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I'm trying to create a class which behaves like a Double only allows values within a certain range.
One of the goals is to have it behave as a normal Double, i.e.: being able to assign Double values to it and pass it to functions taking a Double value.
Public Class RDouble
Public Sub New(ByVal D As Double, Optional ByVal Min As Double = 0, Optional ByVal Max As Double = 100)
_MinValue = Min
_MaxValue = Max
_dValue = D
If _dValue < _MinValue Then
_dValue = _MinValue
ElseIf _dValue > _MaxValue Then
_dValue = _MaxValue
End If
End Sub
Public _MinValue As Double
Private _MaxValue As Double
Private _dValue As Double
Public Shared Widening Operator CType(ByVal d As RDouble) As Double
Return d._dValue
End Operator
Public Shared Narrowing Operator CType(ByVal d As Double) As RDouble
Return New RDouble(d)
End Operator
End Class
Sub Main()
Dim rd As New RDouble(50.0, 10.0, 100.0)
rd = 20.54
Dim D As Double
D = Math.Round(rd)
End Sub
The problem with this code is of course that any assignment to the RDouble causes its boundaries to be "reset" since a new one is created with the default _MinValue and _MaxValue; and with the conversion operators being shared there is no way to access the Min/Max values of an instance.
Is there any way to fix this?
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If I understand what you're doing correctly, there is no way to fix this. You're trying to use a class instance as a value type and that doesn't work.
Take a look at the BigInterger structure in .NET 4.0 and 4.5. This is about the closest you're going to get.
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Let me explain in advanced what my goal is and then later I will ask the question. I have to get data from an Oracle database that is spread over several tables. The database connection and view to get the data is already up and running. I am now breaking my head over what the best way is to use the data from the database. The system I am working on work per document. To each document there needs to be data added from the database. I can run a query for each document when needed but I am thinking of loading all the data in to a recordset and use that recordset as a database. I know that if the amount of data is large the memory of the clients computer needs to be sufficient.
So the question now is how would I go about with this?
What is the best way of doing this?
Can I cache the record sets data and then perform SELECT * FROM obj.Recordset?
Any information will help here.
Thanks in advanced.
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You'd have to "roll your own" class to do this. VBScript doesn't have any built-in caching capabilities.
In my humble opinion, I would move this project up to PowerShell at the very least, which has native access to anynthing in the .NET Framework, including it's built-in caching classes.
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Thanks for the reply. But I can't move to Powershell because this scripting has to be done within an application that only can use VBScript. Actually the script language is called WinWrap Basic.
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oh....joy.
OK, then you would need to roll your own class to do the caching. Your biggest problem is going to be implementing a some kind of SQL (or some other dialect you invent) parser to do queries against the cached data.
OOOOORRRRR you could write a COM-exposed class in C# or VB.NET and use the DataTable.Select to do the heavy lifting for you. Then you would need to install and register this component and have to VBScript code CreateObject an instance of it, ...blah, blah, blah.
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I wanted to avoid installing extra libraries and keep the footprint on the client minimal. I already used a DSN-less connection to the database.
I can instantiate a recordset object so why can't I use the properties you mentioned of the recordset object?
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Feurich wrote: I already used a DSN-less connection to the database.
Which is very common. All a DSN is is a connection string in a text file. Ask some people why their obsessed with using a DSN and they can't give you an answer other than "that's the way I was taught!"
Feurich wrote: I can instantiate a recordset object so why can't I use the properties you
mentioned of the recordset object?
You can, so long as you don't want to do "SELECT * FROM ..." on that RecrodSet object. You can Filter on the RecordSet and alter what it iteractes over, but whether that will do what you want is unknown. Only you can answer that question.
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Feurich wrote: can instantiate a recordset object so why can't I use the properties you
mentioned of the recordset object?
...and because the Select method doesn't exist on the ODBC.RecordSet object. It exists on .NET's DataTable class, which VBScript cannot use unless you write a COM-exposed wrapper class around it as I mentioned.
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Thanks for your reply and time. I'll keep your suggestions in mind and try to keep to my goals while considering your comments.
Best regards,
Eric
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i am doing my project in visualbasic 6.0.In this i need to store and display the id(data) in VB 6.0,which is coming from the arduino usb cable.
tips are welcome...
thanks
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I suggest you promptly abandon VB6 for any development, since it's been a dead for years now, and replace it with VB.NET. You can get a free version here[^].
Then you can research serial communication to talk to the Arduino. Google for something like "VB.NET serial communication".
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Mainstream Support for Microsoft Visual Basic 6.0 ended on March 31, 2005. (I'm gonna put that in the signature, can't be repeated often enough it seems)
That's also the year the Arduino was born.
Bastard Programmer from Hell 
If you can't read my code, try converting it here[^]
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Hi brow !!!
What is the code for calling onscreenkyeboard (OSK) in vb.6 please help me.
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Launching an external app is described here[^].
VB6 is deprecated. It's no longer sold, nor supported. I will not be answering much questions on it either.
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
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I am trying to launch Silverlight 5 Out of Browser application without using a bat file. I would like the code contained in one vbscript. This is the code im working with.
Dim objShell,stArgs
strFile = "File Location"
strFileSrc = "URL file"
Set objShell = WScript.CreateObject( "WScript.Shell" )
objShell.Exec("""%ProgramFiles%\Microsoft Silverlight\sllauncher.exe""")
objShell.strArgs("/emulate:""" & strFile & """, /origin:""" & strFileSrc & """, /overwrite")
Set objShell = Nothing
I get the SlLauncher code box but I get
Line 7 Char 1
Error : Object doesn't support this property or method
Code: 800A01B6
Source: Microsoft VBscript runtime error
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ChrisDuti wrote: Error : Object doesn't support this property or method
The method "strArgs" does not exist in the WScript.Shell object. I suggest you concatenate the arguments to the file you want to run, and use the "run" method. Or Google for a different example 
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
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You are correct I forgot to put in strArgs = Agruments
updating now
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Cleaning up the code I put this:
Dim objShell
strFile = "File_Location.xap"
strFileSrc = "Source_Url"
strArgs = "/emulate:""" & strFile & """, /origin:""" & strFileSrc & """, /overwrite"
Set objShell = WScript.CreateObject( "WScript.Shell" )
objShell.Exec("""%ProgramFiles%\Microsoft Silverlight\sllauncher.exe"" " & strArgs)
On launch ... nothing.
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..does it launch if you omit the arguments? If yes, then we should focus on those.
objShell.Exec("""%ProgramFiles%\Microsoft Silverlight\sllauncher.exe"" " & strArgs)
I'd change that to
executeThis = """%ProgramFiles%\Microsoft Silverlight\sllauncher.exe"" " & strArgs
objShell.Exec(executeThis) Thus gives you the opportunity to inspect what's being passed, even if it is using a MsgBox.
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
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How can I create tables,store procedure, and trigger using vb 2008 installer class during apps installation
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Don't forget your any indexes you may have built.
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This is normally done by running create scripts during the installation.
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Please I want restore a database using vb 2008 installer class during Application Deployment.
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