lionsoul2014/ip2region · error · ArgumentNullException

dbPath

Error message

dbPath

What it means

Standard .NET ArgumentNullException thrown by GetVersionAsync when the dbPath argument is null or empty: a required argument guard, not a file or format problem. The named parameter identifies dbPath as the faulting input.

Source

Thrown at binding/csharp/IP2Region.Net/XDB/Util.cs:40

        var address = IPAddress.Parse(ipAddress);
        return IpAddressToUInt32(address);
    }

    public static uint IpAddressToUInt32(IPAddress ipAddress)
    {
        byte[] bytes = ipAddress.GetAddressBytes();
        Array.Reverse(bytes);
        return MemoryMarshal.Read<uint>(bytes);
    }

    public static uint GetMidIp(uint x, uint y)
        => (x & y) + ((x ^ y) >> 1);

    public static async Task<XdbVersion> GetVersionAsync(string dbPath, CancellationToken token = default)
    {
        if (string.IsNullOrEmpty(dbPath))
        {
            throw new ArgumentNullException(nameof(dbPath));
        }

        if (!File.Exists(dbPath))
        {
            throw new FileNotFoundException("xdb file not found.", dbPath);
        }

        using var reader = File.OpenRead(dbPath);
        return await GetVersionAsync(reader, token);
    }

    internal static async Task<XdbVersion> GetVersionAsync(FileStream reader, CancellationToken token = default)
    {
        XdbVersion ret = default;
        var buffer = ArrayPool<byte>.Shared.Rent(256);

        try
        {

View on GitHub (pinned to c1a1fc7d59)

Solutions

1. Pass a non-empty xdb file path to GetVersionAsync
2. Check configuration loading so the dbPath setting is never silently null
3. Guard callers with string.IsNullOrWhiteSpace before invoking the API

When it happens

Trigger: Thrown at binding/csharp/IP2Region.Net/XDB/Util.cs:40 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of lionsoul2014/ip2region@c1a1fc7d59 (2026-09-02). Data as JSON: /api/errors/e230fcc9a69116c8. Report an issue: GitHub.