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C# Migration Highlights

Software migration is a complex process. During a transformation one must consider multiple aspects of the output code (Equivalence, Complexity, Readability, Maintainability, etc.) In this blog, I wanted to highlight some of our VB6 to C# (.NET) transformations.

File IO

Section titled “File IO”
BeforeAfter
If Dir(LogPath, vbDirectory) <> "" Then
if (System.IO.Directory.Exists(LogPath))
If Dir(FName) <> "" Then
if (System.IO.File.Exists(FName))

DateDiff Method

Section titled “DateDiff Method”
BeforeAfter
i = DateDiff("YYYY", d2, d)
    i = DateDiff("M", d2, d)
    i = DateDiff("D", d2, d)
    i = DateDiff("H", d2, d)
    i = DateDiff("N", d2, d)
    i = DateDiff("S", d2, d)
i = (d.Year - d2.Year);
         i = ((d.Month + (d.Year * 12)) - (d2.Month + (d2.Year * 12)));
         i = ((int)d.Date.Subtract(d2.Date).TotalDays);
         i = ((int)d.Subtract(d2).TotalHours);
         i = ((int)d.Subtract(d2).TotalMinutes);
         i = ((int)d.Subtract(d2).TotalSeconds);

MsgBox Method

Section titled “MsgBox Method”
BeforeAfter
'MsgBox with message and title only
        i = MsgBox("a message box test", , "title")
        If MsgBox("a message box test", , "title") Then
        End If
// MsgBox with message and title only
            i = MessageBox.Show("a message box test","title",MessageBoxButtons.OK);
            if (MessageBox.Show("a message box test","title",MessageBoxButtons.OK) == DialogResult.Yes)
            {
            }
i = MsgBox("Save File Before Closing ?", 51)
i = MessageBox.Show("Save File Before Closing ?","",MessageBoxButtons.YesNoCancel,MessageBoxIcon.Exclamation);
Call MsgBox("a message box test", vbCritical Or _
            vbYesNoCancel Or _
            vbAbortRetryIgnore Or _
            vbApplicationModal Or _
            vbDefaultButton2 Or _
            vbQuestion, "title")
MessageBox.Show("a message box test","title",MessageBoxButtons.YesNoCancel |
                MessageBoxButtons.AbortRetryIgnore,
                MessageBoxIcon.Error |
                MessageBoxIcon.Question,
                MessageBoxDefaultButton.Button2,
                MessageBoxOptions.ServiceNotification);

Like Statement

Section titled “Like Statement”
BeforeAfter
'Tests copied from http://msdn.microsoft.com/en-us/library/swf8kaxw.aspx


