基础知识，可由此衍生。原文：http://uniapple.net/blog/?p=2050
In this post, I will show you how to upload a file using Ajax (Asynchronous JavaScript and XML) and receive the binary data in Asp.net C#. And it is ultra simple!
<input id="bannerImage" name="bannerImage" type="file"><input onclick="javascript:uploadfile()" type="button" value="upload">
function uploadfile(){
var bannerImage = $("#bannerImage").val();
if (bannerImage) {
var file = document.getElementById(‘bannerImage‘).files[0];
var formData = new FormData();
formData.append(file.name, file);
var xhr = new XMLHttpRequest();
var url = "/Category/UpdateBannerImage";
xhr.open(‘POST‘, url, true);
xhr.onload = function (e) {
var response = $.parseJSON(e.target.response);
console.log(response.fileName);
};
xhr.send(formData); // multipart/form-data
}
}(Sending Binary Data)
public JsonResult UpdateBannerImage()
{
HttpPostedFileBase bannerImage = Request.Files[0] as HttpPostedFileBase;
if (bannerImage != null && bannerImage.ContentLength > 0)
{
var fileName = Path.GetFileName(bannerImage.FileName);
fileName = Regex.Replace(fileName, @"\s|\$|\#\%", "");
var path = Path.Combine(Server.MapPath("~/images/category_banners"), fileName);
bannerImage.SaveAs(path);
return Json(new { success = false ,error = false, message = "Image has been updated successfully", fileName = fileName });
}
else
{
return Json(new { success = true, error = "File is empty" });
}
}Uploading File using Ajax and receiving binary data in Asp.net (C#)[转]
原文：http://www.cnblogs.com/walkerwang/p/3551647.html