C#获取文件的Content-Type(MIME Type)的三种方法

Bertha 。 2024-04-18 04:28 54阅读 0赞

### 什么是ContentType? ###

我们知道浏览器可以处理各种各样的内容，比如：HTML、XML、JPG、Flash等等，那么浏览器是如何区分它们的呢？答案就是MIME Type，即资源的媒体类型。媒体类型通常是通过 HTTP 协议，由 Web 服务器告知浏览器的，更准确地说，是通过 Content-Type 来表示的，例如：

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> <code>Content-Type:text/html;</code> </td> 
 </tr> 
 </tbody> 
</table>

这里简单说一下什么是Content-Type，详细内容自行到网上搜索。

查看[完整的Http Content-Type对照表][Http Content-Type]

### C\#获取文件的ContentType的方法 ###

C\#获取文件的ContentType有三种方法，下面分别介绍。

第一种，使用MimeMapping

使用.NET提供的现有方法是最简单的，但是需要.NET Framework 4.5及以后的支持。MimeMapping在System.Web命名空间下。

<table> 
 <tbody> 
 <tr> 
 <td> 1 2 3 </td> 
 <td> <code>string</code> <code>fileName =&nbsp;</code><code>"nmtree.png"</code><code>;</code> <code>var</code> <code>contentType = MimeMapping.GetMimeMapping(fileName);</code> <code>Console.WriteLine(contentType);</code> </td> 
 </tr> 
 </tbody> 
</table>

第二种，通过注册表

本方法需要有访问注册表的权限。

<table> 
 <tbody> 
 <tr> 
 <td> 1 2 3 4 5 6 7 8 9 10 11 </td> 
 <td> <code>public</code> <code>static</code> <code>string</code> <code>GetMimeMapping(</code><code>string</code> <code>fileName)</code> <code>{ </code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>string</code> <code>mimeType =&nbsp;</code><code>"application/octet-stream"</code><code>;</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>string</code> <code>ext = Path.GetExtension(fileName).ToLower();</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>RegistryKey regKey = Registry.ClassesRoot.OpenSubKey(ext);</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>if</code> <code>(regKey !=&nbsp;</code><code>null</code> <code>&amp;&amp; regKey.GetValue(</code><code>"Content Type"</code><code>) !=&nbsp;</code><code>null</code><code>)</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>{ </code> <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>mimeType = regKey.GetValue(</code><code>"Content Type"</code><code>).ToString();</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>}</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>return</code> <code>mimeType;</code> <code>}</code> </td> 
 </tr> 
 </tbody> 
</table>

第三种，手动映射

这种方法在受到.NET版本和访问注册表权限时，是最佳解决方案，虽然代码看起来很多，不过下面的类直接拿走用就可以了。

public class FileContentType
 
 {
 
 private static IDictionary<string, string> _mappings = new Dictionary<string, string>(StringComparer.InvariantCultureIgnoreCase) {
 
