前端：
<!DOCTYPE html><html><head> ???<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> ???<title></title> ???<meta charset="utf-8" /> ???<script type="text/javascript"> ???????$.support.cors = true; ???????var ApiUrl = "http://localhost:12745/"; ???????$(function () { ???????????$("#upload").click(function () { ???????????????$("#imgWait").show(); ???????????????var formData = new FormData(); ???????????????formData.append("myfile", document.getElementById("file1").files[0]); ???????????????$.ajax({ ???????????????????url: ApiUrl + "api/FileManage/UploadFile", ???????????????????type: "POST", ???????????????????data: formData, ???????????????????/** ???????????????????*必须false才会自动加上正确的Content-Type ???????????????????*/ ???????????????????contentType: false, ???????????????????/** ???????????????????* 必须false才会避开jQuery对 formdata 的默认处理 ???????????????????* XMLHttpRequest会对 formdata 进行正确的处理 ???????????????????*/ ???????????????????processData: false, ???????????????????success: function (data) { ???????????????????????if (data.status == "true") { ???????????????????????????alert("上传成功！"); ???????????????????????} ???????????????????????if (data.status == "error") { ???????????????????????????alert(data.msg); ???????????????????????} ???????????????????????$("#imgWait").hide(); ???????????????????}, ???????????????????error: function () { ???????????????????????alert("上传失败！"); ???????????????????????$("#imgWait").hide(); ???????????????????} ???????????????}); ???????????}); ???????}); ???</script></head><body> ???选择文件:<input type="file" id="file1" /><br /> ???<input type="button" id="upload" value="上传" /> ???<img src="wait.gif" style="display:none" id="imgWait" /></body></html>
后端：
/// <summary> ???????/// 文件上传 ???????/// </summary> ???????/// <returns></returns> ???????[HttpPost] ???????public HttpResponseMessage UploadFile() ???????{ ???????????????????????HttpResponseMessage result = null; ???????????var httpRequest = System.Web.HttpContext.Current.Request; ???????????if (httpRequest.Files.Count > 0) ???????????{ ???????????????try ???????????????{ ???????????????????string url = string.Empty; ???????????????????foreach (string file in httpRequest.Files) ???????????????????{ ???????????????????????var postedFile = httpRequest.Files[file]; ???????????????????????var filePath = System.Web.HttpContext.Current.Server.MapPath("~/Files/"); ???????????????????????if (!Directory.Exists(filePath)) ???????????????????????{ ???????????????????????????Directory.CreateDirectory(filePath); ???????????????????????} ???????????????????????postedFile.SaveAs(filePath + postedFile.FileName); ???????????????????????url += "Files/" + postedFile.FileName + ","; ???????????????????} ???????????????????result = Request.CreateResponse(HttpStatusCode.OK, url.Substring(0, url.Length - 1)); ???????????????} ???????????????catch (Exception ex) ???????????????{ ???????????????????result = Request.CreateResponse(HttpStatusCode.OK, "error:" + ex.Message); ???????????????} ???????????} ???????????else ???????????{ ???????????????result = Request.CreateResponse(HttpStatusCode.OK, "0"); ???????????} ???????????return result; ???????} ???????/// <summary> ???????/// 根据ID 下载文件 ???????/// </summary> ???????/// <returns></returns> ???????[HttpGet] ???????public HttpResponseMessage DownLoadFile(Guid id) ???????{ ???????????try ???????????{ ???????????????DataTable dt = null; //BLL.Menu.GetModelByID(id); ???????????????if (dt.Rows.Count>0) ???????????????{ ???????????????????byte[] bytes = dt.Rows[0]["Icon"] as byte[]; ???????????????????if (bytes.Length>0) ???????????????????{ ???????????????????????//InputStream input = new ByteArrayInputStream(bytes); ???????????????????} ???????????????} ???????????????var FilePath = @"C:\Users\Jone-pc\Desktop\QQ图片20170705090821.png";//System.Web.Hosting.HostingEnvironment.MapPath(@"C:\Users\Jone-pc\Desktop\QQ图片20170705090821.png"); ???????????????var stream = new FileStream(FilePath, FileMode.Open); ???????????????HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK); ???????????????response.Content = new StreamContent(stream); ???????????????response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream"); ???????????????response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment") ???????????????{ ???????????????????FileName = "Wep Api Demo File.jpg" ???????????????}; ???????????????return response; ???????????} ???????????catch (Exception ex) ???????????{ ???????????????return new HttpResponseMessage(HttpStatusCode.NoContent); ???????????} ???????} ???????/// <summary> ???????/// 将文件上传到指定路径中保存 ???????/// </summary> ???????/// <returns>上传文件结果信息</returns> ???????[System.Web.Http.HttpPost] ???????//[ValidateInput(false)] ???????public HttpResponseMessage PostExcelData() ???????{ ???????????string info = string.Empty; ???????????try ???????????{ ???????????????//获取客户端上传的文件集合 ???????????????HttpFileCollection files = System.Web.HttpContext.Current.Request.Files; ???????????????//判断是否存在文件 ???????????????if (files.Count > 0) ???????????????{ ???????????????????//获取文件集合中的第一个文件(每次只上传一个文件) ???????????????????HttpPostedFile file = files[0]; ???????????????????//定义文件存放的目标路径 ???????????????????string targetDir = System.Web.HttpContext.Current.Server.MapPath("~/FileUpLoad/Product"); ???????????????????//创建目标路径 ???????????????????//ZFiles.CreateDirectory(targetDir); ???????????????????if (!System.IO.Directory.Exists(targetDir)) ???????????????????{ ???????????????????????Directory.CreateDirectory(targetDir); ???????????????????} ???????????????????string fullDir = System.IO.Path.Combine(targetDir + file.FileName); ???????????????????//组合成文件的完整路径 ???????????????????//string path = System.IO.Path.Combine(targetDir, System.IO.Path.GetFileName(file.FileName)); ???????????????????//保存上传的文件到指定路径中 ???????????????????file.SaveAs(fullDir); ???????????????????info = "上传成功"; ???????????????} ???????????????else ???????????????{ ???????????????????info = "上传失败"; ???????????????} ???????????} ???????????catch ???????????{ ???????????????info = "上传失败"; ???????????} ???????????return new HttpResponseMessage { Content = new StringContent(info, System.Text.Encoding.UTF8, "text/html") }; ???????}
文件上传
原文地址：https://www.cnblogs.com/liuqiyun/p/8624388.html