文章来源：http://www.2cto.com/kf/201205/132249.html
首先，将以下js代码放入页面这里我判断的是只能上传xls格式的文件，可以根据自己的需求修改js中的checkExcel方法
</pre><pre name="code" class="javascript"><script type="text/javascript">
var __FILE_INDEX = 0; //文件标识
var __LOADING_TIP_DIV = null;
var __ICON_PATH = "<%=Request.ApplicationPath%>/Images";
/**
* 对选择的文件进行格式校验,只能选择xls格式的文件
*/
function checkFile(fileObj) {
var objSpan = document.getElementById("span_" + fileObj.id);
if (!checkExcel(fileObj.value)) {
objSpan.innerHTML = "<img title='错误' src='" + __ICON_PATH + "/check_error.png' border='0'></img><font style='color:red;font-size:12px'>只能导入xls格式文件！</font>"
fileObj.errFlag = true;
} else {
objSpan.innerHTML = "<img title='正确' src='" + __ICON_PATH + "/check_right.png' border='0'></img>"
fileObj.errFlag = false;
}
if (fileObj.value != "" && fileObj.noDelete != "true") {
document.getElementById("del_" + fileObj.id).innerHTML = "<span title='删除文件' οnclick='deleteFile(\"" + fileObj.id + "\")' style='font-size:12px;color: #4684b2;cursor:pointer;border-bottom:1px solid #4684b2'>删除</span>";
}
}
/**
* 删除选择的文件 www.2cto.com
*/
function deleteFile(fileId) {
var trNode = document.getElementById("tr_" + fileId);
var trParent = trNode.parentNode;
trParent.removeChild(trNode);
}
/**
* excel校验函数
*/
function checkExcel(filePath) {
var subfix = filePath.substring(filePath.lastIndexOf(".") + 1);
if (subfix != "xls") {
return false;
}
return true;
}
/**
* 文件上传时的校验逻辑
*/
function excelUpload() {
var fileCount = 0;
var files = document.getElementsByTagName("INPUT");
for (var i = 0; i < files.length; i++) {
if (files[i].type.toLowerCase != 'file') continue;
if (files[i].errFlag) {
alert("导入的文件只能是xls格式，请重新选择.");
files[i].focus();
return;
}
if (files[i].value != "")
fileCount++;
}
if (fileCount < 1) {
alert("请先选择要上传的数据文件!");
return;
}
document.getElementById("uploadExcelForm").submit();
}
/**
* 添加文件
*/
function addFile() {
++__FILE_INDEX;
var fileId = "file" + __FILE_INDEX;
var uploadTable = document.getElementById("tableUploadFile")
var trElement = uploadTable.insertRow(-1);
trElement.id = "tr_" + fileId;
var tdElement = trElement.insertCell(-1);
tdElement.id = "td_" + fileId;
tdElement.innerHTML = "<input type='file' name='" + fileId + "' id='" + fileId + "' size='30' style='padding-left:5px;width:300px;cursor:pointer;' >"
+ "<span id='span_" + fileId + "'></span>"
+ "<span id='del_" + fileId + "'></span>";
}
</script>
接下来是后台代码：
[csharp] //保存上传文件
try
{
for (int i = 0; i < Request.Files.Count; i++)
{
if (Request.Files["file" + i] != null)
{
HttpPostedFile filePost = Request.Files["file" + i];
string filename = filePost.FileName;
Random rd = new Random();
filename = filename.Substring(filename.LastIndexOf('\\') + 1);
string savePath = Server.MapPath("UpLoadFile/" + rd.Next() + filename);
filePost.SaveAs(savePath);
UpLoadFile upLoadfile = new UpLoadFile();
upLoadfile.FileObj = mubiao.Obj_Id;
upLoadfile.FileAddr = savePath;
upLoadfile.FileUpLoadDate = DateTime.Now;
new UpLoadFileBLL().InsertUpLoadFile(upLoadfile);
}
}
}
catch (Exception)
{
PageMessageBoxShow("文件上传失败！");
}