在网络编程过程中需要向服务器上传文件。
Multipart/form-data是上传文件的一种方式。
/// <summary>
/// 上传工程文件
/// </summary>
/// <returns></returns>
public async Task<HttpResponseMessage> UploadProjectFile()
{
ProjectFile postData = new ProjectFile();
IEnumerable<string> stringValues;
//获取请求头文件相关参数
Request.Headers.TryGetValues("token", out stringValues);
postData.token = stringValues.FirstOrDefault(); Request.Headers.TryGetValues("uid", out stringValues);
postData.uid = int.Parse(stringValues.FirstOrDefault()); Request.Headers.TryGetValues("project_id", out stringValues);
postData.project_id = int.Parse(stringValues.FirstOrDefault()); Request.Headers.TryGetValues("md5", out stringValues);
postData.md5 = stringValues.FirstOrDefault(); Request.Headers.TryGetValues("file_name", out stringValues);
postData.file_name = stringValues.FirstOrDefault();
//验证Token
var result = CheckToken(postData.token);
if (!result)
{
return CreateResponseError(, "请求拒绝");
}
//获取文件名，这里的文件名必须带扩展名
string fileName = postData.file_name; int projectId = postData.project_id;
//获取应用程序的当前工作目录
string rootPath = HostingEnvironment.MapPath("~/");
//通过Path类的Combine方法可以合并路径。获取当前工程文件夹地址
string directoryPath = Path.Combine(rootPath, "BgerProject", projectId.ToString());
//创建目录时如果目录已存在，则不会重新创建目录，且不会报错。创建目录时会自动创建路径中各级不存在的目录。
Directory.CreateDirectory(directoryPath);
//获取当前工程文件地址
string filePath = Path.Combine(directoryPath, fileName);
if (Request.Content.IsMimeMultipartContent())
{
Dictionary<string, string> dic = new Dictionary<string, string>();
var provider = new MultipartFormDataMemoryStreamProvider(); await Request.Content.ReadAsMultipartAsync(provider);
foreach (var item in provider.FileContents)
{
//Trace.WriteLine(item.Headers.ContentDisposition.FileName);//获取上传文件实际的文件名
//Trace.WriteLine("Server file path: " + item.LocalFileName);//获取上传文件在服务上默认的文件名
var stream = await item.ReadAsStreamAsync();
if (Path.GetExtension(item.Headers.ContentDisposition.FileName.Replace("\"", "")) == ".mp4")
{
//通过正则表达式判断是视频还是音频
Regex regex = new Regex("voice", RegexOptions.Compiled);
Match m = regex.Match(item.Headers.ContentDisposition.Name.ToLower());
if (m.Success)
{
//音频直接保存处理 //判断是否已存在该音频
if (!File.Exists(filePath))
{
using (StreamWriter sw = new StreamWriter(filePath))
{
stream.CopyTo(sw.BaseStream);
sw.Flush();
}
}
}
else
{
//视频进行压缩处理
//保存原片(如果路径不存在，创建路径) using (StreamWriter sw = new StreamWriter(filePath))
{
stream.CopyTo(sw.BaseStream);
sw.Flush();
}
//压缩并保存上传的视频
//压缩后的存放路径（如果路径不存在，创建路径）
////判断是否已存在该视频
//if (!File.Exists(filePath))
//{
// //压缩保存视频
// if (!FFMPEGHelper.CreateNewVideo(originalFilePath, filePath))
// {
// continue;
// };
//}
}
}
else
{
//保存原片(如果路径不存在，创建路径) using (StreamWriter sw = new StreamWriter(filePath))
{
stream.CopyTo(sw.BaseStream);
sw.Flush();
}
//压缩并保存上传的图片
//压缩后的存放路径（如果路径不存在，创建路径） ////判断是否已存在该图片
//if (!File.Exists(filePath))
//{
// var pxLimit = 481;
// //判断是否需要压缩
// System.Drawing.Image iSource = System.Drawing.Image.FromFile(originalFilePath);
// if (iSource.Width <= pxLimit || iSource.Height <= pxLimit)
// {
// //无需压缩
// System.IO.File.Copy(originalFilePath, filePath);
// }
// else
// {
// var min = Math.Min((int)iSource.Width, (int)iSource.Height);
// if (min > pxLimit)