 
 #region Big freaking list of mime types
 
 // combination of values from Windows 7 Registry and
 
 // from C:\Windows\System32\inetsrv\config\applicationHost.config
 
 // some added, including .7z and .dat
 
 {".323", "text/h323"},
 
 {".3g2", "video/3gpp2"},
 
 {".3gp", "video/3gpp"},
 
 {".3gp2", "video/3gpp2"},
 
 {".3gpp", "video/3gpp"},
 
 {".7z", "application/x-7z-compressed"},
 
 {".aa", "audio/audible"},
 
 {".AAC", "audio/aac"},
 
 {".aaf", "application/octet-stream"},
 
 {".aax", "audio/vnd.audible.aax"},
 
 {".ac3", "audio/ac3"},
 
 {".aca", "application/octet-stream"},
 
 {".accda", "application/msaccess.addin"},
 
 {".accdb", "application/msaccess"},
 
 {".accdc", "application/msaccess.cab"},
 
 {".accde", "application/msaccess"},
 
 {".accdr", "application/msaccess.runtime"},
 
 {".accdt", "application/msaccess"},
 
 {".accdw", "application/msaccess.webapplication"},
 
 {".accft", "application/msaccess.ftemplate"},
 
 {".acx", "application/internet-property-stream"},
 
 {".AddIn", "text/xml"},
 
 {".ade", "application/msaccess"},
 
 {".adobebridge", "application/x-bridge-url"},
 
 {".adp", "application/msaccess"},
 
 {".ADT", "audio/vnd.dlna.adts"},
 
 {".ADTS", "audio/aac"},
 
 {".afm", "application/octet-stream"},
 
 {".ai", "application/postscript"},
 
 {".aif", "audio/x-aiff"},
 
 {".aifc", "audio/aiff"},
 
 {".aiff", "audio/aiff"},
 
 {".air", "application/vnd.adobe.air-application-installer-package+zip"},
 
 {".amc", "application/x-mpeg"},
 
 {".application", "application/x-ms-application"},
 
 {".art", "image/x-jg"},
 
 {".asa", "application/xml"},
 
 {".asax", "application/xml"},
 
 {".ascx", "application/xml"},
 
 {".asd", "application/octet-stream"},
 
 {".asf", "video/x-ms-asf"},
 
 {".ashx", "application/xml"},
 
 {".asi", "application/octet-stream"},
 
 {".asm", "text/plain"},
 
 {".asmx", "application/xml"},
 
 {".aspx", "application/xml"},
 
 {".asr", "video/x-ms-asf"},
 
 {".asx", "video/x-ms-asf"},
 
 {".atom", "application/atom+xml"},
 
 {".au", "audio/basic"},
 
 {".avi", "video/x-msvideo"},
 
 {".axs", "application/olescript"},
 
 {".bas", "text/plain"},
 
 {".bcpio", "application/x-bcpio"},
 
 {".bin", "application/octet-stream"},
 
 {".bmp", "image/bmp"},
 
 {".c", "text/plain"},
 
 {".cab", "application/octet-stream"},
 
 {".caf", "audio/x-caf"},
 
 {".calx", "application/vnd.ms-office.calx"},
 
 {".cat", "application/vnd.ms-pki.seccat"},
 
 {".cc", "text/plain"},
 
 {".cd", "text/plain"},
 
 {".cdda", "audio/aiff"},
 
 {".cdf", "application/x-cdf"},
 
 {".cer", "application/x-x509-ca-cert"},
 
 {".chm", "application/octet-stream"},
 
 {".class", "application/x-java-applet"},
 
 {".clp", "application/x-msclip"},
 
 {".cmx", "image/x-cmx"},
 
 {".cnf", "text/plain"},
 
 {".cod", "image/cis-cod"},
 
 {".config", "application/xml"},
 
 {".contact", "text/x-ms-contact"},
 
 {".coverage", "application/xml"},
 
 {".cpio", "application/x-cpio"},
 
 {".cpp", "text/plain"},
 
 {".crd", "application/x-mscardfile"},
 
 {".crl", "application/pkix-crl"},
 
 {".crt", "application/x-x509-ca-cert"},
 
 {".cs", "text/plain"},
 
 {".csdproj", "text/plain"},
 
 {".csh", "application/x-csh"},
 
 {".csproj", "text/plain"},
 
 {".css", "text/css"},
 
 {".csv", "text/csv"},
 
 {".cur", "application/octet-stream"},
 
 {".cxx", "text/plain"},
 
 {".dat", "application/octet-stream"},
 
 {".datasource", "application/xml"},
 
 {".dbproj", "text/plain"},
 
 {".dcr", "application/x-director"},
 
 {".def", "text/plain"},
 
 {".deploy", "application/octet-stream"},
 
 {".der", "application/x-x509-ca-cert"},
 
 {".dgml", "application/xml"},
 
 {".dib", "image/bmp"},
 
 {".dif", "video/x-dv"},
 
 {".dir", "application/x-director"},
 
 {".disco", "text/xml"},
 
 {".dll", "application/x-msdownload"},
 
 {".dll.config", "text/xml"},
 
 {".dlm", "text/dlm"},
 
 {".doc", "application/msword"},
 
 {".docm", "application/vnd.ms-word.document.macroEnabled.12"},
 
 {".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"},
 
 {".dot", "application/msword"},
 
 {".dotm", "application/vnd.ms-word.template.macroEnabled.12"},
 
 {".dotx", "application/vnd.openxmlformats-officedocument.wordprocessingml.template"},
 
