HTML5如何实现上传文件显示进度

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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"}))

{

<div class="row">

<label for="file">

Upload Image:</label>

<input type="file" name="fileToUpload" id="fileToUpload" multiple="multiple" onchange="fileSelected();" />

</div>

<div id="fileName">

</div>

<div id="fileSize">

</div>

<div id="fileType">

</div>

<div class="row">

<input type="button" onclick="uploadFile()" value="Upload Image" />

</div>

<div id="progressNumber">

</div>

}

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();

}

/// <summary>

/// Uploads the specified files.

/// </summary>

/// <param name="fileToUpload">The files.</param>

/// <returns>ActionResult</returns>

[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");

}

}

以上是“HTML5如何实现上传文件显示进度”这篇文章的所有内容，感谢各位的阅读！相信大家都有了一定的了解，希望分享的内容对大家有所帮助，如果还想学习更多知识，欢迎关注亿速云行业资讯频道！