pdf html5 阅读进度,HTML5上传文件显示进度

下面我们使用Html 5的新特性file api实现上传文件，并显示上传文件进度百分比。意图是这样的，当选择文件时，显示当前文件信息。这里我们是结合Asp.net MVC做为服务端，您也可以是其它的服务端语言。让我们看面这个片断的HTML：

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

{

Upload Image:

}

相关的Javascript是这样的：

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.");

}

上面是就原生的Javascript，在onchange事件执行fileSelected的function，在点击button执行了uploadFile的function，这里使用XMLHttpRequest实现ajax上传文件。 注意代码在Firefox 14 可以工作，IE 9目前不支持file api，可以参加这里。 服务端的代码很简单：

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");

}

}