 {".dsp", "application/octet-stream"},
 
 {".dsw", "text/plain"},
 
 {".dtd", "text/xml"},
 
 {".dtsConfig", "text/xml"},
 
 {".dv", "video/x-dv"},
 
 {".dvi", "application/x-dvi"},
 
 {".dwf", "drawing/x-dwf"},
 
 {".dwp", "application/octet-stream"},
 
 {".dxr", "application/x-director"},
 
 {".eml", "message/rfc822"},
 
 {".emz", "application/octet-stream"},
 
 {".eot", "application/octet-stream"},
 
 {".eps", "application/postscript"},
 
 {".etl", "application/etl"},
 
 {".etx", "text/x-setext"},
 
 {".evy", "application/envoy"},
 
 {".exe", "application/octet-stream"},
 
 {".exe.config", "text/xml"},
 
 {".fdf", "application/vnd.fdf"},
 
 {".fif", "application/fractals"},
 
 {".filters", "Application/xml"},
 
 {".fla", "application/octet-stream"},
 
 {".flr", "x-world/x-vrml"},
 
 {".flv", "video/x-flv"},
 
 {".fsscript", "application/fsharp-script"},
 
 {".fsx", "application/fsharp-script"},
 
 {".generictest", "application/xml"},
 
 {".gif", "image/gif"},
 
 {".group", "text/x-ms-group"},
 
 {".gsm", "audio/x-gsm"},
 
 {".gtar", "application/x-gtar"},
 
 {".gz", "application/x-gzip"},
 
 {".h", "text/plain"},
 
 {".hdf", "application/x-hdf"},
 
 {".hdml", "text/x-hdml"},
 
 {".hhc", "application/x-oleobject"},
 
 {".hhk", "application/octet-stream"},
 
 {".hhp", "application/octet-stream"},
 
 {".hlp", "application/winhlp"},
 
 {".hpp", "text/plain"},
 
 {".hqx", "application/mac-binhex40"},
 
 {".hta", "application/hta"},
 
 {".htc", "text/x-component"},
 
 {".htm", "text/html"},
 
 {".html", "text/html"},
 
 {".htt", "text/webviewhtml"},
 
 {".hxa", "application/xml"},
 
 {".hxc", "application/xml"},
 
 {".hxd", "application/octet-stream"},
 
 {".hxe", "application/xml"},
 
 {".hxf", "application/xml"},
 
 {".hxh", "application/octet-stream"},
 
 {".hxi", "application/octet-stream"},
 
 {".hxk", "application/xml"},
 
 {".hxq", "application/octet-stream"},
 
 {".hxr", "application/octet-stream"},
 
 {".hxs", "application/octet-stream"},
 
 {".hxt", "text/html"},
 
 {".hxv", "application/xml"},
 
 {".hxw", "application/octet-stream"},
 
 {".hxx", "text/plain"},
 
 {".i", "text/plain"},
 
 {".ico", "image/x-icon"},
 
 {".ics", "application/octet-stream"},
 
 {".idl", "text/plain"},
 
 {".ief", "image/ief"},
 
 {".iii", "application/x-iphone"},
 
 {".inc", "text/plain"},
 
 {".inf", "application/octet-stream"},
 
 {".inl", "text/plain"},
 
 {".ins", "application/x-internet-signup"},
 
 {".ipa", "application/x-itunes-ipa"},
 
 {".ipg", "application/x-itunes-ipg"},
 
 {".ipproj", "text/plain"},
 
 {".ipsw", "application/x-itunes-ipsw"},
 
 {".iqy", "text/x-ms-iqy"},
 
 {".isp", "application/x-internet-signup"},
 
 {".ite", "application/x-itunes-ite"},
 
