html 在线显示文件大小,HTML5_纯JS实现上传文件显示文件大小，文件信息，上传进度_不使用JS库...

前台 html

上传

前台JS

function fileSelected() {

var file = document.getElementById(‘_netLogo‘).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("_netLogo", document.getElementById(‘_netLogo‘).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.setRequestHeader("Content-type", "application/x-www-form-urlencoded");

xhr.open("POST", "/User/WNetEdit2_test");

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.");

}

后台 测试函数

public string WNetEdit2_test()

{

var f = Request.Files[0];

string path = System.IO.Path.Combine(Server.MapPath("~/App_Data"), System.IO.Path.GetFileName(f.FileName));

f.SaveAs(path);

return "File(s) uploaded successfully";

}

原文：http://www.cnblogs.com/90nice/p/4080307.html