How to convert string to version in .net 3.5?

Question

I want to compare the software version created in 3.5 with the older one. If I try to compare the version in 4.0, then it is easy using Version.Parse , but in an earlier version this tool is not. I tried to compare it using string comparison, but still could not get the desired result, because string comparison does not allow me to compare with a small version or a major version. Thanks in advance.

Answer 1

I had a similar problem - I had to analyze and sort the string numbers so that they could be displayed to the user in descending order. I ended up writing my own class to wrap parts of the build number and implemented IComparable for sorting. In addition, as a result, more and fewer operators were overloaded, as well as the Equals method. I think it has most of the functionality of the Version class, with the exception of MajorRevision and MinorRevision, which I have never used.

In fact, you can probably rename it to “Version” and use it just like you did with the “real” class.

Here is the code:

 public class BuildNumber : IComparable { public int Major { get; private set; } public int Minor { get; private set; } public int Build { get; private set; } public int Revision { get; private set; } private BuildNumber() { } public static bool TryParse(string input, out BuildNumber buildNumber) { try { buildNumber = Parse(input); return true; } catch { buildNumber = null; return false; } } /// <summary> /// Parses a build number string into a BuildNumber class /// </summary> /// <param name="buildNumber">The build number string to parse</param> /// <returns>A new BuildNumber class set from the buildNumber string</returns> /// <exception cref="ArgumentException">Thrown if there are less than 2 or /// more than 4 version parts to the build number</exception> /// <exception cref="FormatException">Thrown if string cannot be parsed /// to a series of integers</exception> /// <exception cref="ArgumentOutOfRangeException">Thrown if any version /// integer is less than zero</exception> public static BuildNumber Parse(string buildNumber) { if (buildNumber == null) throw new ArgumentNullException("buildNumber"); var versions = buildNumber .Split(new[] {'.'}, StringSplitOptions.RemoveEmptyEntries) .Select(v => v.Trim()) .ToList(); if (versions.Count < 2) { throw new ArgumentException("BuildNumber string was too short"); } if (versions.Count > 4) { throw new ArgumentException("BuildNumber string was too long"); } return new BuildNumber { Major = ParseVersion(versions[0]), Minor = ParseVersion(versions[1]), Build = versions.Count > 2 ? ParseVersion(versions[2]) : -1, Revision = versions.Count > 3 ? ParseVersion(versions[3]) : -1 }; } private static int ParseVersion(string input) { int version; if (!int.TryParse(input, out version)) { throw new FormatException( "buildNumber string was not in a correct format"); } if (version < 0) { throw new ArgumentOutOfRangeException( "buildNumber", "Versions must be greater than or equal to zero"); } return version; } public override string ToString() { return string.Format("{0}.{1}{2}{3}", Major, Minor, Build < 0 ? "" : "." + Build, Revision < 0 ? "" : "." + Revision); } public int CompareTo(object obj) { if (obj == null) return 1; var buildNumber = obj as BuildNumber; if (buildNumber == null) return 1; if (ReferenceEquals(this, buildNumber)) return 0; return (Major == buildNumber.Major) ? (Minor == buildNumber.Minor) ? (Build == buildNumber.Build) ? Revision.CompareTo(buildNumber.Revision) : Build.CompareTo(buildNumber.Build) : Minor.CompareTo(buildNumber.Minor) : Major.CompareTo(buildNumber.Major); } public static bool operator >(BuildNumber first, BuildNumber second) { return (first.CompareTo(second) > 0); } public static bool operator <(BuildNumber first, BuildNumber second) { return (first.CompareTo(second) < 0); } public override bool Equals(object obj) { return (CompareTo(obj) == 0); } public override int GetHashCode() { unchecked { var hash = 17; hash = hash * 23 + Major.GetHashCode(); hash = hash * 23 + Minor.GetHashCode(); hash = hash * 23 + Build.GetHashCode(); hash = hash * 23 + Revision.GetHashCode(); return hash; } } } 

Answer 2

Forgive me if I missed something, but cannot use the constructor of the version object, passing your version:

http://msdn.microsoft.com/en-us/library/y0hf9t2e%28v=vs.90%29.aspx?cs-save-lang=1&cs-lang=csharp#code-snippet-1

 string str = "0.1.2.3"; Version v = new Version(str); 

Answer 3

You can always try to decompile the class of the version of .NET 4.0 - you may be lucky that it just works in .NET 3.5.

Otherwise, you should look into string delimiters or regular expressions.

Answer 4

It looks like you are asking how to get versions of any local .NET installations. There is an article on MSDN about this: http://msdn.microsoft.com/en-us/library/hh925568%28v=vs.110%29.aspx .

They include the following function:

 private static void GetVersionFromRegistry() { // Opens the registry key for the .NET Framework entry. using (RegistryKey ndpKey = RegistryKey.OpenRemoteBaseKey(RegistryHive.LocalMachine, ""). OpenSubKey(@"SOFTWARE\Microsoft\NET Framework Setup\NDP\")) { // As an alternative, if you know the computers you will query are running .NET Framework 4.5 // or later, you can use: // using (RegistryKey ndpKey = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, // RegistryView.Registry32).OpenSubKey(@"SOFTWARE\Microsoft\NET Framework Setup\NDP\")) foreach (string versionKeyName in ndpKey.GetSubKeyNames()) { if (versionKeyName.StartsWith("v")) { RegistryKey versionKey = ndpKey.OpenSubKey(versionKeyName); string name = (string)versionKey.GetValue("Version", ""); string sp = versionKey.GetValue("SP", "").ToString(); string install = versionKey.GetValue("Install", "").ToString(); if (install == "") //no install info, must be later. Console.WriteLine(versionKeyName + " " + name); else { if (sp != "" && install == "1") { Console.WriteLine(versionKeyName + " " + name + " SP" + sp); } } if (name != "") { continue; } foreach (string subKeyName in versionKey.GetSubKeyNames()) { RegistryKey subKey = versionKey.OpenSubKey(subKeyName); name = (string)subKey.GetValue("Version", ""); if (name != "") sp = subKey.GetValue("SP", "").ToString(); install = subKey.GetValue("Install", "").ToString(); if (install == "") //no install info, must be later. Console.WriteLine(versionKeyName + " " + name); else { if (sp != "" && install == "1") { Console.WriteLine(" " + subKeyName + " " + name + " SP" + sp); } else if (install == "1") { Console.WriteLine(" " + subKeyName + " " + name); } } } } } } }