 {".itlp", "application/x-itunes-itlp"},
 
 {".itms", "application/x-itunes-itms"},
 
 {".itpc", "application/x-itunes-itpc"},
 
 {".IVF", "video/x-ivf"},
 
 {".jar", "application/java-archive"},
 
 {".java", "application/octet-stream"},
 
 {".jck", "application/liquidmotion"},
 
 {".jcz", "application/liquidmotion"},
 
 {".jfif", "image/pjpeg"},
 
 {".jnlp", "application/x-java-jnlp-file"},
 
 {".jpb", "application/octet-stream"},
 
 {".jpe", "image/jpeg"},
 
 {".jpeg", "image/jpeg"},
 
 {".jpg", "image/jpeg"},
 
 {".js", "application/x-javascript"},
 
 {".jsx", "text/jscript"},
 
 {".jsxbin", "text/plain"},
 
 {".latex", "application/x-latex"},
 
 {".library-ms", "application/windows-library+xml"},
 
 {".lit", "application/x-ms-reader"},
 
 {".loadtest", "application/xml"},
 
 {".lpk", "application/octet-stream"},
 
 {".lsf", "video/x-la-asf"},
 
 {".lst", "text/plain"},
 
 {".lsx", "video/x-la-asf"},
 
 {".lzh", "application/octet-stream"},
 
 {".m13", "application/x-msmediaview"},
 
 {".m14", "application/x-msmediaview"},
 
 {".m1v", "video/mpeg"},
 
 {".m2t", "video/vnd.dlna.mpeg-tts"},
 
 {".m2ts", "video/vnd.dlna.mpeg-tts"},
 
 {".m2v", "video/mpeg"},
 
 {".m3u", "audio/x-mpegurl"},
 
 {".m3u8", "audio/x-mpegurl"},
 
 {".m4a", "audio/m4a"},
 
 {".m4b", "audio/m4b"},
 
 {".m4p", "audio/m4p"},
 
 {".m4r", "audio/x-m4r"},
 
 {".m4v", "video/x-m4v"},
 
 {".mac", "image/x-macpaint"},
 
 {".mak", "text/plain"},
 
 {".man", "application/x-troff-man"},
 
 {".manifest", "application/x-ms-manifest"},
 
 {".map", "text/plain"},
 
 {".master", "application/xml"},
 
 {".mda", "application/msaccess"},
 
 {".mdb", "application/x-msaccess"},
 
 {".mde", "application/msaccess"},
 
 {".mdp", "application/octet-stream"},
 
 {".me", "application/x-troff-me"},
 
 {".mfp", "application/x-shockwave-flash"},
 
 {".mht", "message/rfc822"},
 
 {".mhtml", "message/rfc822"},
 
 {".mid", "audio/mid"},
 
 {".midi", "audio/mid"},
 
 {".mix", "application/octet-stream"},
 
 {".mk", "text/plain"},
 
 {".mmf", "application/x-smaf"},
 
 {".mno", "text/xml"},
 
 {".mny", "application/x-msmoney"},
 
 {".mod", "video/mpeg"},
 
 {".mov", "video/quicktime"},
 
 {".movie", "video/x-sgi-movie"},
 
 {".mp2", "video/mpeg"},
 
 {".mp2v", "video/mpeg"},
 
 {".mp3", "audio/mpeg"},
 
 {".mp4", "video/mp4"},
 
 {".mp4v", "video/mp4"},
 
 {".mpa", "video/mpeg"},
 
 {".mpe", "video/mpeg"},
 
 {".mpeg", "video/mpeg"},
 
 {".mpf", "application/vnd.ms-mediapackage"},
 
 {".mpg", "video/mpeg"},
 
 {".mpp", "application/vnd.ms-project"},
 
 {".mpv2", "video/mpeg"},
 
 {".mqv", "video/quicktime"},
 
 {".ms", "application/x-troff-ms"},
 
 {".msi", "application/octet-stream"},
 
 {".mso", "application/octet-stream"},
 
