system.version超过3个小数点C＃

Question

I am currently receiving the following error - "Version string portion was too short or too long"

When using this statement -

records = records.OrderBy(r => new Version(r.RefNo)).ToList();

To order a list of string's called RefNo. It fails on 25.1.2.1.2 so i assume it is because it has four decimal points? as it works ok with 3....

Is the max four deciaml points for system.version?

Thanks

Answer 1

A Version can only have 4 parts:

major, minor, build, and revision, in that order, and all separated by periods.

That's why your approach fails. You could create an extension-method which handles this case, fe:

public static Version TryParseVersion(this string versionString)
{
    if (string.IsNullOrEmpty(versionString))
        return null;

    String[] tokens = versionString.Split('.');
    if (tokens.Length < 2 || !tokens.All(t => t.All(char.IsDigit)))
        return null;

    if (tokens.Length > 4)
    {
        int maxVersionLength = tokens.Skip(4).Max(t => t.Length);
        string normalizedRest = string.Concat(tokens.Skip(4).Select(t => t.PadLeft(maxVersionLength, '0')));
        tokens[3] = $"{tokens[3].PadLeft(maxVersionLength, '0')}{normalizedRest}";
        Array.Resize(ref tokens, 4);
    }

    versionString = string.Join(".", tokens);
    bool valid = Version.TryParse(versionString, out Version v);
    return valid ? v : null;
}

Now you can use it in this way:

records = records
   .OrderBy(r => r.RefNo.TryParseVersion())
   .ToList();

With your sample this new version string will be parsed(successfully): 25.1.2.12

Answer 2

See MSDN

Costructor public Version(string version)

A string containing the major, minor, build, and revision numbers, where each number is delimited with a period character ('.').

Makes a total of 4 numbers.

Means the string is limited to 4 numbers, 5 lead to an error.

Also the costructors with int 's as parameters only support 1 to 4 parameters.

Answer 3

sorry for the late reply but here is the finished extension method i used with a couple of alterations -

public static Version ParseRefNo(this string refNoString)
        {
            if (string.IsNullOrEmpty(refNoString))
                return null;

            String[] tokens = refNoString.Split('.');
            if (tokens.Length < 2 || !tokens.All(t => t.All(char.IsDigit)))
                return null;

            if (tokens.Length > 4)
            {
                int maxVersionLength = tokens.Skip(4).Max(t => t.Length);
                string normalizedRest = string.Concat(tokens.Skip(4).Select(t => t.PadLeft(maxVersionLength, '0')));
                tokens[3] = $"{tokens[3].PadLeft(maxVersionLength, '0')}{normalizedRest}";
                Array.Resize(ref tokens, 4);
            }

            refNoString = string.Join(".", tokens);
            Version v = null;
            bool valid = Version.TryParse(refNoString, out v);
            return valid ? v : null;
        }