.Net之使用Jquery Ajax通过FormData对象异步提交图片文件到服务端保存并返回保存的图片路径

<div>头像</div>
<div class="tuxiang-up" id="headPortrait" style="background-image:url(/Content/ExSys/images/ktoux.jpg))">
<input type="file" onchange="uploadImage(this)">
<!--点击上传按钮后，图片缩略图以上级背景图片显示--> 
</div>

<script type="text/javascript">
//用户头像修改
function uploadImage(obj) {
var formData = new FormData();//创建FormData对象，以键值对的方式拼接form表单数据（multipart/form-data，图片媒体文件）
//获取input中的文件列表信息
 var files = $(obj).prop("files");
//拼接图片文件流信息
console.log(files[0]);
formData.append("file", files[0]);
$.ajax({
url: "/FileUpload/FileLoad/",
type: ‘POST‘,
data: formData,
async: false,
dataType: "json",
// 告诉jQuery不要去处理发送的数据
processData: false,
// 告诉jQuery不要去设置Content-Type请求头
contentType: false,
beforeSend: function () {
console.log("正在进行，请稍候");
},
success: function (data) {
if (data.isSuccess) {
console.log(data.path);
console.log("图片上传成功");
//动态赋值
$("#headPortrait").css("background-image", "url(" + data.path + ")");
} 
else {
console.log("网络异常，请稍后再试");
}
},
 error: function (data) {
console.log("error2");
}
});
}
</script>    　

  1public class FileUploadController : Controller
  2{
  3/// <summary>
  4 /// 对验证和处理 HTML 窗体中的输入数据所需的信息进行封装，如FromData拼接而成的文件
  5 /// </summary>
  6 /// <param name="context">FemContext对验证和处理html窗体中输入的数据进行封装</param>
  7 /// <returns></returns>
  8 [HttpPost]
  9 public ActionResult FileLoad(FormContext context)
 10  {
 11 HttpPostedFileBase httpPostedFileBase = Request.Files[0];//获取二进制图片文件流
 12 if (httpPostedFileBase != null)
 13 {
 14 try
 15 {
 16 ControllerContext.HttpContext.Request.ContentEncoding = Encoding.GetEncoding("UTF-8");
 17 ControllerContext.HttpContext.Response.Charset = "UTF-8";
 18 
 19 string fileName = Path.GetFileName(httpPostedFileBase.FileName);//原始文件名称
 20 string fileExtension = Path.GetExtension(fileName);//文件扩展名
 21 
 22 byte[] fileData = ReadFileBytes(httpPostedFileBase);//文件流转化为二进制字节
 23 
 24 string result = SaveFile(fileExtension, fileData);//文件保存
 25 if (string.IsNullOrEmpty(result))
 26 {
 27 return Json(new { isSuccess = false, path = "",errorMsg= "上传文件失败"});
 28 }
 29 
 30 return Json(new { isSuccess = true, path = result });
 31 }
 32 catch (Exception ex)
 33 {
 34 return Json(new { isSuccess = false, path = "" });
 35 }
 36 }
 37 else
 38 {
 39 return Json(new { isSuccess = false, path = "" });
 40 }
 41 }
 42 
 43 
 44 /// <summary>
 45 /// 将文件流转化为二进制字节
 46 /// </summary>
 47 /// <param name="fileData">图片文件流</param>
 48 /// <returns></returns>
 49 private byte[] ReadFileBytes(HttpPostedFileBase fileData)
 50 {
 51 byte[] data;
 52 using (Stream inputStream = fileData.InputStream)
 53 {
 54 MemoryStream memoryStream = inputStream as MemoryStream;
 55 if (memoryStream == null)
 56 {
 57 memoryStream = new MemoryStream();
 58 inputStream.CopyTo(memoryStream);
 59 }
 60 data = memoryStream.ToArray();
 61 }
 62 return data;
 63 }
 64 
 65 /// <summary>
 66 /// 保存文件
 67 /// </summary>
 68 /// <param name="fileExtension">文件扩展名</param>
 69 /// <param name="fileData">图片二进制文件信息</param>
 70 /// <returns></returns>
 71 private string SaveFile(string fileExtension, byte[] fileData)
 72 {
 73 string result;
 74 try
 75 {
 76 
 77 string saveName = Guid.NewGuid().ToString()+ fileExtension; //保存文件名称
 78 
 79 // 文件上传后的保存路径
 80 string basePath = "UploadFile";
 81 string saveDir = DateTime.Now.ToString("yyyy-MM-dd");
 82 string savePath = System.IO.Path.Combine(saveDir, saveName);
 83 
 84 string serverDir = System.IO.Path.Combine(Server.MapPath("~/"), basePath, saveDir);
 85 if (!System.IO.Directory.Exists(serverDir))
 86 {
 87 System.IO.Directory.CreateDirectory(serverDir);
 88 }
 89 string fileNme = System.IO.Path.Combine(serverDir, saveName);//保存文件完整路径
 90 System.IO.File.WriteAllBytes(fileNme, fileData);//WriteAllBytes创建一个新的文件，按照对应的文件流写入，假如已存在则覆盖
 91 //返回完整的图片保存地址
 92 result="/"+basePath + "/" + saveDir + "/" + saveName;
 93 }
 94 catch (Exception)
 95 {
 96 result = "发生错误";
 97 }
 98 return result;
100 }
101 }