px; height:300px; border:1px dotted grey;">Drag & drop your file here...</div>
</div>
</body>
</html>
注意：此答案已过时，现在可以使用XHR上载文件。
不能使用XMLHttpRequest（Ajax）上载文件。可以使用iframe或Flash模拟效果。优秀的jQuery表单插件，通过iframe发布文件以获得效果。
