内容类型扩展名
是否有内置函数根据文件扩展名返回内容类型？
从来没听说过。 但是你可以使用这段代码：
using Microsoft.Win32; RegistryKey key = Registry.ClassesRoot.OpenSubKey(extension); string contentType = key.GetValue("Content Type").ToString(); 您需要添加额外的代码以进行error handling。
注意：扩展名需要以点为前缀，例如.txt 。
FYKI，检查\ HKEY_CLASSES_ROOT \ MIME \ Database \ Content Type下的注册表。 将有内容类型和文件扩展名列表。 如果您可以通过Windows API加载此信息，那么您可以将文件扩展名转换为内容类型映射。
心连心
更新：[来源] [1]
public string GetMIMEType(string filepath) { FileInfo fileInfo = new FileInfo(filepath); string fileExtension = fileInfo.Extension.ToLower(); // direct mapping which is fast and ensures these extensions are found switch (fileExtension) { case "htm": case "html": return "text/html"; case "js": return "text/javascript"; // registry may return "application/x-javascript" } // see if we can find extension info anywhere in the registry //Note : there is not a ContentType key under ALL the file types , check Run --> regedit , then extensions !!! RegistryPermission regPerm = new RegistryPermission(RegistryPermissionAccess.Read, @"\\HKEY_CLASSES_ROOT"); // looks for extension with a content type RegistryKey rkContentTypes = Registry.ClassesRoot.OpenSubKey(fileExtension); if (rkContentTypes != null) { object key = rkContentTypes.GetValue("Content Type"); if (key != null) return key.ToString().ToLower(); } // looks for a content type with extension // Note : This would be problem if multiple extensions associate with one content type. RegistryKey typeKey = Registry.ClassesRoot.OpenSubKey(@"MIME\Database\Content Type"); foreach (string keyname in typeKey.GetSubKeyNames()) { RegistryKey curKey = typeKey.OpenSubKey(keyname); if (curKey != null) { object extension = curKey.GetValue("Extension"); if (extension != null) { if (extension.ToString().ToLower() == fileExtension) { return keyname; } } } } return null; }
[1]： http ： //www.codeproject.com/KB/dotnet/ContentType.aspx？ enter code here = enter code here
从.Net Framework 4.5开始，有一个类System.Web.MimeMapping ，它有一个完整的mime类型库，其中包含获取请求的mime类型的方法。
请参阅： http ： //msdn.microsoft.com/en-us/library/system.web.mimemapping(v=vs.110).aspx
或者用于实现GetMimeMapping ： https ： GetMimeMapping
如果是上传的文件。 您可以将contenttype存储在数据库的列中，以便以后在上载文件时使用。 HttpPostedFile类有一个名为ContentType的属性。
有关或多或少的完整列表，请查看下面的地图（C ++，但它可以直接将其更改为C＃）。
这就是Google / Chrome识别内容类型表单文件扩展的方式（不知道如何生成电子邮件正文 – 通过客户端的JavaScript或服务器端的POST – 我的猜测是后者）。 我使用以下技巧获得此列表：
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搜索了互联网上最常用的文件扩展名。 很幸运能找到一个html表，以便我可以将它复制粘贴到Excel中，以获得一个只有扩展的干净列表。
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创建了一个包含少量内容字符的小文件测试 。
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使用（2）中的扩展列表和一些命令行魔术来创建文件test.TXT，test.HTM，test.TIFF等。 Linux变种
for file in test.TXT test.HTM test.TIFF ... ; do cp test "$file"; done;for file in test.TXT test.HTM test.TIFF ... ; do cp test "$file"; done; -
将所有这些文件作为附件发送到我的Gmail。 请注意，出于安全原因，某些文件（如.exe和.zip）已被过滤掉。 它们在下面的代码中丢失了！
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在gmail中，下载了原文，有一个可以看到
Content-Type: application/pdf; name="example.pdf"每个附加文件的Content-Type: application/pdf; name="example.pdf"行。 在VIM中解析了以下列表。
如果要添加下面列表中没有的扩展名 – 创建小文件sample.xyz ，请将其发送给自己并查看Content-Type的原始电子邮件。 这就是诀窍。 希望能帮助到你！
PS我知道它不是最好的列表但是我已经足够了解如何以编程方式发送电子邮件附件并选择Content-Type by file extension和gmail一样好。 如果某些扩展类型“缺失”，请不要苛刻。
