說明：使用Ajax方式上傳，文件不能過大，最好小于三四百兆，因為過多的連續(xù)Ajax請求會使后臺崩潰，獲取InputStream中數(shù)據(jù)會為空，尤其在Google瀏覽器測試過程中。
1.簡單分段讀取文件為Blob，ajax上傳到服務(wù)器
<div class="container">
<div class="panel panel-default">
<div class="panel-heading">分段讀取文件：</div>
<div class="panel-body">
<input type="file" id="file" />
<blockquote style="word-break:break-all;"></blockquote>
</div>
</div>
</div>
JS：
/*
* 分段讀取文件為blob ，并使用ajax上傳到服務(wù)器
* 分段上傳exe文件會拋出異常
*/
var fileBox = document.getElementById('file');
file.onchange = function () {
//獲取文件對象
var file = this.files[0];
var reader = new FileReader();
var step = 1024 * 1024;
var total = file.size;
var cuLoaded = 0;
console.info("文件大小：" + file.size);
var startTime = new Date();
//讀取一段成功
reader.onload = function (e) {
//處理讀取的結(jié)果
var loaded = e.loaded;
//將分段數(shù)據(jù)上傳到服務(wù)器
uploadFile(reader.result, cuLoaded, function () {
console.info('loaded:' + cuLoaded + 'current:' + loaded);
//如果沒有讀完，繼續(xù)
cuLoaded += loaded;
if (cuLoaded < total) {
readBlob(cuLoaded);
} else {
console.log('總共用時：' + (new Date().getTime() - startTime.getTime()) / 1000);
cuLoaded = total;
}
});
}
//指定開始位置，分塊讀取文件
function readBlob(start) {
//指定開始位置和結(jié)束位置讀取文件
//console.info('start:' + start);
var blob = file.slice(start, start + step);
reader.readAsArrayBuffer(blob);
}
//開始讀取
readBlob(0);
//關(guān)鍵代碼上傳到服務(wù)器
function uploadFile(result, startIndex, onSuccess) {
var blob = new Blob([result]);
//提交到服務(wù)器
var fd = new FormData();
fd.append('file', blob);
fd.append('filename', file.name);
fd.append('loaded', startIndex);
var xhr = new XMLHttpRequest();
xhr.open('post', '../ashx/upload2.ashx', true);
xhr.onreadystatechange = function () {
if (xhr.readyState == 4 && xhr.status == 200) {
// var data = eval('(' + xhr.responseText + ')');
console.info(xhr.responseText);
if (onSuccess)
onSuccess();
}
}
//開始發(fā)送
xhr.send(fd);
}
}
后臺代碼：
/// <summary>
/// upload2 的摘要說明
/// </summary>
public class upload2 : IHttpHandler
{
LogHelper.LogHelper _log = new LogHelper.LogHelper();
int totalCount = 0;
public void ProcessRequest(HttpContext context)
{
HttpContext _Context = context;
//接收文件
HttpRequest req = _Context.Request;
if (req.Files.Count <= 0)
{
WriteStr("獲取服務(wù)器上傳文件失敗");
return;
}
HttpPostedFile _file = req.Files[0];
//獲取參數(shù)
// string ext = req.Form["extention"];
string filename = req.Form["filename"];
//如果是int 類型當(dāng)文件大的時候會出問題 最大也就是 1.9999999990686774G
int loaded = Convert.ToInt32(req.Form["loaded"]);
totalCount += loaded;
string newname = @"F:\JavaScript_Solution\H5Solition\H5Solition\Content\TempFile\&;;
newname += filename;
//接收二級制數(shù)據(jù)并保存
Stream stream = _file.InputStream;
if (stream.Length <= 0)
throw new Exception("接收的數(shù)據(jù)不能為空");
byte[] dataOne = new byte[stream.Length];
stream.Read(dataOne, 0, dataOne.Length);
FileStream fs = new FileStream(newname, FileMode.Append, FileAccess.Write, FileShare.Read, 1024);
try
{
fs.Write(dataOne, 0, dataOne.Length);
}
finally
{
fs.Close();
stream.Close();
}
_log.WriteLine((totalCount + dataOne.Length).ToString());
WriteStr("分段數(shù)據(jù)保存成功");
}
private void WriteStr(string str)
{
HttpContext.Current.Response.Write(str);
}
public bool IsReusable
{
get
{
return true;
}
}
2.分段讀取文件為blob ，并使用ajax上傳到服務(wù)器，追加中止、繼續(xù)功能操作
