什么是MIME
MIME(Multipurpose Internet Mail Extensions)多用途互联网邮件扩展类型。是设定某种扩展名的文件用一种应用程序来打开的方式类型，当该扩展名文件被访问的时候，浏览器会自动使用指定应用程序来打开。多用于指定一些客户端自定义的文件名，以及一些媒体文件打开方式。
它是一个互联网标准，扩展了电子邮件标准，使其能够支持：
非ASCII字符文本；非文本格式附件（二进制、声音、图像等）；由多部分（multiple parts）组成的消息体；包含非ASCII字符的头信息（Header information）。
这个标准被定义在RFC 2045、RFC 2046、RFC 2047、RFC 2048、RFC 2049等RFC中。 MIME改善了由RFC 822转变而来的RFC 2822，这些旧标准规定电子邮件标准并不允许在邮件消息中使用7位ASCII字符集以外的字符。正因如此，一些非英语字符消息和二进制文件，图像，声音等非文字消息原本都不能在电子邮件中传输(MIME可以)。MIME规定了用于表示各种各样的数据类型的符号化方法。 此外，在万维网中使用的HTTP协议中也使用了MIME的框架，标准被扩展为互联网媒体类型。
什么是ContentType
Content-Type，内容类型，一般是指网页中存在的Content-Type，用于定义网络文件的类型和网页的编码，决定浏览器将以什么形式、什么编码读取这个文件。ContentType属性指定响应的 HTTP内容类型，如果未指定 ContentType，默认为TEXT/HTML。
C#获取文件的MIME Type的方法
- 微软官方提供的MimeMapping
- 通过注册表
- 实现MimeMapping类
代码实现
微软官方提供的MimeMapping
string fileName = "nmtree.png";
var contentType = MimeMapping.GetMimeMapping(fileName);
Console.WriteLine(contentType);此类是微软官方提供的，但是需要.NET Framework 4.5及更高版本。MimeMapping类在System.Web命名空间下。
通过注册表
public static string GetMimeMapping(string fileName)
{
string mimeType = "application/octet-stream";
string ext = Path.GetExtension(fileName).ToLower();
RegistryKey regKey = Registry.ClassesRoot.OpenSubKey(ext);
if (regKey != null && regKey.GetValue("Content Type") != null)
{
mimeType = regKey.GetValue("Content Type").ToString();
}
return mimeType;
}此方法需要有访问注册表的权限。
实现MimeMapping类
public static class MimeMapping
{
private static Dictionary<string, string> _mimeMappingTable;
private static void AddMimeMapping(string extension, string MimeType)
{
MimeMapping._mimeMappingTable.Add(extension, MimeType);
}
public static string GetMimeMapping(string fileName)
{
if (string.IsNullOrWhiteSpace(fileName))
{
throw new ArgumentNullException();
}
if (!File.Exists(fileName))
{
throw new FileNotFoundException();
}
FileInfo fileInfo = new FileInfo(fileName);
string key = fileInfo.Extension;
if (!string.IsNullOrWhiteSpace(key)&&MimeMapping._mimeMappingTable.ContainsKey(key))
{
return MimeMapping._mimeMappingTable[key];
}
return "application/octet-stream";
}
static MimeMapping()
{
MimeMapping._mimeMappingTable = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
AddMimeMapping(".323", "text/h323");
AddMimeMapping(".aaf", "application/octet-stream");
AddMimeMapping(".aca", "application/octet-stream");
AddMimeMapping(".accdb", "application/msaccess");
AddMimeMapping(".accde", "application/msaccess");
AddMimeMapping(".accdt", "application/msaccess");
AddMimeMapping(".acx", "application/internet-property-stream");
AddMimeMapping(".afm", "application/octet-stream");
AddMimeMapping(".ai", "application/postscript");
AddMimeMapping(".aif", "audio/x-aiff");
AddMimeMapping(".aifc", "audio/aiff");
AddMimeMapping(".aiff", "audio/aiff");
AddMimeMapping(".application", "application/x-ms-application");
AddMimeMapping(".art", "image/x-jg");
AddMimeMapping(".asd", "application/octet-stream");
AddMimeMapping(".asf", "video/x-ms-asf");
AddMimeMapping(".asi", "application/octet-stream");
AddMimeMapping(".asm", "text/plain");
AddMimeMapping(".asr", "video/x-ms-asf");
AddMimeMapping(".asx", "video/x-ms-asf");
AddMimeMapping(".atom", "application/atom+xml");
AddMimeMapping(".au", "audio/basic");