 {".mts", "video/vnd.dlna.mpeg-tts"},
 
 {".mtx", "application/xml"},
 
 {".mvb", "application/x-msmediaview"},
 
 {".mvc", "application/x-miva-compiled"},
 
 {".mxp", "application/x-mmxp"},
 
 {".nc", "application/x-netcdf"},
 
 {".nsc", "video/x-ms-asf"},
 
 {".nws", "message/rfc822"},
 
 {".ocx", "application/octet-stream"},
 
 {".oda", "application/oda"},
 
 {".odc", "text/x-ms-odc"},
 
 {".odh", "text/plain"},
 
 {".odl", "text/plain"},
 
 {".odp", "application/vnd.oasis.opendocument.presentation"},
 
 {".ods", "application/oleobject"},
 
 {".odt", "application/vnd.oasis.opendocument.text"},
 
 {".one", "application/onenote"},
 
 {".onea", "application/onenote"},
 
 {".onepkg", "application/onenote"},
 
 {".onetmp", "application/onenote"},
 
 {".onetoc", "application/onenote"},
 
 {".onetoc2", "application/onenote"},
 
 {".orderedtest", "application/xml"},
 
 {".osdx", "application/opensearchdescription+xml"},
 
 {".p10", "application/pkcs10"},
 
 {".p12", "application/x-pkcs12"},
 
 {".p7b", "application/x-pkcs7-certificates"},
 
 {".p7c", "application/pkcs7-mime"},
 
 {".p7m", "application/pkcs7-mime"},
 
 {".p7r", "application/x-pkcs7-certreqresp"},
 
 {".p7s", "application/pkcs7-signature"},
 
 {".pbm", "image/x-portable-bitmap"},
 
 {".pcast", "application/x-podcast"},
 
 {".pct", "image/pict"},
 
 {".pcx", "application/octet-stream"},
 
 {".pcz", "application/octet-stream"},
 
 {".pdf", "application/pdf"},
 
 {".pfb", "application/octet-stream"},
 
 {".pfm", "application/octet-stream"},
 
 {".pfx", "application/x-pkcs12"},
 
 {".pgm", "image/x-portable-graymap"},
 
 {".pic", "image/pict"},
 
 {".pict", "image/pict"},
 
 {".pkgdef", "text/plain"},
 
 {".pkgundef", "text/plain"},
 
 {".pko", "application/vnd.ms-pki.pko"},
 
 {".pls", "audio/scpls"},
 
 {".pma", "application/x-perfmon"},
 
 {".pmc", "application/x-perfmon"},
 
 {".pml", "application/x-perfmon"},
 
 {".pmr", "application/x-perfmon"},
 
 {".pmw", "application/x-perfmon"},
 
 {".png", "image/png"},
 
 {".pnm", "image/x-portable-anymap"},
 
 {".pnt", "image/x-macpaint"},
 
 {".pntg", "image/x-macpaint"},
 
 {".pnz", "image/png"},
 
 {".pot", "application/vnd.ms-powerpoint"},
 
 {".potm", "application/vnd.ms-powerpoint.template.macroEnabled.12"},
 
 {".potx", "application/vnd.openxmlformats-officedocument.presentationml.template"},
 
 {".ppa", "application/vnd.ms-powerpoint"},
 
 {".ppam", "application/vnd.ms-powerpoint.addin.macroEnabled.12"},
 
 {".ppm", "image/x-portable-pixmap"},
 
 {".pps", "application/vnd.ms-powerpoint"},
 
 {".ppsm", "application/vnd.ms-powerpoint.slideshow.macroEnabled.12"},
 
 {".ppsx", "application/vnd.openxmlformats-officedocument.presentationml.slideshow"},
 