// {
// //缩放倍率
// var rate = (double)pxLimit / min;
// var width = (int)Math.Ceiling(rate * (double)iSource.Width);
// var height = (int)Math.Ceiling(rate * (double)iSource.Height); // //压缩保存图片
// if (!ImageHelper.GetPicThumbnail(originalFilePath, filePath, height, width, 100))
// {
// continue;
// };
// }
// }
//}
}
}
return CreateResponse("请求成功"); }
return CreateResponseError(,"缺少MIME内容"); }
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.IO;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading;
using System.Threading.Tasks; namespace BgerServer.Models
{
/// <summary>
/// 与MultipartFormDataStreamProvider对应，但不将文件直接存入指定位置，而是需要自己指定数据流如何保存
/// </summary>
public class MultipartFormDataMemoryStreamProvider : MultipartStreamProvider
{
private NameValueCollection _formData = new NameValueCollection();
private Collection<bool> _isFormData = new Collection<bool>();
/// <summary>
/// 获取文件对应的HttpContent集合,文件如何读取由实际使用方确定，可以ReadAsByteArrayAsync，也可以ReadAsStreamAsync
/// </summary>
public Collection<HttpContent> FileContents
{
get
{
if (this._isFormData.Count != this.Contents.Count)//两者总数不一致，认为未执行过必须的Request.Content.ReadAsMultipartAsync(provider)方法
{
throw new InvalidOperationException("System.Net.Http.HttpContentMultipartExtensions.ReadAsMultipartAsync must be called first!");
}
return new Collection<HttpContent>(this.Contents.Where((ct, idx) => !this._isFormData[idx]).ToList());
}
}
/// <summary>Gets a <see cref="T:System.Collections.Specialized.NameValueCollection" /> of form data passed as part of the multipart form data.</summary>
/// <returns>The <see cref="T:System.Collections.Specialized.NameValueCollection" /> of form data.</returns>
public NameValueCollection FormData
{
get
{
return this._formData;
}
}
public override async Task ExecutePostProcessingAsync()
{
for (var i = ; i < this.Contents.Count; i++)
{
if (!this._isFormData[i])//非文件
{
continue;
}
var formContent = this.Contents[i];
ContentDispositionHeaderValue contentDisposition = formContent.Headers.ContentDisposition;
string formFieldName = UnquoteToken(contentDisposition.Name) ?? string.Empty;
string formFieldValue = await formContent.ReadAsStringAsync();
this.FormData.Add(formFieldName, formFieldValue);
}
}
public override Stream GetStream(HttpContent parent, HttpContentHeaders headers)
{
if (parent == null)
{
throw new ArgumentNullException("parent");
}
if (headers == null)
{
throw new ArgumentNullException("headers");
}
ContentDispositionHeaderValue contentDisposition = headers.ContentDisposition;
if (contentDisposition == null)
{
throw new InvalidOperationException("Content-Disposition is null");
}
this._isFormData.Add(string.IsNullOrEmpty(contentDisposition.FileName));
return new MemoryStream();
}
/// <summary>
/// 复制自 System.Net.Http.FormattingUtilities 下同名方法，因为该类为internal，不能在其它命名空间下被调用
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
private static string UnquoteToken(string token)
{
if (string.IsNullOrWhiteSpace(token))
{
return token;
}
if (token.StartsWith("\"", StringComparison.Ordinal) && token.EndsWith("\"", StringComparison.Ordinal) && token.Length > )
{
return token.Substring(, token.Length - );
}
return token;
}
}
}