文件无刷新上传 asp.net javascript 文件无刷新上传实例代码

时间:2021-03-17 人气:0

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在新增数据项的时候，用ajax实现无刷新提交，但上传文件的时候，由于数据类型原因，不能将页面的<asp:FileUpload>中以字符串值的方式传到js里调用。我一共找到了两个方法予以解决，实现无刷新上传。
第一种方法：利用js的ADODB.Stream，将文件先转换成流，再通过js上传到服务器，这样有个好处就是可以上传超大文件，并且由于是数据流，可以支持断点续传、方便显示上传进度等人性化功能。唯一的缺点是要客户端浏览器需要设置安全级别，或者安装相关ActiveX控件（这个控件自己做的，加载到页面中）。
相关代码：
文件有：1个前台页面：upload.html、 1个js控制：upload.js、 1个后台处理页面：Accept.aspx(Accept.aspx.cs)
代码文件如下：
upload.html

复制代码代码如下:

 
<html xmlns="http://www.w3.org/1999/xhtml" > 
<head runat="server"> 
<title>无标题页</title> 
<script src="upload.js" src="upload.js" language="jscript" type="text/jscript"></script> 
</head> 
<body> 
<form id="form1" runat="server"> 
<div style="width:100%"> 
<input type="file" id="hidFilePath" /> 
<input type="button" id="ok" onclick="BeginUpLoadFile('0', true)" title="上传" value="UpLoad"/> 
</div> 
<div id="lblLeavingsTime">TIME</div> 
<div id="returnInfo">Info</div> 
</form> 
</body> 
</html> 

upload.js

复制代码代码如下:

 
var g_XMLHttp = null; 
var g_Stream = new ActiveXObject('ADODB.Stream'); 
var g_SendCount = 0; 
var g_TotalCount = 0; 
var g_FileSize = 0; 
var g_UpFileType = 0 ; 
var g_BlockSize = 1024 * 100; //每段分为100K 
var fileExtName = "" ; //文件后缀名 
var g_PauseFlag = false; 
var g_BeginTime = null; 
var g_guageFlag = false ; 
var Nfilename = "" ; 
function Init() 
{ 
InitTitleEvent(); 
BeginUpLoadFile(); 
} 
function MoveGuage() 
{ 
var t_Time = new Date(); 
var t_OddTime = Math.ceil((t_Time.getTime() - g_BeginTime.getTime()) / g_SendCount * (g_TotalCount - g_SendCount) / 1000); 
var t_OddTimeString = ''; 
if(t_OddTime >= 3600) 
{ 
t_OddTimeString = Math.floor(t_OddTime / 3600) + '时'; 
t_OddTime %= 3600; 
} 
if(t_OddTime >= 60) 
{ 
t_OddTimeString += Math.floor(t_OddTime / 60) + '分'; 
t_OddTime %= 60; 
} 
document.all.lblLeavingsTime.innerText = t_OddTimeString + t_OddTime + '秒'; 
} 
//第1个参数表示上传的类型，为命名新文件提供参考 
//第2个参数表示要不要显示状态条 
function BeginUpLoadFile(upFileType, guageFlag) 
{ 
if(g_Stream == null) 
{alert("您的机器不支持ADODB.Stream."); } 
else 
{ 
g_guageFlag = guageFlag ; 
g_UpFileType = upFileType; 
g_Stream.Type = 1; 
g_Stream.Open(); 
var pth = document.getElementById("hidFilePath").value ; 
g_Stream.LoadFromFile(pth); 
var fname=pth.split('\\'); 
Nfilename = fname[fname.length-1] ; 
fileExtName = Nfilename.split('.')[1].toLowerCase(); 
g_Stream.position = 0; 
g_SendCount = 1; 
g_FileSize = g_Stream.size ; 
if (upFileType == 0) //上传图片 
{ 
if (g_FileSize > 1024 * 1024 * 2 ) // 不能大于2M 
{ 
document.all.returnInfo.innerText = "文件大小超过2M！" ; 
g_PauseFlag = true; 
return ; 
} 
var str = "bmp,jpg,jpeg,gif,png,icon"; 
if (str.search(fileExtName) == -1) //图片格式不能超出范围 
{ 
document.all.returnInfo.innerText = "文件格式不正确，请选择bmp、jpg、jpeg、gif、png、icon格式图片！" ; 
g_PauseFlag = true; 
return ; 
} 
} 
g_TotalCount = Math.ceil(g_Stream.size / g_BlockSize); 
g_BeginTime = new Date(); 
SendData(); 
} 
} 
function SendData() 
{ 
if(g_PauseFlag) 
{ 
return; 
} 
if(g_SendCount <= g_TotalCount) 
{ 
var t_XMLDOM = null; 
var t_Root = null; 
var t_Node = null; 
var t_Attribute = null; 
t_XMLDOM = new ActiveXObject('Microsoft.XMLDOM'); 
t_XMLDOM.async = false; 
t_XMLDOM.resolveExternals = false; 
t_Node = t_XMLDOM.createProcessingInstruction('xml','version="1.0"'); 
t_XMLDOM.appendChild(t_Node); 
t_Root = t_XMLDOM.createElement('Root'); 
t_XMLDOM.appendChild(t_Root); 
t_XMLDOM.documentElement.setAttribute('xmlns:dt','urn:schemas-microsoft-com:datatypes'); 
t_Node = t_XMLDOM.createElement('Data'); 
t_Node.dataType = 'bin.base64'; 
t_Node.nodeTypedValue = g_Stream.Read(g_BlockSize); 
t_Attribute = t_XMLDOM.createAttribute('upfiletype'); 
t_Attribute.value = g_UpFileType; 
t_Node.setAttributeNode(t_Attribute); 
t_Attribute = t_XMLDOM.createAttribute('fileindex'); 
t_Attribute.value = g_SendCount; 
t_Node.setAttributeNode(t_Attribute); 
t_Attribute = t_XMLDOM.createAttribute('totalcount'); 
t_Attribute.value = g_TotalCount; 
t_Node.setAttributeNode(t_Attribute); 
t_Attribute = t_XMLDOM.createAttribute('filesize'); 
t_Attribute.value = g_FileSize; 
t_Node.setAttributeNode(t_Attribute); 
t_Attribute = t_XMLDOM.createAttribute('blocksize'); 
t_Attribute.value = g_BlockSize; 
t_Node.setAttributeNode(t_Attribute); 
t_Attribute = t_XMLDOM.createAttribute('fileextname'); 
t_Attribute.value = fileExtName; 
t_Node.setAttributeNode(t_Attribute); 
t_Root.appendChild(t_Node); 
g_XMLHttp = new ActiveXObject('Microsoft.XMLHttp'); 
g_XMLHttp.open('POST','AcceptFile.aspx',true); 
g_XMLHttp.onreadystatechange = XMLHttpStateChange; 
g_XMLHttp.send(t_XMLDOM); 
if (g_guageFlag){ MoveGuage(); } 
} 
else 
{ 
var xx = spider.BookFile.FileObj.getFileName() ; 
alert(xx.value) ; 
document.all.lblLeavingsTime.innerText = '0秒'; 
CloseWindow(document.all.cmdClose); 
document.all.returnInfo.innerText = '文件上传完成！'; 
} 
} 
function XMLHttpStateChange() 
{ 
if(g_XMLHttp.readyState == 4) 
{ 
var rstr = g_XMLHttp.responseText ; 
if(rstr == 'OK') 
{ 
g_SendCount++; 
SendData(); 
} 
else 
{ 
document.all.returnInfo.innerText = rstr; 
CloseWindow(document.all.cmdClose); 
} 
} 
} 
function CloseWindow(p_OBJ) 
{ 
g_PauseFlag = true; 
g_Stream.Close(); 
} 

Accept.aspx

复制代码代码如下:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="AcceptFile.aspx.cs" Inherits="commonJS_AcceptFile" %> 

Accept.aspx.cs

复制代码代码如下:

using System; 
using System.Data; 
using System.Configuration; 
using System.Collections; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 
using System.Xml; 
using System.IO; 
using spider.BookFile; //这是自己写的文件类 
public partial class commonJS_AcceptFile : System.Web.UI.Page 
{ 
protected void Page_Load(object sender, EventArgs e) 
{ 
AjaxPro.Utility.RegisterTypeForAjax(typeof(FileObj)); 
XmlDocument t_XmlDocument = new XmlDocument(); 
t_XmlDocument.Load(this.Request.InputStream); 
XmlNode t_XmlNode = t_XmlDocument.SelectSingleNode("Root/Data"); 
FileObj t_FileOBJ = new FileObj(); 
string t_upfiletype = t_XmlNode.Attributes["upfiletype"].Value; 
string t_FileIndex = t_XmlNode.Attributes["fileindex"].Value; 
string t_totalcount = t_XmlNode.Attributes["totalcount"].Value; 
string t_filesize = t_XmlNode.Attributes["filesize"].Value; 
string t_blocksize = t_XmlNode.Attributes["blocksize"].Value; 
string t_fileextname = t_XmlNode.Attributes["fileextname"].Value; 
byte[] t_File = Convert.FromBase64String(t_XmlNode.FirstChild.Value); 
FileObj.upfile myUpFile = new FileObj.upfile(); 
myUpFile.FileCount = t_totalcount; 
myUpFile.FileIndex = t_FileIndex; 
myUpFile.UpFileType = t_upfiletype; 
myUpFile.FileSize = t_filesize; 
myUpFile.BlockSize = t_blocksize; 
myUpFile.ExtName = t_fileextname; 
myUpFile.t_File = t_File; 
FileObj.InsertFileList(myUpFile); 
if (FileObj.getErrMsg == "") 
{ 
this.Response.Write("OK"); 
} 
else 
{ 
this.Response.Write(FileObj.getErrMsg); 
} 
} 
} 