 {".ppt", "application/vnd.ms-powerpoint"},
 
 {".pptm", "application/vnd.ms-powerpoint.presentation.macroEnabled.12"},
 
 {".pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation"},
 
 {".prf", "application/pics-rules"},
 
 {".prm", "application/octet-stream"},
 
 {".prx", "application/octet-stream"},
 
 {".ps", "application/postscript"},
 
 {".psc1", "application/PowerShell"},
 
 {".psd", "application/octet-stream"},
 
 {".psess", "application/xml"},
 
 {".psm", "application/octet-stream"},
 
 {".psp", "application/octet-stream"},
 
 {".pub", "application/x-mspublisher"},
 
 {".pwz", "application/vnd.ms-powerpoint"},
 
 {".qht", "text/x-html-insertion"},
 
 {".qhtm", "text/x-html-insertion"},
 
 {".qt", "video/quicktime"},
 
 {".qti", "image/x-quicktime"},
 
 {".qtif", "image/x-quicktime"},
 
 {".qtl", "application/x-quicktimeplayer"},
 
 {".qxd", "application/octet-stream"},
 
 {".ra", "audio/x-pn-realaudio"},
 
 {".ram", "audio/x-pn-realaudio"},
 
 {".rar", "application/octet-stream"},
 
 {".ras", "image/x-cmu-raster"},
 
 {".rat", "application/rat-file"},
 
 {".rc", "text/plain"},
 
 {".rc2", "text/plain"},
 
 {".rct", "text/plain"},
 
 {".rdlc", "application/xml"},
 
 {".resx", "application/xml"},
 
 {".rf", "image/vnd.rn-realflash"},
 
 {".rgb", "image/x-rgb"},
 
 {".rgs", "text/plain"},
 
 {".rm", "application/vnd.rn-realmedia"},
 
 {".rmi", "audio/mid"},
 
 {".rmp", "application/vnd.rn-rn_music_package"},
 
 {".roff", "application/x-troff"},
 
 {".rpm", "audio/x-pn-realaudio-plugin"},
 
 {".rqy", "text/x-ms-rqy"},
 
 {".rtf", "application/rtf"},
 
 {".rtx", "text/richtext"},
 
 {".ruleset", "application/xml"},
 
 {".s", "text/plain"},
 
 {".safariextz", "application/x-safari-safariextz"},
 
 {".scd", "application/x-msschedule"},
 
 {".sct", "text/scriptlet"},
 
 {".sd2", "audio/x-sd2"},
 
 {".sdp", "application/sdp"},
 
 {".sea", "application/octet-stream"},
 
 {".searchConnector-ms", "application/windows-search-connector+xml"},
 
 {".setpay", "application/set-payment-initiation"},
 
 {".setreg", "application/set-registration-initiation"},
 
 {".settings", "application/xml"},
 
 {".sgimb", "application/x-sgimb"},
 
 {".sgml", "text/sgml"},
 
 {".sh", "application/x-sh"},
 
 {".shar", "application/x-shar"},
 
 {".shtml", "text/html"},
 
 {".sit", "application/x-stuffit"},
 
 {".sitemap", "application/xml"},
 
 {".skin", "application/xml"},
 
 {".sldm", "application/vnd.ms-powerpoint.slide.macroEnabled.12"},
 
 {".sldx", "application/vnd.openxmlformats-officedocument.presentationml.slide"},
 
 {".slk", "application/vnd.ms-excel"},
 
 {".sln", "text/plain"},
 
 {".slupkg-ms", "application/x-ms-license"},
 
 {".smd", "audio/x-smd"},
 
 {".smi", "application/octet-stream"},
 
 {".smx", "audio/x-smd"},
 
 {".smz", "audio/x-smd"},
 
 {".snd", "audio/basic"},
 
 {".snippet", "application/xml"},
 
 {".snp", "application/octet-stream"},
 
 {".sol", "text/plain"},
 
 {".sor", "text/plain"},
 
 {".spc", "application/x-pkcs7-certificates"},
 