AddMimeMapping(".avi", "video/x-msvideo");
AddMimeMapping(".axs", "application/olescript");
AddMimeMapping(".bas", "text/plain");
AddMimeMapping(".bcpio", "application/x-bcpio");
AddMimeMapping(".bin", "application/octet-stream");
AddMimeMapping(".bmp", "image/bmp");
AddMimeMapping(".c", "text/plain");
AddMimeMapping(".cab", "application/octet-stream");
AddMimeMapping(".calx", "application/vnd.ms-office.calx");
AddMimeMapping(".cat", "application/vnd.ms-pki.seccat");
AddMimeMapping(".cdf", "application/x-cdf");
AddMimeMapping(".chm", "application/octet-stream");
AddMimeMapping(".class", "application/x-java-applet");
AddMimeMapping(".clp", "application/x-msclip");
AddMimeMapping(".cmx", "image/x-cmx");
AddMimeMapping(".cnf", "text/plain");
AddMimeMapping(".cod", "image/cis-cod");
AddMimeMapping(".cpio", "application/x-cpio");
AddMimeMapping(".cpp", "text/plain");
AddMimeMapping(".crd", "application/x-mscardfile");
AddMimeMapping(".crl", "application/pkix-crl");
AddMimeMapping(".crt", "application/x-x509-ca-cert");
AddMimeMapping(".csh", "application/x-csh");
AddMimeMapping(".css", "text/css");
AddMimeMapping(".csv", "application/octet-stream");
AddMimeMapping(".cur", "application/octet-stream");
AddMimeMapping(".dcr", "application/x-director");
AddMimeMapping(".deploy", "application/octet-stream");
AddMimeMapping(".der", "application/x-x509-ca-cert");
AddMimeMapping(".dib", "image/bmp");
AddMimeMapping(".dir", "application/x-director");
AddMimeMapping(".disco", "text/xml");
AddMimeMapping(".dll", "application/x-msdownload");
AddMimeMapping(".dll.config", "text/xml");
AddMimeMapping(".dlm", "text/dlm");
AddMimeMapping(".doc", "application/msword");
AddMimeMapping(".docm", "application/vnd.ms-word.document.macroEnabled.12");
AddMimeMapping(".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document");
AddMimeMapping(".dot", "application/msword");
AddMimeMapping(".dotm", "application/vnd.ms-word.template.macroEnabled.12");
AddMimeMapping(".dotx", "application/vnd.openxmlformats-officedocument.wordprocessingml.template");
AddMimeMapping(".dsp", "application/octet-stream");
AddMimeMapping(".dtd", "text/xml");
AddMimeMapping(".dvi", "application/x-dvi");
AddMimeMapping(".dwf", "drawing/x-dwf");
AddMimeMapping(".dwp", "application/octet-stream");
AddMimeMapping(".dxr", "application/x-director");
AddMimeMapping(".eml", "message/rfc822");
AddMimeMapping(".emz", "application/octet-stream");
AddMimeMapping(".eot", "application/octet-stream");
AddMimeMapping(".eps", "application/postscript");
AddMimeMapping(".etx", "text/x-setext");
AddMimeMapping(".evy", "application/envoy");
AddMimeMapping(".exe", "application/octet-stream");
AddMimeMapping(".exe.config", "text/xml");
AddMimeMapping(".fdf", "application/vnd.fdf");
AddMimeMapping(".fif", "application/fractals");
AddMimeMapping(".fla", "application/octet-stream");
AddMimeMapping(".flr", "x-world/x-vrml");
AddMimeMapping(".flv", "video/x-flv");
AddMimeMapping(".gif", "image/gif");
AddMimeMapping(".gtar", "application/x-gtar");
AddMimeMapping(".gz", "application/x-gzip");
AddMimeMapping(".h", "text/plain");
AddMimeMapping(".hdf", "application/x-hdf");
AddMimeMapping(".hdml", "text/x-hdml");