第二种方法：用js动态创建form和iframe上传文件，实现无刷新。优点是代码量小，无需客户端安装控件，缺点就是上传有限制大小，下面看代码：
需要文件有：1个前台页面upload.html、 1个js函数 function upFile、 1个处理文件accept.aspx(accept.aspx.cs)
upload.html

复制代码代码如下:

 
<html xmlns="http://www.w3.org/1999/xhtml" > 
<head runat="server"> 
<title>无标题页</title> 
<script src="upload.js" src="upload.js" language="jscript" type="text/jscript"></script> 
</head> 
<body> 
<form id="form1" runat="server"> 
<div style="width:100%"> 
<iframe name='hidden_frame' id="hidden_frame" style='width:150px; height:50px; display:none;'> </iframe> 
<input type="file" id="hidFilePath" /> 
<input id="upBtn" type="button" class="clearBtn" style="display:none;" value="上传图片" onclick="upFile('hidFilePath');" /> 
</div> 
</form> 
</body> 
</html> 

function upFile

复制代码代码如下:

 
function upFile(ob) 
{ 
var file = document.getElementById(ob) ; 
var newName = "FileName"; //设置文件保存的名字 

var form=document.createElement('form'); 
document.body.appendChild(form); 
form.encoding="multipart/form-data"; 
form.method = "post"; 
form.action= "accept.aspx?nm=" + newName; 
form.target= "hidden_frame"; 
var pos=file.nextSibling; //记住file在旧表单中的的位置 
form.appendChild(file); 
form.submit(); 
pos.parentNode.insertBefore(file,pos); 
document.body.removeChild(form); 
} 

accept.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="up.aspx.cs" Inherits="Member_up" %>
accept.aspx.cs

复制代码代码如下:

 
using System; 
using System.Data; 
using System.Configuration; 
using System.Collections; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 


public partial class Member_up : System.Web.UI.Page 
{ 
protected void Page_Load(object sender, EventArgs e) 
{ 
string mz = HttpContext.Current.Request.QueryString["nm"].ToString(); 
string uperr = ""; 
HttpFileCollection files = HttpContext.Current.Request.Files; 

if (files.Count>0) 
{ uperr = upSingleFile(files[0], mz); } 
else { uperr = "ok"; } 
HttpContext.Current.Session["upInfo"] = uperr; 
Response.Write(uperr); 
} 


//上传文件 
private string upSingleFile(HttpPostedFile file, String theFileName) 
{ 
string infos = ""; 
bool fileOK = false; 

string fileName, fileExtension ; 
fileName = System.IO.Path.GetFileName(file.FileName); 
if (fileName != "") 
{ 
if (file.ContentLength >= 1024 * 1024 * 2) 
{ 
infos = "上传文件太大，目前仅支持2M以内的图片上传！"; 
} 
else 
{ 
fileExtension = System.IO.Path.GetExtension(fileName).ToLower(); 
String[] allowedExtensions = { ".jpg", ".jpeg", ".gif", ".bmp", ".png", ".icon" }; 
for (int i = 0; i < allowedExtensions.Length; i++) 
{ 
if (fileExtension == allowedExtensions[i]) 
{ 
fileOK = true; 
break; 
} 
} 
if (!fileOK) 
{ 
infos = "不支持上传此类型文件！目前支持的图片格式有：jpg|jpeg|gif|bmp|png|icon"; 
} 
else 
{ 
file.SaveAs(System.Web.HttpContext.Current.Request.MapPath("~/books/BookPic/") + theFileName); 
infos = "ok" + theFileName; 
} 
} 
} 
else 
{ 
infos = "没有读取到文件！"; 
} 
return infos; 
} 
} 

以上为我写程序过程中遇到过的问题和探索到的解决方法，写下来一是自己在温习巩固一遍，二来是为了与大家分享，请大家指正需改进之处，以期达到共同进步！

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