ASP.NET 服务端接收Multipart/form-data文件

2018-06-22 07:51:13来源：未知阅读 ()

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。

  1        /// <summary>
  2        /// 上传工程文件
  3        /// </summary>
  4        /// <returns></returns>
  5         public async Task<HttpResponseMessage> UploadProjectFile()
  6         {
  7                 ProjectFile postData = new ProjectFile();
  8                 IEnumerable<string> stringValues;
  9                 //获取请求头文件相关参数
 10                 Request.Headers.TryGetValues("token", out stringValues);
 11                 postData.token = stringValues.FirstOrDefault();
 12 
 13                 Request.Headers.TryGetValues("uid", out stringValues);
 14                 postData.uid = int.Parse(stringValues.FirstOrDefault());
 15 
 16                 Request.Headers.TryGetValues("project_id", out stringValues);
 17                 postData.project_id = int.Parse(stringValues.FirstOrDefault());
 18 
 19                 Request.Headers.TryGetValues("md5", out stringValues);
 20                 postData.md5 = stringValues.FirstOrDefault();
 21 
 22                 Request.Headers.TryGetValues("file_name", out stringValues);
 23                 postData.file_name = stringValues.FirstOrDefault();
 24                //验证Token
 25                 var result = CheckToken(postData.token);
 26                 if (!result)
 27                 {
 28                     return CreateResponseError(401, "请求拒绝");
 29                 }
 30                 //获取文件名，这里的文件名必须带扩展名
 31                 string fileName = postData.file_name;
 32                 
 33                 int projectId = postData.project_id;
 34                 //获取应用程序的当前工作目录
 35                 string rootPath = HostingEnvironment.MapPath("~/");
 36                 //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
 37                 string directoryPath = Path.Combine(rootPath, "BgerProject", projectId.ToString());
 38                 //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。
 39                 Directory.CreateDirectory(directoryPath);
 40                 //获取当前工程文件地址
 41                 string filePath = Path.Combine(directoryPath, fileName);
 42                 if (Request.Content.IsMimeMultipartContent())
 43                 {
 44                     Dictionary<string, string> dic = new Dictionary<string, string>();
 45                     var provider = new MultipartFormDataMemoryStreamProvider();
 46                     
 47                     await Request.Content.ReadAsMultipartAsync(provider);
 48                     foreach (var item in provider.FileContents)
 49                     {
 50                         //Trace.WriteLine(item.Headers.ContentDisposition.FileName);//获取上传文件实际的文件名  
 51                         //Trace.WriteLine("Server file path: " + item.LocalFileName);//获取上传文件在服务上默认的文件名  
 52                         var stream = await item.ReadAsStreamAsync();
 53                         if (Path.GetExtension(item.Headers.ContentDisposition.FileName.Replace("\"", "")) == ".mp4")
 54                         {
 55                             //通过正则表达式判断是视频还是音频
 56                             Regex regex = new Regex("voice", RegexOptions.Compiled);
 57                             Match m = regex.Match(item.Headers.ContentDisposition.Name.ToLower());
 58                             if (m.Success)
 59                             {
 60                                 //音频直接保存处理
 61                                
 62                                 //判断是否已存在该音频
 63                                 if (!File.Exists(filePath))
 64                                 {
 65                                     using (StreamWriter sw = new StreamWriter(filePath))
 66                                     {
 67                                         stream.CopyTo(sw.BaseStream);
 68                                         sw.Flush();
 69                                     }
 70                                 }
 71                             }
 72                             else
 73                             {
 74                                 //视频进行压缩处理
 75                                 //保存原片(如果路径不存在，创建路径)
 76                                 
 77                                 using (StreamWriter sw = new StreamWriter(filePath))
 78                                 {
 79                                     stream.CopyTo(sw.BaseStream);
 80                                     sw.Flush();
 81                                 }
 82                                 //压缩并保存上传的视频
 83                                 //压缩后的存放路径（如果路径不存在，创建路径）
 84                                 ////判断是否已存在该视频
 85                                 //if (!File.Exists(filePath))
 86                                 //{
 87                                 //    //压缩保存视频
 88                                 //    if (!FFMPEGHelper.CreateNewVideo(originalFilePath, filePath))
 89                                 //    {
 90                                 //        continue;
 91                                 //    };
 92                                 //}
 93                             }
 94                         }
 95                         else
 96                         {
 97                             //保存原片(如果路径不存在，创建路径)
 98                            
 99                             using (StreamWriter sw = new StreamWriter(filePath))
100                             {
101                                 stream.CopyTo(sw.BaseStream);
102                                 sw.Flush();
103                             }
104                             //压缩并保存上传的图片
105                             //压缩后的存放路径（如果路径不存在，创建路径）
106                            
107                             ////判断是否已存在该图片
108                             //if (!File.Exists(filePath))
109                             //{
110                             //    var pxLimit = 481;
111                             //    //判断是否需要压缩
112                             //    System.Drawing.Image iSource = System.Drawing.Image.FromFile(originalFilePath);
113                             //    if (iSource.Width <= pxLimit || iSource.Height <= pxLimit)
114                             //    {
115                             //        //无需压缩
116                             //        System.IO.File.Copy(originalFilePath, filePath);
117                             //    }
118                             //    else
119                             //    {
120                             //        var min = Math.Min((int)iSource.Width, (int)iSource.Height);
121                             //        if (min > pxLimit)
122                             //        {
123                             //            //缩放倍率
124                             //            var rate = (double)pxLimit / min;
125                             //            var width = (int)Math.Ceiling(rate * (double)iSource.Width);
126                             //            var height = (int)Math.Ceiling(rate * (double)iSource.Height);
127 
128                             //            //压缩保存图片
129                             //            if (!ImageHelper.GetPicThumbnail(originalFilePath, filePath, height, width, 100))
130                             //            {
131                             //                continue;
132                             //            };
133                             //        }
134                             //    }
135                             //}
136                         }
137                     }
138                     return CreateResponse("请求成功");
139                     
140                 }
141                 return CreateResponseError(202,"缺少MIME内容");
142             
143         }

