HTML5上傳文件顯示進度的實現代碼

2020-03-24 18:50:14

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來源：轉載

供稿：網友

這里我們是結合Asp.net MVC做為服務端，您也可以是其它的服務端語言。讓我們看面這個片斷的HTML：

復制代碼代碼如下:
@using (Html.BeginForm("Upload", "Home", FormMethod.Post, new { enctype = "multipart/form-data" , id="form1"}))
{
div
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
input type="button" html' target='_blank'>value="Upload Image" /
/div
div id="progressNumber"
/div
}

相關的Javascript是這樣的：

復制代碼代碼如下:
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事件執行fileSelected的function，在點擊button執行了uploadFile的function，這里使用XMLHttpRequest實現ajax上傳文件。注意代碼在Firefox 14 可以工作，IE 9目前不支持file api，可以參加這里。服務端的代碼很簡單：

復制代碼代碼如下:
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");
}
}

作者：Petter Liuhtml教程

鄭重聲明：本文版權歸原作者所有，轉載文章僅為傳播更多信息之目的，如作者信息標記有誤，請第一時間聯系我們修改或刪除，多謝。

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