AddMimeMapping(".hhc", "application/x-oleobject");
AddMimeMapping(".hhk", "application/octet-stream");
AddMimeMapping(".hhp", "application/octet-stream");
AddMimeMapping(".hlp", "application/winhlp");
AddMimeMapping(".hqx", "application/mac-binhex40");
AddMimeMapping(".hta", "application/hta");
AddMimeMapping(".htc", "text/x-component");
AddMimeMapping(".htm", "text/html");
AddMimeMapping(".html", "text/html");
AddMimeMapping(".htt", "text/webviewhtml");
AddMimeMapping(".hxt", "text/html");
AddMimeMapping(".ico", "image/x-icon");
AddMimeMapping(".ics", "application/octet-stream");
AddMimeMapping(".ief", "image/ief");
AddMimeMapping(".iii", "application/x-iphone");
AddMimeMapping(".inf", "application/octet-stream");
AddMimeMapping(".ins", "application/x-internet-signup");
AddMimeMapping(".isp", "application/x-internet-signup");
AddMimeMapping(".IVF", "video/x-ivf");
AddMimeMapping(".jar", "application/java-archive");
AddMimeMapping(".java", "application/octet-stream");
AddMimeMapping(".jck", "application/liquidmotion");
AddMimeMapping(".jcz", "application/liquidmotion");
AddMimeMapping(".jfif", "image/pjpeg");
AddMimeMapping(".jpb", "application/octet-stream");
AddMimeMapping(".jpe", "image/jpeg");
AddMimeMapping(".jpeg", "image/jpeg");
AddMimeMapping(".jpg", "image/jpeg");
AddMimeMapping(".js", "application/x-javascript");
AddMimeMapping(".jsx", "text/jscript");
AddMimeMapping(".latex", "application/x-latex");
AddMimeMapping(".lit", "application/x-ms-reader");
AddMimeMapping(".lpk", "application/octet-stream");
AddMimeMapping(".lsf", "video/x-la-asf");
AddMimeMapping(".lsx", "video/x-la-asf");
AddMimeMapping(".lzh", "application/octet-stream");
AddMimeMapping(".m13", "application/x-msmediaview");
AddMimeMapping(".m14", "application/x-msmediaview");
AddMimeMapping(".m1v", "video/mpeg");
AddMimeMapping(".m3u", "audio/x-mpegurl");
AddMimeMapping(".man", "application/x-troff-man");
AddMimeMapping(".manifest", "application/x-ms-manifest");
AddMimeMapping(".map", "text/plain");
AddMimeMapping(".mdb", "application/x-msaccess");
AddMimeMapping(".mdp", "application/octet-stream");
AddMimeMapping(".me", "application/x-troff-me");
AddMimeMapping(".mht", "message/rfc822");
AddMimeMapping(".mhtml", "message/rfc822");
AddMimeMapping(".mid", "audio/mid");
AddMimeMapping(".midi", "audio/mid");
AddMimeMapping(".mix", "application/octet-stream");
AddMimeMapping(".mmf", "application/x-smaf");
AddMimeMapping(".mno", "text/xml");
AddMimeMapping(".mny", "application/x-msmoney");
AddMimeMapping(".mov", "video/quicktime");
AddMimeMapping(".movie", "video/x-sgi-movie");
AddMimeMapping(".mp2", "video/mpeg");
AddMimeMapping(".mp3", "audio/mpeg");
AddMimeMapping(".mpa", "video/mpeg");
AddMimeMapping(".mpe", "video/mpeg");
AddMimeMapping(".mpeg", "video/mpeg");
AddMimeMapping(".mpg", "video/mpeg");
AddMimeMapping(".mpp", "application/vnd.ms-project");
AddMimeMapping(".mpv2", "video/mpeg");
AddMimeMapping(".ms", "application/x-troff-ms");
AddMimeMapping(".msi", "application/octet-stream");
AddMimeMapping(".mso", "application/octet-stream");
AddMimeMapping(".mvb", "application/x-msmediaview");
AddMimeMapping(".mvc", "application/x-miva-compiled");
