C# Mime 类型类答案

【问题标题】：C# Mime Types classC# Mime 类型类
【发布时间】：2018-06-01 20:22:28
【问题描述】：

我想在我的代码中保存一个 Mime 类型。现在我习惯这样做：

string mYMimeType = "text/plain";

有没有办法将它保存在（已经存在的）标准的专用类中？比如……

Http.MimeTypes myMimeType = Http.MimeTypes.TextPlain;

【问题讨论】：

标签： c# .net mime-types

【解决方案1】：

你可以利用MediaTypeNames类存在于System.Net.Mime命名空间。

下面是.net类可以帮助你，你不必自己创建它。

namespace System.Net.Mime
{
    // Summary:
    //     Specifies the media type information for an e-mail message attachment.
    public static class MediaTypeNames
    {

        // Summary:
        //     Specifies the kind of application data in an e-mail message attachment.
        public static class Application
        {
            // Summary:
            //     Specifies that the System.Net.Mime.MediaTypeNames.Application data is not
            //     interpreted.
            public const string Octet = "application/octet-stream";
            //
            // Summary:
            //     Specifies that the System.Net.Mime.MediaTypeNames.Application data is in
            //     Portable Document Format (PDF).
            public const string Pdf = "application/pdf";
            //
            // Summary:
            //     Specifies that the System.Net.Mime.MediaTypeNames.Application data is in
            //     Rich Text Format (RTF).
            public const string Rtf = "application/rtf";
            //
            // Summary:
            //     Specifies that the System.Net.Mime.MediaTypeNames.Application data is a SOAP
            //     document.
            public const string Soap = "application/soap+xml";
            //
            // Summary:
            //     Specifies that the System.Net.Mime.MediaTypeNames.Application data is compressed.
            public const string Zip = "application/zip";
        }

        // Summary:
        //     Specifies the type of image data in an e-mail message attachment.
        public static class Image
        {
            // Summary:
            //     Specifies that the System.Net.Mime.MediaTypeNames.Image data is in Graphics
            //     Interchange Format (GIF).
            public const string Gif = "image/gif";
            //
            // Summary:
            //     Specifies that the System.Net.Mime.MediaTypeNames.Image data is in Joint
            //     Photographic Experts Group (JPEG) format.
            public const string Jpeg = "image/jpeg";
            //
            // Summary:
            //     Specifies that the System.Net.Mime.MediaTypeNames.Image data is in Tagged
            //     Image File Format (TIFF).
            public const string Tiff = "image/tiff";
        }

        // Summary:
        //     Specifies the type of text data in an e-mail message attachment.
        public static class Text
        {
            // Summary:
            //     Specifies that the System.Net.Mime.MediaTypeNames.Text data is in HTML format.
            public const string Html = "text/html";
            //
            // Summary:
            //     Specifies that the System.Net.Mime.MediaTypeNames.Text data is in plain text
            //     format.
            public const string Plain = "text/plain";
            //
            // Summary:
            //     Specifies that the System.Net.Mime.MediaTypeNames.Text data is in Rich Text
            //     Format (RTF).
            public const string RichText = "text/richtext";
            //
            // Summary:
            //     Specifies that the System.Net.Mime.MediaTypeNames.Text data is in XML format.
            public const string Xml = "text/xml";
        }
    }
}

【讨论】：

为什么像 .net 这样的标准没有所有的媒体类型，而只有少数？我不明白 :-) 不过，谢谢你的回复
他们甚至没有text/json 或application/json，哇。 ?
哦，这不是真的。由于 dotnet core 2.1 MediaTypeNames.Application.Json 已被定义。

【解决方案2】：

您可以使用方法通过文件扩展名MimeTypeMapper.GetMimeType(".xlsx")获取mime类型下面是一个实现示例：

public static class MimeTypeMapper
{
    private static readonly IDictionary<string, string> _mappings =
        new Dictionary<string, string>(StringComparer.InvariantCultureIgnoreCase)
        {
            {".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"},
            {".zip", "application/x-zip-compressed"},
        };

    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";
    }
}

【讨论】：