C# 比较版本标识符

Compare Version Identifiers

提问by Nick

Here is my code, which takes two version identifiers in the form "1, 5, 0, 4" or "1.5.0.4" and determines which is the newer version.

这是我的代码，它采用“1、5、0、4”或“1.5.0.4”形式的两个版本标识符，并确定哪个是较新的版本。

Suggestions or improvements, please!

建议或改进，请！

    /// <summary>
    /// Compares two specified version strings and returns an integer that 
    /// indicates their relationship to one another in the sort order.
    /// </summary>
    /// <param name="strA">the first version</param>
    /// <param name="strB">the second version</param>
    /// <returns>less than zero if strA is less than strB, equal to zero if
    /// strA equals strB, and greater than zero if strA is greater than strB</returns>
    public static int CompareVersions(string strA, string strB)
    {
        char[] splitTokens = new char[] {'.', ','};
        string[] strAsplit = strA.Split(splitTokens, StringSplitOptions.RemoveEmptyEntries);
        string[] strBsplit = strB.Split(splitTokens, StringSplitOptions.RemoveEmptyEntries);
        int[] versionA = new int[4];
        int[] versionB = new int[4];

        for (int i = 0; i < 4; i++)
        {
            versionA[i] = Convert.ToInt32(strAsplit[i]);
            versionB[i] = Convert.ToInt32(strBsplit[i]);
        }

        // now that we have parsed the input strings, compare them
        return RecursiveCompareArrays(versionA, versionB, 0);
    }

    /// <summary>
    /// Recursive function for comparing arrays, 0-index is highest priority
    /// </summary>
    private static int RecursiveCompareArrays(int[] versionA, int[] versionB, int idx)
    {
        if (versionA[idx] < versionB[idx])
            return -1;
        else if (versionA[idx] > versionB[idx])
            return 1;
        else
        {
            Debug.Assert(versionA[idx] == versionB[idx]);
            if (idx == versionA.Length - 1)
                return 0;
            else
                return RecursiveCompareArrays(versionA, versionB, idx + 1);
        }
    }

---

---

@ Darren Kopp:

@达伦科普：

The version class does not handle versions of the format 1.0.0.5.

版本类不处理 1.0.0.5 格式的版本。

采纳答案by Antti Kissaniemi

The System.Versionclass does not support versions with commas in it, so the solution presented by Darren Koppis not sufficient.

该System.Version类不支持在它逗号版本，因此所提出的解决方案达伦·柯普是不够的。

Here is a version that is as simple as possible (but no simpler).

这是一个尽可能简单的版本（但并不简单）。

It uses System.Versionbut achieves compatibility with version numbers like "1, 2, 3, 4" by doing a search-replace before comparing.

它使用System.Version但通过在比较之前进行搜索替换来实现与“1、2、3、4”等版本号的兼容性。

    /// <summary>
    /// Compare versions of form "1,2,3,4" or "1.2.3.4". Throws FormatException
    /// in case of invalid version.
    /// </summary>
    /// <param name="strA">the first version</param>
    /// <param name="strB">the second version</param>
    /// <returns>less than zero if strA is less than strB, equal to zero if
    /// strA equals strB, and greater than zero if strA is greater than strB</returns>
    public static int CompareVersions(String strA, String strB)
    {
        Version vA = new Version(strA.Replace(",", "."));
        Version vB = new Version(strB.Replace(",", "."));

        return vA.CompareTo(vB);
    }

The code has been tested with:

代码已经过测试：

    static void Main(string[] args)
    {
        Test("1.0.0.0", "1.0.0.1", -1);
        Test("1.0.0.1", "1.0.0.0", 1);
        Test("1.0.0.0", "1.0.0.0", 0);
        Test("1, 0.0.0", "1.0.0.0", 0);
        Test("9, 5, 1, 44", "3.4.5.6", 1);
        Test("1, 5, 1, 44", "3.4.5.6", -1);
        Test("6,5,4,3", "6.5.4.3", 0);

        try
        {
            CompareVersions("2, 3, 4 - 4", "1,2,3,4");
            Console.WriteLine("Exception should have been thrown");
        }
        catch (FormatException e)
        {
            Console.WriteLine("Got exception as expected.");
        }

        Console.ReadLine();
    }

    private static void Test(string lhs, string rhs, int expected)
    {
        int result = CompareVersions(lhs, rhs);
        Console.WriteLine("Test(\"" + lhs + "\", \"" + rhs + "\", " + expected +
            (result.Equals(expected) ? " succeeded." : " failed."));
    }

回答by Craig

Well, since you only have a four element array you may just want ot unroll the recursion to save time. Passing arrays as arguments will eat up memory and leave a mess for the GC to clean up later.

好吧，由于您只有一个四元素数组，您可能只想展开递归以节省时间。将数组作为参数传递会占用内存，并为 GC 稍后清理留下一团糟。

回答by Darren Kopp

Use the Versionclass.

使用版本类。

Version a = new Version("1.0.0.0");
Version b = new Version("2.0.0.0");

Console.WriteLine(string.Format("Newer: {0}", (a > b) ? "a" : "b"));
// prints b

回答by Adam Haile

If you can assume that each place in the version string will only be one number (or at least the last 3, you can just remove the commas or periods and compare...which would be a lot faster...not as robust, but you don't always need that.

如果您可以假设版本字符串中的每个位置都只有一个数字（或至少是最后 3 个，您可以删除逗号或句点并进行比较……这会快得多……不那么健壮，但你并不总是需要那个。

public static int CompareVersions(string strA, string strB)
{
    char[] splitTokens = new char[] {'.', ','};
    string[] strAsplit = strA.Split(splitTokens, StringSplitOptions.RemoveEmptyEntries);
    string[] strBsplit = strB.Split(splitTokens, StringSplitOptions.RemoveEmptyEntries);
    int versionA = 0;
    int versionB = 0;
    string vA = string.Empty;
    string vB = string.Empty;

    for (int i = 0; i < 4; i++)
    {
        vA += strAsplit[i];
        vB += strBsplit[i];
        versionA[i] = Convert.ToInt32(strAsplit[i]);
        versionB[i] = Convert.ToInt32(strBsplit[i]);
    }

    versionA = Convert.ToInt32(vA);
    versionB = Convert.ToInt32(vB);

    if(vA > vB)
       return 1;
    else if(vA < vB)
       return -1;
    else
       return 0;  //they are equal
}

And yes, I'm also assuming 4 version places here...

是的，我还假设这里有 4 个版本......