AddMimeMapping(".nc", "application/x-netcdf");
AddMimeMapping(".nsc", "video/x-ms-asf");
AddMimeMapping(".nws", "message/rfc822");
AddMimeMapping(".ocx", "application/octet-stream");
AddMimeMapping(".oda", "application/oda");
AddMimeMapping(".odc", "text/x-ms-odc");
AddMimeMapping(".ods", "application/oleobject");
AddMimeMapping(".one", "application/onenote");
AddMimeMapping(".onea", "application/onenote");
AddMimeMapping(".onetoc", "application/onenote");
AddMimeMapping(".onetoc2", "application/onenote");
AddMimeMapping(".onetmp", "application/onenote");
AddMimeMapping(".onepkg", "application/onenote");
AddMimeMapping(".osdx", "application/opensearchdescription+xml");
AddMimeMapping(".p10", "application/pkcs10");
AddMimeMapping(".p12", "application/x-pkcs12");
AddMimeMapping(".p7b", "application/x-pkcs7-certificates");
AddMimeMapping(".p7c", "application/pkcs7-mime");
AddMimeMapping(".p7m", "application/pkcs7-mime");
AddMimeMapping(".p7r", "application/x-pkcs7-certreqresp");
AddMimeMapping(".p7s", "application/pkcs7-signature");
AddMimeMapping(".pbm", "image/x-portable-bitmap");
AddMimeMapping(".pcx", "application/octet-stream");
AddMimeMapping(".pcz", "application/octet-stream");
AddMimeMapping(".pdf", "application/pdf");
AddMimeMapping(".pfb", "application/octet-stream");
AddMimeMapping(".pfm", "application/octet-stream");
AddMimeMapping(".pfx", "application/x-pkcs12");
AddMimeMapping(".pgm", "image/x-portable-graymap");
AddMimeMapping(".pko", "application/vnd.ms-pki.pko");
AddMimeMapping(".pma", "application/x-perfmon");
AddMimeMapping(".pmc", "application/x-perfmon");
AddMimeMapping(".pml", "application/x-perfmon");
AddMimeMapping(".pmr", "application/x-perfmon");
AddMimeMapping(".pmw", "application/x-perfmon");
AddMimeMapping(".png", "image/png");
AddMimeMapping(".pnm", "image/x-portable-anymap");
AddMimeMapping(".pnz", "image/png");
AddMimeMapping(".pot", "application/vnd.ms-powerpoint");
AddMimeMapping(".potm", "application/vnd.ms-powerpoint.template.macroEnabled.12");
AddMimeMapping(".potx", "application/vnd.openxmlformats-officedocument.presentationml.template");
AddMimeMapping(".ppam", "application/vnd.ms-powerpoint.addin.macroEnabled.12");
AddMimeMapping(".ppm", "image/x-portable-pixmap");
AddMimeMapping(".pps", "application/vnd.ms-powerpoint");
AddMimeMapping(".ppsm", "application/vnd.ms-powerpoint.slideshow.macroEnabled.12");
AddMimeMapping(".ppsx", "application/vnd.openxmlformats-officedocument.presentationml.slideshow");
AddMimeMapping(".ppt", "application/vnd.ms-powerpoint");
AddMimeMapping(".pptm", "application/vnd.ms-powerpoint.presentation.macroEnabled.12");
AddMimeMapping(".pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation");
AddMimeMapping(".prf", "application/pics-rules");
AddMimeMapping(".prm", "application/octet-stream");
AddMimeMapping(".prx", "application/octet-stream");
AddMimeMapping(".ps", "application/postscript");
AddMimeMapping(".psd", "application/octet-stream");
AddMimeMapping(".psm", "application/octet-stream");
AddMimeMapping(".psp", "application/octet-stream");
AddMimeMapping(".pub", "application/x-mspublisher");
AddMimeMapping(".qt", "video/quicktime");
