JQuery ajax 在 asp.net mvc 中的上传文件

You can't upload files via ajax, you need to use an iFrame or some other trickery to do a full postback. This is mainly due to security concerns.

Here's a decent write-up including a sample project using SWFUpload and ASP.Net MVC by Steve Sanderson. It's the first thing I read getting this working properly with Asp.Net MVC (I was new to MVC at the time as well), hopefully it's as helpful for you.

Upload files using AJAX in ASP.Net MVC

Things have changed since HTML5

JavaScript

document.getElementById('uploader').onsubmit = function () {
var formdata = new FormData(); //FormData object
var fileInput = document.getElementById('fileInput');
//Iterating through each files selected in fileInput
for (i = 0; i < fileInput.files.length; i++) {
//Appending each file to FormData object
formdata.append(fileInput.files[i].name, fileInput.files[i]);
}
//Creating an XMLHttpRequest and sending
var xhr = new XMLHttpRequest();
xhr.open('POST', '/Home/Upload');
xhr.send(formdata);
xhr.onreadystatechange = function () {
if (xhr.readyState == 4 && xhr.status == 200) {
alert(xhr.responseText);
}
}
return false;
}

Controller

public JsonResult Upload()
{
for (int i = 0; i < Request.Files.Count; i++)
{
HttpPostedFileBase file = Request.Files[i]; //Uploaded file
//Use the following properties to get file's name, size and MIMEType
int fileSize = file.ContentLength;
string fileName = file.FileName;
string mimeType = file.ContentType;
System.IO.Stream fileContent = file.InputStream;
//To save file, use SaveAs method
file.SaveAs(Server.MapPath("~/")+ fileName ); //File will be saved in application root
}
return Json("Uploaded " + Request.Files.Count + " files");
}

EDIT : The HTML

<form id="uploader">
<input id="fileInput" type="file" multiple>
<input type="submit" value="Upload file" />
</form>

If you posting form using ajax then you can not send image using $.ajax method, you have to use classic xmlHttpobject method for saving image, other alternative of it use submit type instead of button

AJAX file uploads are now possible by passing a FormData object to the data property of the $.ajax request.

As the OP specifically asked for a jQuery implementation, here you go:

<form id="upload" enctype="multipart/form-data" action="@Url.Action("JsonSave", "Survey")" method="POST">
<input type="file" name="fileUpload" id="fileUpload" size="23" /><br />
<button>Upload!</button>
</form>

$('#upload').submit(function(e) {
e.preventDefault(); // stop the standard form submission


$.ajax({
url: this.action,
type: this.method,
data: new FormData(this),
cache: false,
contentType: false,
processData: false,
success: function (data) {
console.log(data.UploadedFileCount + ' file(s) uploaded successfully');
},
error: function(xhr, error, status) {
console.log(error, status);
}
});
});

public JsonResult Survey()
{
for (int i = 0; i < Request.Files.Count; i++)
{
var file = Request.Files[i];
// save file as required here...
}
return Json(new { UploadedFileCount = Request.Files.Count });
}

More information on FormData at MDN

I have a sample like this on vuejs version: v2.5.2

<form action="url" method="post" enctype="multipart/form-data">
<div class="col-md-6">
<input type="file" class="image_0" name="FilesFront" ref="FilesFront" />
</div>
<div class="col-md-6">
<input type="file" class="image_1" name="FilesBack" ref="FilesBack" />
</div>
</form>
<script>
Vue.component('v-bl-document', {
template: '#document-item-template',
props: ['doc'],
data: function () {
return {
document: this.doc
};
},
methods: {
submit: function () {
event.preventDefault();


var data = new FormData();
var _doc = this.document;
Object.keys(_doc).forEach(function (key) {
data.append(key, _doc[key]);
});
var _refs = this.$refs;
Object.keys(_refs).forEach(function (key) {
data.append(key, _refs[key].files[0]);
});


debugger;
$.ajax({
type: "POST",
data: data,
url: url,
cache: false,
contentType: false,
processData: false,
success: function (result) {
//do something
},


});
}
}
});
</script>