static const map ContentTypes = { { "TXT","text/plain" }, { "HTM","text/html" }, { "TIFF","image/tiff" }, { "TMP","application/octet-stream" }, { "TOAST","application/octet-stream" }, { "TORRENT","application/x-bittorrent" }, { "TTF","application/x-font-ttf" }, { "UUE","application/octet-stream" }, { "VCD","application/x-cdlink" }, { "VCF","text/x-vcard" }, { "VCXPROJ","application/xml" }, { "VOB","application/octet-stream" }, { "WAV","audio/x-wav" }, { "WMA","audio/x-ms-wma" }, { "WMV","video/x-ms-wmv" }, { "WPD","application/wordperfect" }, { "WPS","application/octet-stream" }, { "XCODEPROJ","application/octet-stream" }, { "XHTML","application/xhtml+xml" }, { "XLR","application/octet-stream" }, { "XLS","application/vnd.ms-excel" }, { "XLSX","application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" }, { "XML","text/xml" }, { "YUV","application/octet-stream" }, { "ZIPX","application/octet-stream" }, { "3DM","application/octet-stream" }, { "3DS","application/octet-stream" }, { "3G2","video/3gpp2" }, { "3GP","video/3gpp" }, { "ACCDB","application/octet-stream" }, { "AI","application/illustrator" }, { "AIF","audio/x-aiff" }, { "APK","application/vnd.android.package-archive" }, { "APP","application/octet-stream" }, { "ASF","video/x-ms-asf" }, { "ASP","application/octet-stream" }, { "ASPX","application/xml" }, { "AVI","video/x-msvideo" }, { "BAK","application/octet-stream" }, { "BIN","application/octet-stream" }, { "BMP","image/bmp" }, { "C","text/x-csrc" }, { "CAB","application/octet-stream" }, { "CBR","application/octet-stream" }, { "CER","application/x-x509-ca-cert" }, { "CFG","application/octet-stream" }, { "CFM","application/octet-stream" }, { "CGI","application/octet-stream" }, { "CLASS","application/octet-stream" }, { "CPP","text/x-c++src" }, { "CRDOWNLOAD","application/octet-stream" }, { "CRX","application/x-chrome-extension" }, { "CS","text/plain" }, { "CSR","application/octet-stream" }, { "CSS","text/css" }, { "CSV","text/csv" }, { "CUE","application/octet-stream" }, { "CUR","application/octet-stream" }, { "DAT","application/octet-stream" }, { "DB","application/octet-stream" }, { "DBF","application/octet-stream" }, { "DDS","image/vnd.ms-dds" }, { "DEB","application/x-debian-package" }, { "DEM","application/octet-stream" }, { "DESKTHEMEPACK","application/octet-stream" }, { "DLL","application/octet-stream" }, { "DMG","application/octet-stream" }, { "DMP","application/octet-stream" }, { "DOC","application/msword" }, { "DOCX","application/vnd.openxmlformats-officedocument.wordprocessingml.document" }, { "DRV","application/octet-stream" }, { "DTD","application/xml-dtd" }, { "DWG","application/octet-stream" }, { "DXF","application/dxf" }, { "EPS","application/postscript" }, { "FLA","application/octet-stream" }, { "FLV","video/x-flv" }, { "FNT","application/octet-stream+fnt" }, { "FON","application/octet-stream+fon" }, { "GADGET","application/octet-stream" }, { "GAM","application/octet-stream" }, { "GED","application/octet-stream" }, { "GIF","image/gif" }, { "GPX","application/gpx+xml" }, { "GZ","application/x-gzip" }, { "H","text/x-chdr" }, { "HQX","application/mac-binhex40" }, { "HTML","text/html" }, { "ICNS","application/octet-stream" }, { "ICO","image/x-icon" }, { "ICS","text/calendar" }, { "IFF","application/octet-stream" }, { "INDD","application/octet-stream" }, { "INI","application/octet-stream" }, { "ISO","application/octet-stream" }, { "JAVA","application/octet-stream" }, { "JPG","image/jpeg" }, { "JSP","application/octet-stream" }, { "KEY