Implementation code for displaying progress of HTML5 upload files_html5 tutorial skills

Here we are combining Asp.net MVC as the server, you can also use other server languages. Let’s look at the HTML of this fragment:

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The code is as follows:

@using (Html.BeginForm("Upload", "Home", FormMethod.Post, new { enctype = "multipart/form-data" , id="form1"}))
{

Upload Image:

< ;div id="fileSize">

}

The related Javascript is like this:

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The code is as follows:

function fileSelected() {
var file = document.getElementById('fileToUpload').files[0];
if (file) {
var fileSize = 0;
if (file.size > 1024 * 1024)
fileSize = (Math.round(file.size * 100 / (1024 * 1024)) / 100).toString () 'MB';
else
fileSize = (Math.round(file.size * 100 / 1024) / 100).toString() 'KB';
document.getElementById('fileName') .innerHTML = 'Name: ' file.name;
document.getElementById('fileSize').innerHTML = 'Size: ' fileSize;
document.getElementById('fileType').innerHTML = 'Type: ' file .type;
}
}
function uploadFile() {
var fd = new FormData();
fd.append("fileToUpload", document.getElementById('fileToUpload'). files[0]);
var xhr = new XMLHttpRequest();
xhr.upload.addEventListener("progress", uploadProgress, false);
xhr.addEventListener("load", uploadComplete, false) ;
xhr.addEventListener("error", uploadFailed, false);
xhr.addEventListener("abort", uploadCanceled, false);
xhr.open("POST", "Home/Upload") ;
xhr.send(fd);
}
function uploadProgress(evt) {
if (evt.lengthComputable) {
var percentComplete = Math.round(evt.loaded * 100 / evt.total);
document.getElementById('progressNumber').innerHTML = percentComplete.toString() '%';
}
else {
document.getElementById('progressNumber').innerHTML = 'unable to compute';
}
}
function uploadComplete(evt) {
/* This event is raised when the server send back a response */
alert(evt.target .responseText);
}
function uploadFailed(evt) {
alert("There was an error attempting to upload the file.");
}
function uploadCanceled(evt) {
alert("The upload has been canceled by the user or the browser dropped the connection.");
}

The above is the native Javascript function that executes fileSelected in the onchange event , after clicking the button, the uploadFile function is executed. Here, XMLHttpRequest is used to implement ajax uploading files. Note that the code will work in Firefox 14, IE 9 does not currently support the file api, you can participate here. The server-side code is very simple:

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The code is as follows:

public class HomeController : Controller
{
public ActionResult Index()
{
return View();
}
///

/// Uploads the specified files .
///

/// The files.
/// ActionResult[HttpPost]
public ActionResult Upload(HttpPostedFileBase[] fileToUpload)
{
foreach (HttpPostedFileBase file in fileToUpload)
{
string path = System.IO.Path.Combine (Server.MapPath("~/App_Data"), System.IO.Path.GetFileName(file.FileName));
file.SaveAs(path);
}
ViewBag.Message = "File( s) uploaded successfully";
return RedirectToAction("Index");
}
}

Author: Petter Liu