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asp.net+js 实现无刷新上传解析csv文件的代码

2010-05-17 00:00 1101 查看
前阵子工作中用到,贴上代码,仅保留上传有关的代码,发现code其实很少。
上传页面html/js
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml" > 
<head> 
<title></title> 
<script type="text/javascript"> 
function FinishUpload(filePath) { 
document.getElementById("uploadForm").reset(); 
if (!filePath) { 
alert("Import Failed!"); 
} 
else { 
alert("Imported Successfully to " + decodeURIComponent(filePath) + "!"); 
} 
} 
function UploadFile() { 
var arr = document.getElementById("txtFile").value.split('.'); 
var fileType = arr[arr.length - 1]; 
if (fileType.toLowerCase().indexOf("csv") < 0) { 
document.getElementById("uploadForm").reset(); 
alert("Please select a csv file."); 
return false; 
} 
document.getElementById("uploadForm").encoding = "multipart/form-data"; 
document.getElementById("uploadForm").submit(); 
} 
function ResetFile(file) { 
var tmpForm = document.createElement('form'); 
file.parentNode.insertBefore(tmpForm, file); 
tmpForm.appendChild(file); 
tmpForm.reset(); 
tmpForm.removeNode(false); 
} 
</script> 
</head> 
<body> 
<form id="uploadForm" name="uploadForm" action="Upload.ashx" method="post" target="hidIframe" enctype="multipart/form-data"> 
<table cellpadding='0' cellspacing='0' style="width:100%;height:100%;border-collapse:collapse;" border="0" > 
<tr> 
<td> 
<input id="txtFile" name="txtFile" type="file" style="border:solid 1px Gray;" /> 
<iframe name="hidIframe" id="hidIframe" style="display:none;" ></iframe> 
</td> 
</tr> 
<tr> 
<td> 
<input type="button" id="btnImportOK" value="Upload" onclick="UploadFile();" /> 
<input type="button" id="btnImportCancel" onclick="ResetFile(document.getElementById('txtFile'))" value="Reset"/> 
</td> 
</tr> 
</table> 
</form> 
</body> 
</html>

 
处理文件上传的c#
if (context.Request.Files.Count > 0) 
{ 
HttpPostedFile file = context.Request.Files[0]; 
if (file.ContentLength > 0) 
{ 
string title = string.Empty; 
title = DateTime.Now.ToString("yyyyMMddHHmmss") + "_" + Path.GetFileName(file.FileName); 
string path = "./Upload/" + title; 
path = System.Web.HttpContext.Current.Server.MapPath(path); 
file.SaveAs(path); 
context.Response.Write("<script>window.parent.FinishUpload('" + HttpUtility.UrlEncode(path) + "');</script>"); 
} 
} 
else 
{ 
context.Response.Write("<script>window.parent.FinishUpload('');</script>"); 
}

  做到无刷新,基本原理就是:通过表单提交到iframe里,从而使刷新发生在iframe里。form设置action指向处理上传的文件,target指向iframe。上传操作的结果可以返回到iframe里,调用父对象的FinishUpload方法显示是否上传成功。所以在AJAX未流行时,常用这种方法来伪装未刷新的效果,现在仍然可以使用。
要注意的是:
enctype="multipart/form-data"不可少,enctype默认编码是“application/x-www-form-urlencoded”,设置enctype="multipart/form-data",用于二进制方式上传文件。
为防止文件名乱码,防止乱七八糟字符URL传递中出现问题,返回文件名到前台时进行HttpUtility.UrlEncode,在前台JS中取文件名时进行decodeURIComponent。
重置文件选择框时,要把文件选择框临时插入到临时表单,通过表单的reset方法重置。
顺便贴上解析上传的csv文件的code
解析csv文件
private DataTable ImportDataTable(string filepath) 
{ 
DataTable mydt = new DataTable("myTableName"); 
mydt.Columns.Add("Data ID", System.Type.GetType("System.String")); 
mydt.Columns.Add("Field Name", System.Type.GetType("System.String")); 
mydt.Columns.Add("New Value", System.Type.GetType("System.String")); 
DataRow mydr; 
using (System.IO.StreamReader mysr = new System.IO.StreamReader(filepath)) 
{ 
int data; 
char current; 
StringBuilder text = new StringBuilder(); 
IDictionary<int, List<string>> results = new Dictionary<int, List<string>>(); 
bool isInYinHao = false; ; 
int lineId = 1; 
int index = 0; 
while (true) 
{ 
data = mysr.Read(); 
if (data != -1) 
{ 
current = (char)data; 
if (current == '"') 
{ 
if (isInYinHao) 
{ 
isInYinHao = false; 
} 
else 
{ 
if (index > 0) 
{ 
text.Append(current); 
} 
isInYinHao = true; 
} 
} 
else if (current == ',') 
{ 
if (isInYinHao) 
{ 
text.Append(current); 
} 
else 
{ 
SaveResult(results, lineId, text); 
index = 0; 
continue; 
} 
} 
else if (current == '\r') 
{ 
if (isInYinHao) 
{ 
text.Append(current); 
} 
} 
else if (current == '\n') 
{ 
if (isInYinHao) 
{ 
text.Append(current); 
} 
else 
{ 
SaveResult(results, lineId, text); 
index = 0; 
lineId++; 
continue; 
} 
} 
else if (current == '\0') 
{ 
} 
else 
{ 
text.Append(current); 
} 
index++; 
} 
else 
{ 
//Read to file end. 
SaveResult(results, lineId, text); 
break; 
} 
} 
foreach (int id in results.Keys) 
{ 
mydr = mydt.NewRow(); 
for (int i = 0; i < results[id].Count; i++) 
{ 
if (i > 2) 
{ 
break; 
} 
mydr[i] = results[id][i]; 
} 
mydt.Rows.Add(mydr); 
} 
} 
return mydt; 
} 
private void SaveResult(IDictionary<int, List<string>> results, int lineId, StringBuilder text) 
{ 
if (!results.ContainsKey(lineId)) 
{ 
results.Add(lineId, new List<string>()); 
} 
results[lineId].Add(text.ToString()); 
text.Remove(0, text.Length); 
}

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