 {".spl", "application/futuresplash"},
 
 {".src", "application/x-wais-source"},
 
 {".srf", "text/plain"},
 
 {".SSISDeploymentManifest", "text/xml"},
 
 {".ssm", "application/streamingmedia"},
 
 {".sst", "application/vnd.ms-pki.certstore"},
 
 {".stl", "application/vnd.ms-pki.stl"},
 
 {".sv4cpio", "application/x-sv4cpio"},
 
 {".sv4crc", "application/x-sv4crc"},
 
 {".svc", "application/xml"},
 
 {".swf", "application/x-shockwave-flash"},
 
 {".t", "application/x-troff"},
 
 {".tar", "application/x-tar"},
 
 {".tcl", "application/x-tcl"},
 
 {".testrunconfig", "application/xml"},
 
 {".testsettings", "application/xml"},
 
 {".tex", "application/x-tex"},
 
 {".texi", "application/x-texinfo"},
 
 {".texinfo", "application/x-texinfo"},
 
 {".tgz", "application/x-compressed"},
 
 {".thmx", "application/vnd.ms-officetheme"},
 
 {".thn", "application/octet-stream"},
 
 {".tif", "image/tiff"},
 
 {".tiff", "image/tiff"},
 
 {".tlh", "text/plain"},
 
 {".tli", "text/plain"},
 
 {".toc", "application/octet-stream"},
 
 {".tr", "application/x-troff"},
 
 {".trm", "application/x-msterminal"},
 
 {".trx", "application/xml"},
 
 {".ts", "video/vnd.dlna.mpeg-tts"},
 
 {".tsv", "text/tab-separated-values"},
 
 {".ttf", "application/octet-stream"},
 
 {".tts", "video/vnd.dlna.mpeg-tts"},
 
 {".txt", "text/plain"},
 
 {".u32", "application/octet-stream"},
 
 {".uls", "text/iuls"},
 
 {".user", "text/plain"},
 
 {".ustar", "application/x-ustar"},
 
 {".vb", "text/plain"},
 
 {".vbdproj", "text/plain"},
 
 {".vbk", "video/mpeg"},
 
 {".vbproj", "text/plain"},
 
 {".vbs", "text/vbscript"},
 
 {".vcf", "text/x-vcard"},
 
 {".vcproj", "Application/xml"},
 
 {".vcs", "text/plain"},
 
 {".vcxproj", "Application/xml"},
 
 {".vddproj", "text/plain"},
 
 {".vdp", "text/plain"},
 
 {".vdproj", "text/plain"},
 
 {".vdx", "application/vnd.ms-visio.viewer"},
 
 {".vml", "text/xml"},
 
 {".vscontent", "application/xml"},
 
 {".vsct", "text/xml"},
 
 {".vsd", "application/vnd.visio"},
 
 {".vsi", "application/ms-vsi"},
 
 {".vsix", "application/vsix"},
 
 {".vsixlangpack", "text/xml"},
 
 {".vsixmanifest", "text/xml"},
 
 {".vsmdi", "application/xml"},
 
 {".vspscc", "text/plain"},
 
 {".vss", "application/vnd.visio"},
 
 {".vsscc", "text/plain"},
 
 {".vssettings", "text/xml"},
 
 {".vssscc", "text/plain"},
 
 {".vst", "application/vnd.visio"},
 
 {".vstemplate", "text/xml"},
 
 {".vsto", "application/x-ms-vsto"},
 
 {".vsw", "application/vnd.visio"},
 
 {".vsx", "application/vnd.visio"},
 
 {".vtx", "application/vnd.visio"},
 
 {".wav", "audio/wav"},
 
 {".wave", "audio/wav"},
 
 {".wax", "audio/x-ms-wax"},
 
 {".wbk", "application/msword"},
 
 {".wbmp", "image/vnd.wap.wbmp"},
 
 {".wcm", "application/vnd.ms-works"},
 
 {".wdb", "application/vnd.ms-works"},
 
 {".wdp", "image/vnd.ms-photo"},
 
 {".webarchive", "application/x-safari-webarchive"},
 
 {".webtest", "application/xml"},
 
 {".wiq", "application/xml"},
 
 {".wiz", "application/msword"},
 
 {".wks", "application/vnd.ms-works"},
 