","application/octet-stream" }, { "KEYCHAIN","application/octet-stream" }, { "KML","application/vnd.google-earth.kml+xml" }, { "KMZ","application/vnd.google-earth.kmz" }, { "LOG","application/octet-stream" }, { "LUA","application/octet-stream" }, { "M","application/octet-stream" }, { "M3U","audio/x-mpegurl" }, { "M4A","audio/mp4" }, { "M4V","video/x-m4v" }, { "MAX","application/octet-stream" }, { "MDB","application/octet-stream" }, { "MDF","application/octet-stream" }, { "MID","audio/midi" }, { "MIM","application/octet-stream" }, { "MOV","video/quicktime" }, { "MP3","audio/mpeg" }, { "MP4","video/mp4" }, { "MPA","audio/mpeg" }, { "MPG","video/mpeg" }, { "MSG","application/octet-stream" }, { "NES","application/octet-stream" }, { "OBJ","application/octet-stream" }, { "ODT","application/vnd.oasis.opendocument.text" }, { "OTF","application/vnd.oasis.opendocument.formula-template" }, { "PAGES","application/x-iwork-pages-sffpages" }, { "PART","application/octet-stream" }, { "PCT","application/octet-stream" }, { "PDB","chemical/x-pdb" }, { "PDF","application/pdf" }, { "PHP","application/x-httpd-php" }, { "PKG","application/octet-stream" }, { "PL","application/octet-stream" }, { "PLUGIN","application/octet-stream" }, { "PNG","image/png" }, { "PPS","application/vnd.ms-powerpoint" }, { "PPT","application/vnd.ms-powerpoint" }, { "PPTX","application/vnd.openxmlformats-officedocument.presentationml.presentation" }, { "PRF","application/pics-rules" }, { "PS","application/postscript" }, { "PSD","application/photoshop" }, { "PSPIMAGE","application/octet-stream" }, { "PY","application/octet-stream" }, { "RM","audio/x-pn-realaudio" }, { "ROM","application/octet-stream" }, { "RPM","application/x-rpm" }, { "RSS","application/octet-stream" }, { "RTF","application/rtf" }, { "SAV","application/octet-stream" }, { "SDF","application/octet-stream" }, { "SH","application/x-sh" }, { "SITX","application/octet-stream" }, { "SLN","text/plain" }, { "SQL","application/octet-stream" }, { "SRT","application/octet-stream" }, { "SVG","image/svg+xml" }, { "SWF","application/x-shockwave-flash" }, { "SWIFT","application/octet-stream" }, { "TAX2016","application/octet-stream" }, { "TEX","application/x-tex" } };
这是我写的一个：
public string GetContentTypeByExtension(string strExtension) { switch (strExtension) { case ".fif": return "application/fractals"; break; case ".hta": return "application/hta"; break; case ".hqx": return "application/mac-binhex40"; break; case ".vsi": return "application/ms-vsi"; break; case ".p10": return "application/pkcs10"; break; case ".p7m": return "application/pkcs7-mime"; break; case ".p7s": return "application/pkcs7-signature"; break; case ".cer": return "application/pkix-cert"; break; case ".crl": return "application/pkix-crl"; break; case ".ps": return "application/postscript"; break; case ".setpay": return "application/set-payment-initiation"; break; case ".setreg": return "application/set-registration-initiation"; break; case ".sst": return "application/vnd.ms-pki.certstore"; break; case ".pko": return "application/vnd.ms-pki.pko"; break; case ".cat": return "application/vnd.ms-pki.seccat"; break; case ".stl": return "application/vnd.ms-pki.stl"; break; case ".wpl": return "application/vnd.ms-wpl"; break; case ".xps": return "application/vnd.ms-xpsdocument"; break; case ".z": return "application/x-compress"; break; case ".tgz": return "application/x-compressed"; break; case ".gz": return "application/x-gzip"; break; case ".ins": return "application/x-internet-signup"; break; case ".iii": return "application/x-iphone"; break; case ".jtx": return "application/x-jtx+xps"; break; case ".latex": return "application/x-latex"; break; case ".nix": return "application/x-mix-transfer"; break; case ".asx": return "application/x-mplayer2"; break; case ".application": return "application/x-ms-application"; break; case ".wmd": return "application/x-ms-wmd"; break; case ".wmz": return "application/x-ms-wmz"; break; case ".xbap": return "application/x-ms-xbap"; break; case ".p12": return "application/x-pkcs12"; break; case ".p7b": return "application/x-pkcs7-certificates"; break; case ".p7r": return "application/x-pkcs7-certreqresp"; break; case ".sit": return "application/x-stuffit"; break; case ".tar": return "application/x-tar"; break; case ".man": return "application/x-troff-man"; break; case ".cer": return "application/x-x509-ca-cert"; break; case ".zip": return "application/x-zip-compressed"; break; case ".xaml": return "application/xaml+xml"; break; case ".xml": return "application/xml"; break; case ".aiff": return "audio/aiff"; break; case ".au": return "audio/basic"; break; case ".mid": return "audio/mid"; break; case ".mid": return "audio/midi"; break; case ".mp3": return "audio/mp3"; break; case ".mp3": return "audio/mpeg"; break; case ".m3u": return "audio/mpegurl"; break; case ".mp3": return "audio/mpg"; break; case ".wav": return "audio/wav"; break; case ".aiff": return "audio/x-aiff"; break; case ".mid": return "audio/x-mid"; break; case ".mid": return "audio/x-midi"; break; case ".mp3": return "audio/x-mp3"; break; case ".mp3": return "audio/x-mpeg"; break; case ".m3u": return "audio/x-mpegurl"; break; case ".mp3": return "audio/x-mpg"; break; case ".wax": return "audio/x-ms-wax"; break; case ".wma": return "audio/x-ms-wma"; break; case ".wav": return "audio/x-wav"; break; case ".bmp": return "image/bmp"; break; case ".gif": return "image/gif"; break; case ".jpg": return "image/jpeg"; break; case ".jpg": return "image/pjpeg"; break; case ".png": return "image/png"; break; case ".tiff": return "image/tiff"; break; case ".ico": return "image/x-icon"; break; case ".png": return "image/x-png"; break; case ".mid": return "midi/mid"; break; case ".dwfx": return "model/vnd.dwfx+xps"; break; case ".css": return "text/css"; break; case ".323": return "text/h323"; break; case ".htm": return "text/html"; break; case ".uls": return "text/iuls"; break; case ".txt": return "text/plain"; break; case ".wsc": return "text/scriptlet"; break; case ".htt": return "text/webviewhtml"; break; case ".htc": return "text/x-component"; break; case ".vcf": return "text/x-vcard"; break; case ".xml": return "text/xml"; break; case ".avi": return "video/avi"; break; case ".mpeg": return "video/mpeg"; break; case ".mpeg": return "video/mpg"; break; case ".avi": return "video/msvideo"; break; case ".mpeg": return "video/x-mpeg"; break; case ".mpeg": return "video/x-mpeg2a"; break; case ".asx": return "video/x-ms-asf"; break; case ".asx": return "video/x-ms-asf-plugin"; break; case ".wm": return "video/x-ms-wm"; break; case ".wmv": return "video/x-ms-wmv"; break; case ".wmx": return "video/x-ms-wmx"; break; case ".wvx": return "video/x-ms-wvx"; break; case ".avi": return "video/x-msvideo"; break; } }