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Web;
 5 using System.Collections.ObjectModel;
 6 using System.Collections.Specialized;
 7 using System.IO;
 8 using System.Net.Http;
 9 using System.Net.Http.Headers;
10 using System.Threading;
11 using System.Threading.Tasks;
12 
13 namespace BgerServer.Models
14 {
15     /// <summary>  
16     /// 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  
17     /// </summary>  
18     public class MultipartFormDataMemoryStreamProvider : MultipartStreamProvider
19     {
20         private NameValueCollection _formData = new NameValueCollection();
21         private Collection<bool> _isFormData = new Collection<bool>();
22         /// <summary>  
23         /// 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  
24         /// </summary>  
25         public Collection<HttpContent> FileContents
26         {
27             get
28             {
29                 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  
30                 {
31                     throw new InvalidOperationException("System.Net.Http.HttpContentMultipartExtensions.ReadAsMultipartAsync must be called first!");
32                 }
33                 return new Collection<HttpContent>(this.Contents.Where((ct, idx) => !this._isFormData[idx]).ToList());
34             }
35         }
36         /// <summary>Gets a <see cref="T:System.Collections.Specialized.NameValueCollection" /> of form data passed as part of the multipart form data.</summary>  
37         /// <returns>The <see cref="T:System.Collections.Specialized.NameValueCollection" /> of form data.</returns>  
38         public NameValueCollection FormData
39         {
40             get
41             {
42                 return this._formData;
43             }
44         }
45         public override async Task ExecutePostProcessingAsync()
46         {
47             for (var i = 0; i < this.Contents.Count; i++)
48             {
49                 if (!this._isFormData[i])//非文件  
50                 {
51                     continue;
52                 }
53                 var formContent = this.Contents[i];
54                 ContentDispositionHeaderValue contentDisposition = formContent.Headers.ContentDisposition;
55                 string formFieldName = UnquoteToken(contentDisposition.Name) ?? string.Empty;
56                 string formFieldValue = await formContent.ReadAsStringAsync();
57                 this.FormData.Add(formFieldName, formFieldValue);
58             }
59         }
60         public override Stream GetStream(HttpContent parent, HttpContentHeaders headers)
61         {
62             if (parent == null)
63             {
64                 throw new ArgumentNullException("parent");
65             }
66             if (headers == null)
67             {
68                 throw new ArgumentNullException("headers");
69             }
70             ContentDispositionHeaderValue contentDisposition = headers.ContentDisposition;
71             if (contentDisposition == null)
72             {
73                 throw new InvalidOperationException("Content-Disposition is null");
74             }
75             this._isFormData.Add(string.IsNullOrEmpty(contentDisposition.FileName));
76             return new MemoryStream();
77         }
78         /// <summary>  
79         /// 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  
80         /// </summary>  
81         /// <param name="token"></param>  
82         /// <returns></returns>  
83         private static string UnquoteToken(string token)
84         {
85             if (string.IsNullOrWhiteSpace(token))
86             {
87                 return token;
88             }
89             if (token.StartsWith("\"", StringComparison.Ordinal) && token.EndsWith("\"", StringComparison.Ordinal) && token.Length > 1)
90             {
91                 return token.Substring(1, token.Length - 2);
92             }
93             return token;
94         }
95     }
96 }