<div class="container">
<div class="panel panel-default">
<div class="panel-heading">分段讀取文件：</div>
<div class="panel-body">
<input type="file" id="file" />
<br />
<input type="button" value="中止" onclick="stop();" /> 
<input type="button" value="繼續(xù)" onclick="containue();" />
<br />
<progress id="progressOne" max="100" value="0" style="width:400px;"></progress>
<blockquote id="Status" style="word-break:break-all;"></blockquote>
</div>
</div>
</div>
JS:
/*
* 分段讀取文件為blob ，并使用ajax上傳到服務(wù)器
* 使用Ajax方式提交上傳數(shù)據(jù)文件大小應(yīng)該有限值，最好500MB以內(nèi)
* 原因短時間過多的ajax請求，Asp.Net后臺會崩潰獲取上傳的分塊數(shù)據(jù)為空
* 取代方式，長連接或WebSocket
*/
var fileBox = document.getElementById('file');
var reader = null; //讀取操作對象
var step = 1024 * 1024 * 3.5; //每次讀取文件大小
var cuLoaded = 0; //當(dāng)前已經(jīng)讀取總數(shù)
var file = null; //當(dāng)前讀取的文件對象
var enableRead = true;//標(biāo)識是否可以讀取文件
fileBox.onchange = function () {
//獲取文件對象
file = this.files[0];
var total = file.size;
console.info("文件大小：" + file.size);
var startTime = new Date();
reader = new FileReader();
//讀取一段成功
reader.onload = function (e) {
//處理讀取的結(jié)果
var result = reader.result;
var loaded = e.loaded;
if (enableRead == false)
return false;
//將分段數(shù)據(jù)上傳到服務(wù)器
uploadFile(result, cuLoaded, function () {
console.info('loaded:' + cuLoaded + '----current:' + loaded);
//如果沒有讀完，繼續(xù)
cuLoaded += loaded;
if (cuLoaded < total) {
readBlob(cuLoaded);
} else {
console.log('總共用時：' + (new Date().getTime() - startTime.getTime()) / 1000);
cuLoaded = total;
}
//顯示結(jié)果進(jìn)度
var percent = (cuLoaded / total) * 100;
document.getElementById('Status').innerText = percent;
document.getElementById('progressOne').value = percent;
});
}
//開始讀取
readBlob(0);
//關(guān)鍵代碼上傳到服務(wù)器
function uploadFile(result, startIndex, onSuccess) {
var blob = new Blob([result]);
//提交到服務(wù)器
var fd = new FormData();
fd.append('file', blob);
fd.append('filename', file.name);
fd.append('loaded', startIndex);
var xhr = new XMLHttpRequest();
xhr.open('post', '../ashx/upload2.ashx', true);
xhr.onreadystatechange = function () {
if (xhr.readyState == 4 && xhr.status == 200) {
if (onSuccess)
onSuccess();
} else if (xhr.status == 500) {
//console.info('請求出錯，' + xhr.responseText);
setTimeout(function () {
containue();
}, 1000);
}
}
//開始發(fā)送
xhr.send(fd);
}
}
//指定開始位置，分塊讀取文件
function readBlob(start) {
//指定開始位置和結(jié)束位置讀取文件
var blob = file.slice(start, start + step);
reader.readAsArrayBuffer(blob);
}
//中止
function stop() {
//中止讀取操作
console.info('中止，cuLoaded：' + cuLoaded);
enableRead = false;
reader.abort();
}
//繼續(xù)
function containue() {
console.info('繼續(xù)，cuLoaded：' + cuLoaded);
enableRead = true;
readBlob(cuLoaded);
}
后臺代碼同上
3.分段讀取文件為二進(jìn)制數(shù)組 ，并使用ajax上傳到服務(wù)器
使用二進(jìn)制數(shù)組傳遞的方式，效率特別低，最終文件還與原始大小有些偏差
HTML內(nèi)容同上
JS：
/*
* 分段讀取文件為二進(jìn)制數(shù)組 ，并使用ajax上傳到服務(wù)器
* 使用二進(jìn)制數(shù)組傳遞的方式，效率特別低，最終文件還與原始大小有些偏差
*/
var fileBox = document.getElementById('file');
var reader = new FileReader(); //讀取操作對象
var step = 1024 * 1024; //每次讀取文件大小
var cuLoaded = 0; //當(dāng)前已經(jīng)讀取總數(shù)
var file = null; //當(dāng)前讀取的文件對象
var enableRead = true;//標(biāo)識是否可以讀取文件
fileBox.onchange = function () {
//獲取文件對象
if (file == null) //如果賦值多次會有丟失數(shù)據(jù)的可能
file = this.files[0];
var total = file.size;
