Accessing .NET code from Xojo (C# custom DLL)

Targets Windows
21

To get a string out of my dll I used " out string response" however this doesn’t work in Xojo, it does work in a VS form

To be honest, I haven’t really tried, I came to Xojo to escape C# and Mono on Mac/Linux

It’ll be good to keep watching to see if you find a solution though!!

22

Here is some of the code I was playing with this morning.

Imports System
Imports System.Runtime.InteropServices


Namespace VBStrings

    <Guid("89439AD1-756F-4f9c-BFB4-18236F63251E"), _
    InterfaceType(ComInterfaceType.InterfaceIsIDispatch)> _
    Public Interface _VBStrings
        <DispId(1)> Function GetDaysDiff(d1 As String, d2 As String) As Integer
        <DispId(2)> Function PadXojoString(source As String, padChar As String, padCount As Integer) As String
        <DispId(3)> Function AddDays(sDate As String, iDaysToAdd As Integer) As String
    End Interface

    <Guid("1376DE24-CC2D-46cb-8BF0-887A9CAF3014"), _
     ClassInterface(ClassInterfaceType.None), _
     ProgId("hdXojoStrings")> Public Class VBStrings
        Implements _VBStrings

        Public VBStrings()

        Public Function GetDaysDiff(sDateStart As String, sDateEnd As String) As Integer Implements _VBStrings.GetDaysDiff
            Dim diff As Integer = 0
            Dim d1 As Date
            Dim d2 As Date

            Try
                d1 = CDate(sDateStart)
            Catch ex As Exception
                diff = -1
            End Try

            Try
                d2 = CDate(sDateEnd)
            Catch ex As Exception
                diff = -1
            End Try

            If diff = 0 Then
                diff = DateDiff(DateInterval.Day, d1, d2)
            End If

            Return diff
        End Function

        Public Function PadXojoString(source As String, pChar As String, pCount As Integer) As String Implements _VBStrings.PadXojoString

            Return source.PadLeft(pCount, pChar)

        End Function

        Public Function AddDays(sDate As String, iDaysToAdd As Integer) As String Implements _VBStrings.AddDays
            Dim results As String = ""
            Dim mDate As Date = Nothing

            Try
                mDate = CDate(sDate)
            Catch ex As Exception
                results = ex.Message
            End Try

            If results = "" Then
                mDate = mDate.AddDays(iDaysToAdd)
                results = mDate.ToShortDateString
            End If

            Return results
        End Function
    End Class

End Namespace
23

[quote=130527:@Johnny Harris]Here is some of the code I was playing with this morning.
[/quote]

Great. I was able to modify my project and now can pass strings back and forth. I do not know what happened before. Maybe I ran into the busy DLL file or something.

The important part is now I can tap into some of the .NET functions inaccessible to Xojo Win32.

Thank you.

24

Hi Johnny
I am interesting in that code to use DateDiff from VB or c#, that code is VB.net or c#.

So how i use the code in xojo ?

thanks

25

Why, there’s already a DateInterval object:

[code]Function datediff(fromdate as DateTime, toDate as Datetime) as DateInterval

var diff as DateInterval = new DateInterval
diff = toDate - fromDate

return diff

End Function
[/code]

26

ok
thanks