    ' The following statement returns True (does "F" satisfy "F"?)
    wBA "Like", "'F' Like 'F'", "F" Like "F"
    '
    ' The following statement returns False for Option Compare Binary
    '    and True for Option Compare Text (does "F" satisfy "f"?)
    wBA "Like", "'F' Like 'f'", "F" Like "f"
    '
    ' The following statement returns False (does "F" satisfy "FFF"?)
    wBA "Like", "'F' Like 'FFF'", "F" Like "FFF"
    '
    ' The following statement returns True (does "aBBBa" have an "a" at the
    '    beginning, an "a" at the end, and any number of characters in
    '    between?)
    wBA "Like", "'aBBBa' Like 'a*a'", "aBBBa" Like "a*a"
    '
    ' The following statement returns True (does "F" occur in the set of
    '    characters from "A" through "Z"?)
    wBA "Like", "'F' Like '[A-Z]'", "F" Like "[A-Z]"
    '
    ' The following statement returns False (does "F" NOT occur in the
    '    set of characters from "A" through "Z"?)
    wBA "Like", "'F' Like '[!A-Z]'", "F" Like "[!A-Z]"
    '
    ' The following statement returns True (does "a2a" begin and end with
    '    an "a" and have any single-digit number in between?)
    wBA "Like", "'a2a' Like 'a#a'", "a2a" Like "a#a"
    '
    ' The following statement returns True (does "aM5b" begin with an "a",
    '    followed by any character from the set "L" through "P", followed
    '    by any single-digit number, and end with any character NOT in
    '    the character set "c" through "e"?)
    wBA "Like", "'aM5b' Like 'a[L-P]#[!c-e]'", "aM5b" Like "a[L-P]#[!c-e]"
    '
    ' The following statement returns True (does "BAT123khg" begin with a
    '    "B", followed by any single character, followed by a "T", and end
    '    with zero or more characters of any type?)
    wBA "Like", "'BAT123khg' Like 'B?T*'", "BAT123khg" Like "B?T*"
    '
    ' The following statement returns False (does "CAT123khg"?) begin with
    '    a "B", followed by any single character, followed by a "T", and
    '    end with zero or more characters of any type?)
    wBA "Like", "'CAT123khg' Like 'B?T*'", "CAT123khg" Like "B?T*"
// Tests copied from http://msdn.microsoft.com/en-us/library/swf8kaxw.aspx
         //
         //  The following statement returns True (does "F" satisfy "F"?)
         wBA("Like","'F' Like 'F'",Regex.IsMatch("F","F").ToString());
         //
         //  The following statement returns False for Option Compare Binary
         //     and True for Option Compare Text (does "F" satisfy "f"?)
         wBA("Like","'F' Like 'f'",Regex.IsMatch("F","f").ToString());
         //
         //  The following statement returns False (does "F" satisfy "FFF"?)
         wBA("Like","'F' Like 'FFF'",Regex.IsMatch("F","FFF").ToString());
         //
         //  The following statement returns True (does "aBBBa" have an "a" at the
         //     beginning, an "a" at the end, and any number of characters in
         //     between?)
         wBA("Like","'aBBBa' Like 'a*a'",Regex.IsMatch("aBBBa","a.*a").ToString());
         //
         //  The following statement returns True (does "F" occur in the set of
         //     characters from "A" through "Z"?)
         wBA("Like","'F' Like '[A-Z]'",Regex.IsMatch("F","[A-Z]").ToString());
         //
         //  The following statement returns False (does "F" NOT occur in the
         //     set of characters from "A" through "Z"?)
         wBA("Like","'F' Like '[!A-Z]'",Regex.IsMatch("F","[^A-Z]").ToString());
         //
         //  The following statement returns True (does "a2a" begin and end with
         //     an "a" and have any single-digit number in between?)
         wBA("Like","'a2a' Like 'a#a'",Regex.IsMatch("a2a","a\\da").ToString());
         //
         //  The following statement returns True (does "aM5b" begin with an "a",
         //     followed by any character from the set "L" through "P", followed
         //     by any single-digit number, and end with any character NOT in
         //     the character set "c" through "e"?)
         wBA("Like","'aM5b' Like 'a[L-P]#[!c-e]'",Regex.IsMatch("aM5b","a[L-P]\\d[^c-e]").ToString());
         //
         //  The following statement returns True (does "BAT123khg" begin with a
         //     "B", followed by any single character, followed by a "T", and end
         //     with zero or more characters of any type?)
         wBA("Like","'BAT123khg' Like 'B?T*'",Regex.IsMatch("BAT123khg","B.?T.*").ToString());
         //
         //  The following statement returns False (does "CAT123khg"?) begin with
         //     a "B", followed by any single character, followed by a "T", and
         //     end with zero or more characters of any type?)
         wBA("Like","'CAT123khg' Like 'B?T*'",Regex.IsMatch("CAT123khg","B.?T.*").ToString());

FormatDateTime Method

Section titled “FormatDateTime Method”
BeforeAfter
str = FormatDateTime(d, vbGeneralDate)
    str = FormatDateTime(d, vbLongDate)
    str = FormatDateTime(d, vbShortDate)
    str = FormatDateTime(d, vbLongTime)
    str = FormatDateTime(d, vbShortTime)
str = d.ToString();
         str = d.ToLongDateString();
         str = d.ToShortDateString();
         str = d.ToLongTimeString();
         str = d.ToString("HH:mm");