 {".WLMP", "application/wlmoviemaker"},
 
 {".wlpginstall", "application/x-wlpg-detect"},
 
 {".wlpginstall3", "application/x-wlpg3-detect"},
 
 {".wm", "video/x-ms-wm"},
 
 {".wma", "audio/x-ms-wma"},
 
 {".wmd", "application/x-ms-wmd"},
 
 {".wmf", "application/x-msmetafile"},
 
 {".wml", "text/vnd.wap.wml"},
 
 {".wmlc", "application/vnd.wap.wmlc"},
 
 {".wmls", "text/vnd.wap.wmlscript"},
 
 {".wmlsc", "application/vnd.wap.wmlscriptc"},
 
 {".wmp", "video/x-ms-wmp"},
 
 {".wmv", "video/x-ms-wmv"},
 
 {".wmx", "video/x-ms-wmx"},
 
 {".wmz", "application/x-ms-wmz"},
 
 {".wpl", "application/vnd.ms-wpl"},
 
 {".wps", "application/vnd.ms-works"},
 
 {".wri", "application/x-mswrite"},
 
 {".wrl", "x-world/x-vrml"},
 
 {".wrz", "x-world/x-vrml"},
 
 {".wsc", "text/scriptlet"},
 
 {".wsdl", "text/xml"},
 
 {".wvx", "video/x-ms-wvx"},
 
 {".x", "application/directx"},
 
 {".xaf", "x-world/x-vrml"},
 
 {".xaml", "application/xaml+xml"},
 
 {".xap", "application/x-silverlight-app"},
 
 {".xbap", "application/x-ms-xbap"},
 
 {".xbm", "image/x-xbitmap"},
 
 {".xdr", "text/plain"},
 
 {".xht", "application/xhtml+xml"},
 
 {".xhtml", "application/xhtml+xml"},
 
 {".xla", "application/vnd.ms-excel"},
 
 {".xlam", "application/vnd.ms-excel.addin.macroEnabled.12"},
 
 {".xlc", "application/vnd.ms-excel"},
 
 {".xld", "application/vnd.ms-excel"},
 
 {".xlk", "application/vnd.ms-excel"},
 
 {".xll", "application/vnd.ms-excel"},
 
 {".xlm", "application/vnd.ms-excel"},
 
 {".xls", "application/vnd.ms-excel"},
 
 {".xlsb", "application/vnd.ms-excel.sheet.binary.macroEnabled.12"},
 
 {".xlsm", "application/vnd.ms-excel.sheet.macroEnabled.12"},
 
 {".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
 
 {".xlt", "application/vnd.ms-excel"},
 
 {".xltm", "application/vnd.ms-excel.template.macroEnabled.12"},
 
 {".xltx", "application/vnd.openxmlformats-officedocument.spreadsheetml.template"},
 
 {".xlw", "application/vnd.ms-excel"},
 
 {".xml", "text/xml"},
 
 {".xmta", "application/xml"},
 
 {".xof", "x-world/x-vrml"},
 
 {".XOML", "text/plain"},
 
 {".xpm", "image/x-xpixmap"},
 
 {".xps", "application/vnd.ms-xpsdocument"},
 
 {".xrm-ms", "text/xml"},
 
 {".xsc", "application/xml"},
 
 {".xsd", "text/xml"},
 
 {".xsf", "text/xml"},
 
 {".xsl", "text/xml"},
 
 {".xslt", "text/xml"},
 
 {".xsn", "application/octet-stream"},
 
 {".xss", "application/xml"},
 
 {".xtp", "application/octet-stream"},
 
 {".xwd", "image/x-xwindowdump"},
 
 {".z", "application/x-compress"},
 
 {".zip", "application/x-zip-compressed"},
 
 #endregion
 
 
 };
 
 
 public static string GetMimeType(string extension)
 
 {
 
 if (extension == null)
 
 {
 
 throw new ArgumentNullException("extension");
 
 }
 
 
 if (!extension.StartsWith("."))
 
 {
 
 extension = "." + extension;
 
 }
 
 
 string mime;
 
 
 return _mappings.TryGetValue(extension, out mime) ? mime :"application/octet-stream";
 
 }
 
 }

上面获取Content-Type的三种方法各有利弊，要根据不同的使用环境选择。

[Http Content-Type]: http://www.nmtree.net/content-type-reference