使用.NET,如何根据文件签名而不是扩展名找到文件的mime类型

dotnet add package System.IO.Compression

using System.IO;
using System.IO.Compression;

public static string GetMimeTypeFromSignature(string filePath)
{
    // 读取文件的前几个字节以获取文件签名
    byte[] fileHeader = new byte[2];
    using (FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read))
    {
        fileStream.Read(fileHeader, 0, 2);
    }

    // 根据文件签名判断MIME类型
    string mimeType = "application/octet-stream"; // 默认MIME类型
    if (fileHeader[0] == 0xFF && fileHeader[1] == 0xD8)
    {
        mimeType = "image/jpeg";
    }
    else if (fileHeader[0] == 0x89 && fileHeader[1] == 0x50)
    {
        mimeType = "image/png";
    }
    else if (fileHeader[0] == 0x47 && fileHeader[1] == 0x49)
    {
        mimeType = "image/gif";
    }
    else if (fileHeader[0] == 0x50 && fileHeader[1] == 0x4B)
    {
        mimeType = "application/zip";
    }
    else if (fileHeader[0] == 0x3C && fileHeader[1] == 0x3F)
    {
        mimeType = "application/xml";
    }
    // 可以根据需要添加更多的文件签名和MIME类型的对应关系

    return mimeType;
}

string filePath = "path/to/your/file";
string mimeType = GetMimeTypeFromSignature(filePath);
Console.WriteLine($"The MIME type of the file is: {mimeType}");