AddMimeMapping(".qtl", "application/x-quicktimeplayer");
AddMimeMapping(".qxd", "application/octet-stream");
AddMimeMapping(".ra", "audio/x-pn-realaudio");
AddMimeMapping(".ram", "audio/x-pn-realaudio");
AddMimeMapping(".rar", "application/octet-stream");
AddMimeMapping(".ras", "image/x-cmu-raster");
AddMimeMapping(".rf", "image/vnd.rn-realflash");
AddMimeMapping(".rgb", "image/x-rgb");
AddMimeMapping(".rm", "application/vnd.rn-realmedia");
AddMimeMapping(".rmi", "audio/mid");
AddMimeMapping(".roff", "application/x-troff");
AddMimeMapping(".rpm", "audio/x-pn-realaudio-plugin");
AddMimeMapping(".rtf", "application/rtf");
AddMimeMapping(".rtx", "text/richtext");
AddMimeMapping(".scd", "application/x-msschedule");
AddMimeMapping(".sct", "text/scriptlet");
AddMimeMapping(".sea", "application/octet-stream");
AddMimeMapping(".setpay", "application/set-payment-initiation");
AddMimeMapping(".setreg", "application/set-registration-initiation");
AddMimeMapping(".sgml", "text/sgml");
AddMimeMapping(".sh", "application/x-sh");
AddMimeMapping(".shar", "application/x-shar");
AddMimeMapping(".sit", "application/x-stuffit");
AddMimeMapping(".sldm", "application/vnd.ms-powerpoint.slide.macroEnabled.12");
AddMimeMapping(".sldx", "application/vnd.openxmlformats-officedocument.presentationml.slide");
AddMimeMapping(".smd", "audio/x-smd");
AddMimeMapping(".smi", "application/octet-stream");
AddMimeMapping(".smx", "audio/x-smd");
AddMimeMapping(".smz", "audio/x-smd");
AddMimeMapping(".snd", "audio/basic");
AddMimeMapping(".snp", "application/octet-stream");
AddMimeMapping(".spc", "application/x-pkcs7-certificates");
AddMimeMapping(".spl", "application/futuresplash");
AddMimeMapping(".src", "application/x-wais-source");
AddMimeMapping(".ssm", "application/streamingmedia");
AddMimeMapping(".sst", "application/vnd.ms-pki.certstore");
AddMimeMapping(".stl", "application/vnd.ms-pki.stl");
AddMimeMapping(".sv4cpio", "application/x-sv4cpio");
AddMimeMapping(".sv4crc", "application/x-sv4crc");
AddMimeMapping(".swf", "application/x-shockwave-flash");
AddMimeMapping(".t", "application/x-troff");
AddMimeMapping(".tar", "application/x-tar");
AddMimeMapping(".tcl", "application/x-tcl");
AddMimeMapping(".tex", "application/x-tex");
AddMimeMapping(".texi", "application/x-texinfo");
AddMimeMapping(".texinfo", "application/x-texinfo");
AddMimeMapping(".tgz", "application/x-compressed");
AddMimeMapping(".thmx", "application/vnd.ms-officetheme");
AddMimeMapping(".thn", "application/octet-stream");
AddMimeMapping(".tif", "image/tiff");
AddMimeMapping(".tiff", "image/tiff");
AddMimeMapping(".toc", "application/octet-stream");
AddMimeMapping(".tr", "application/x-troff");
AddMimeMapping(".trm", "application/x-msterminal");
AddMimeMapping(".tsv", "text/tab-separated-values");
AddMimeMapping(".ttf", "application/octet-stream");
AddMimeMapping(".txt", "text/plain");
AddMimeMapping(".u32", "application/octet-stream");
AddMimeMapping(".uls", "text/iuls");
AddMimeMapping(".ustar", "application/x-ustar");
AddMimeMapping(".vbs", "text/vbscript");
AddMimeMapping(".vcf", "text/x-vcard");
AddMimeMapping(".vcs", "text/plain");
AddMimeMapping(".vdx", "application/vnd.ms-visio.viewer");
AddMimeMapping(".vml", "text/xml");