console.info("文件大小：" + file.size);
var startTime = new Date();
//讀取一段成功
reader.onload = function (e) {
//處理讀取的結(jié)果
var result = reader.result;
var loaded = e.loaded;
if (enableRead == false)
return false;
//將分段數(shù)據(jù)上傳到服務(wù)器
uploadFile(result, cuLoaded, function () {
console.info('loaded:' + cuLoaded + '----current:' + loaded);
//如果沒有讀完，繼續(xù)
cuLoaded += loaded;
if (cuLoaded < total) {
readBlob(cuLoaded);
} else {
console.log('總共用時：' + (new Date().getTime() - startTime.getTime()) / 1000);
cuLoaded = total;
}
//顯示結(jié)果進(jìn)度
var percent = (cuLoaded / total) * 100;
document.getElementById('Status').innerText = percent;
document.getElementById('progressOne').value = percent;
});
}
//開始讀取
readBlob(0);
//關(guān)鍵代碼上傳到服務(wù)器
function uploadFile(result, startIndex, onSuccess) {
var array = new Int8Array(result);
console.info(array.byteLength);
//提交到服務(wù)器
var fd = new FormData();
fd.append('file', array);
fd.append('filename', file.name);
fd.append('loaded', startIndex);
var xhr = new XMLHttpRequest();
xhr.open('post', '../ashx/upload3.ashx', true);
xhr.onreadystatechange = function () {
if (xhr.readyState == 4 && xhr.status == 200) {
// console.info(xhr.responseText);
if (onSuccess)
onSuccess();
} else if (xhr.status == 500) {
console.info('服務(wù)器出錯');
reader.abort();
}
}
//開始發(fā)送
xhr.send(fd);
}
}
//指定開始位置，分塊讀取文件
function readBlob(start) {
//指定開始位置和結(jié)束位置讀取文件
var blob = file.slice(start, start + step);
reader.readAsArrayBuffer(blob);
}
//中止
function stop() {
//中止讀取操作
console.info('中止，cuLoaded：' + cuLoaded);
enableRead = false;
reader.abort();
}
//繼續(xù)
function containue() {
console.info('繼續(xù)，cuLoaded：' + cuLoaded);
enableRead = true;
readBlob(cuLoaded);
}
后臺代碼：
/// <summary>
/// upload3 的摘要說明
/// </summary>
public class upload3 : IHttpHandler
{
LogHelper.LogHelper _log = new LogHelper.LogHelper();
int totalCount = 0;
public void ProcessRequest(HttpContext context)
{
HttpContext _Context = context;
//接收文件
HttpRequest req = _Context.Request;
string data = req.Form["file"];
//轉(zhuǎn)換方式一
//int[] intData = data.Split(',').Select(q => Convert.ToInt32(q)).ToArray();
//byte[] dataArray = intData.ToList().ConvertAll(x=>(byte)x).ToArray();
//轉(zhuǎn)換方式二
byte[] dataArray = data.Split(',').Select(q => int.Parse(q)).Select(q => (byte)q).ToArray();
//獲取參數(shù)
string filename = req.Form["filename"];
//如果是int 類型當(dāng)文件大的時候會出問題 最大也就是 1.9999999990686774G
int loaded = Convert.ToInt32(req.Form["loaded"]);
totalCount += loaded;
string newname = @"F:\JavaScript_Solution\H5Solition\H5Solition\Content\TempFile\&;;
newname += filename;
try
{
// 接收二級制數(shù)據(jù)并保存
byte[] dataOne = dataArray;
FileStream fs = new FileStream(newname, FileMode.Append, FileAccess.Write, FileShare.Read, 1024);
try
{
fs.Write(dataOne, 0, dataOne.Length);
}
finally
{
fs.Close();
}
_log.WriteLine((totalCount + dataOne.Length).ToString());
WriteStr("分段數(shù)據(jù)保存成功");
}
catch (Exception ex)
{
throw ex;
}
}
private void WriteStr(string str)
{
HttpContext.Current.Response.Write(str);
}
public bool IsReusable
{
get
{
return false;
}
}
}
總結(jié)
以上所述是小編給大家介紹的HTML5 文件域+FileReader 分段讀取文件并上傳到服務(wù)器，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回復(fù)大家的。在此也非常感謝大家對腳本之家網(wǎng)站的支持！