AddMimeMapping(".vsd", "application/vnd.visio");
AddMimeMapping(".vss", "application/vnd.visio");
AddMimeMapping(".vst", "application/vnd.visio");
AddMimeMapping(".vsto", "application/x-ms-vsto");
AddMimeMapping(".vsw", "application/vnd.visio");
AddMimeMapping(".vsx", "application/vnd.visio");
AddMimeMapping(".vtx", "application/vnd.visio");
AddMimeMapping(".wav", "audio/wav");
AddMimeMapping(".wax", "audio/x-ms-wax");
AddMimeMapping(".wbmp", "image/vnd.wap.wbmp");
AddMimeMapping(".wcm", "application/vnd.ms-works");
AddMimeMapping(".wdb", "application/vnd.ms-works");
AddMimeMapping(".wks", "application/vnd.ms-works");
AddMimeMapping(".wm", "video/x-ms-wm");
AddMimeMapping(".wma", "audio/x-ms-wma");
AddMimeMapping(".wmd", "application/x-ms-wmd");
AddMimeMapping(".wmf", "application/x-msmetafile");
AddMimeMapping(".wml", "text/vnd.wap.wml");
AddMimeMapping(".wmlc", "application/vnd.wap.wmlc");
AddMimeMapping(".wmls", "text/vnd.wap.wmlscript");
AddMimeMapping(".wmlsc", "application/vnd.wap.wmlscriptc");
AddMimeMapping(".wmp", "video/x-ms-wmp");
AddMimeMapping(".wmv", "video/x-ms-wmv");
AddMimeMapping(".wmx", "video/x-ms-wmx");
AddMimeMapping(".wmz", "application/x-ms-wmz");
AddMimeMapping(".wps", "application/vnd.ms-works");
AddMimeMapping(".wri", "application/x-mswrite");
AddMimeMapping(".wrl", "x-world/x-vrml");
AddMimeMapping(".wrz", "x-world/x-vrml");
AddMimeMapping(".wsdl", "text/xml");
AddMimeMapping(".wvx", "video/x-ms-wvx");
AddMimeMapping(".x", "application/directx");
AddMimeMapping(".xaf", "x-world/x-vrml");
AddMimeMapping(".xaml", "application/xaml+xml");
AddMimeMapping(".xap", "application/x-silverlight-app");
AddMimeMapping(".xbap", "application/x-ms-xbap");
AddMimeMapping(".xbm", "image/x-xbitmap");
AddMimeMapping(".xdr", "text/plain");
AddMimeMapping(".xla", "application/vnd.ms-excel");
AddMimeMapping(".xlam", "application/vnd.ms-excel.addin.macroEnabled.12");
AddMimeMapping(".xlc", "application/vnd.ms-excel");
AddMimeMapping(".xlm", "application/vnd.ms-excel");
AddMimeMapping(".xls", "application/vnd.ms-excel");
AddMimeMapping(".xlsb", "application/vnd.ms-excel.sheet.binary.macroEnabled.12");
AddMimeMapping(".xlsm", "application/vnd.ms-excel.sheet.macroEnabled.12");
AddMimeMapping(".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
AddMimeMapping(".xlt", "application/vnd.ms-excel");
AddMimeMapping(".xltm", "application/vnd.ms-excel.template.macroEnabled.12");
AddMimeMapping(".xltx", "application/vnd.openxmlformats-officedocument.spreadsheetml.template");
AddMimeMapping(".xlw", "application/vnd.ms-excel");
AddMimeMapping(".xml", "text/xml");
AddMimeMapping(".xof", "x-world/x-vrml");
AddMimeMapping(".xpm", "image/x-xpixmap");
AddMimeMapping(".xps", "application/vnd.ms-xpsdocument");
AddMimeMapping(".xsd", "text/xml");
AddMimeMapping(".xsf", "text/xml");
AddMimeMapping(".xsl", "text/xml");
AddMimeMapping(".xslt", "text/xml");
AddMimeMapping(".xsn", "application/octet-stream");
AddMimeMapping(".xtp", "application/octet-stream");
AddMimeMapping(".xwd", "image/x-xwindowdump");
AddMimeMapping(".z", "application/x-compress");
AddMimeMapping(".zip", "application/x-zip-compressed");
}
}
支付宝扫码打赏
微信打赏
