Visual Basic

9-Feb-05 4:45

Is there any one how can give me an idea how to convert a string containing "ToDay()" to the expresion ToDay(). For example:

Dim str as string = "ToDay()"
dim newstr as string = ???str??? 'newstr=9/2/2005

Thanks

numbrel9-Feb-05 8:46

9-Feb-05 8:46

Maybe if you can give a brief explanation of what you are trying to accomplish with this, an answer may be found.

Your example just creates two strings but there's no explanation of what they are for.

zaxos9-Feb-05 20:49

9-Feb-05 20:49

Dear numbrel,
Thank you for your reply. Here is a more detail explanation. The first string contain an expresion, for examble TODAY() or NOW() etc. I am looking a way to use the contents of this string as a vb.net command and give the result to the second string.
I hope this is more clear to you.
Regards zaxos

numbrel10-Feb-05 4:53

10-Feb-05 4:53

zaxos,

It's still not total clear. Maybe if we start at the end.

You want a string containing the result from a function called using the first string.

You can't hard code the function call because....?? Maybe you want to use different functions and you want to use a variable for the function name (the first string is a variable?)

zaxos10-Feb-05 7:22

10-Feb-05 7:22

Yes I want a string containing the result from a function called using the first string. More precicely I dont want the contents of the string
"TODAY()" but the result of the function TODAY().

Regards zaxos

numbrel10-Feb-05 7:49

10-Feb-05 7:49

I still don't understand why you want to use the first string.

Why can't you use:
sResult = Today(), where Today() returns a string and sResult is the variable to hold the second string?

Why do you need to use the first string?

zaxos11-Feb-05 3:40

11-Feb-05 3:40

thank for replying again to my message.
i can't use today() as you suggest because i don't know it.i have for example a textbox in which the user can type anything he wants.So i can't do what you are saying i need to keep in a variable the thing that the user typed and then evaluate that string.i have dim str as string = textbox.text
and i want to use that variable str in order to evaluate that string.
in foxpro i could use what is called macro substitution.so in foxpro i would do something like that dim str1 as string = &str.
i want to do exactly what the debugger does in vb.net when you drop the variable in the watch window it show you the value of the variable.

thanks

numbrel11-Feb-05 8:23

11-Feb-05 8:23

i need to keep in a variable the thing that the user typed and then evaluate that string.i have dim str as string = textbox.text
and i want to use that variable str in order to evaluate that string.

My understanding is that you want to use the input from the user to call a function which would return a string.

If that is correct, my suggestion is to use Select Case.

dim str as string = textbox.text<br />
dim str2 as string<br />
<br />
Select Case str<br />
   Case "function1"<br />
      str2 = function1()<br />
   Case "function2"<br />
      str2 = function2()<br />
   Case "function3"<br />
      str2 = function3()<br />
   .<br />
   .<br />
   .<br />
End Select

Am I close to understanding what you want?

zaxos13-Feb-05 20:05

13-Feb-05 20:05

yes this is what i want to do.
i thought that must be a way not to use something like select case since we don't know the input of the user.i suppose that there is no way in vb.net to do something like the one i described you that we can do in foxpro.

Christian Graus9-Feb-05 10:04

Christian Graus

9-Feb-05 10:04

SQL does this, and I believe VBScript can do it, too. Hopefully, VB.NET doesn't, but it would not surprise me. Is there a command like EXEC, or EXECUTE, perhaps ?

Why would you want to do such a thing ? Basically, you want to take a string, and pass it to the compiler. VB.NET should be able to do this, seeing as .NET compiles on the fly anyhow.

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

zaxos11-Feb-05 3:45

11-Feb-05 3:45

Thanks for replying to my question.
Can you give me more information about the thing you suggested passing a string to the compiler vb.net in order to evaluate it.Any example or suggestion would be great.

Thanks in advance

Serialize help

MrBean9-Feb-05 3:27

MrBean

9-Feb-05 3:27

I'm looking into serializing some of my classess to/from XML and need some help.

Imagine the scenario below (these are not my actual classes, but illustrate the problem)...

<br />
<br />
Public Class MyReport<br />
  <br />
  Public m_Title as String<br />
  Public m_BackColor as Color<br />
  Public m_Objects as new ArrayList ' Contains MyReportObject objects<br />
<br />
End Class<br />
<br />
Public Class MyReportObject<br />
  <br />
  Public m_Text as String<br />
  Public m_X as Integer<br />
  Public m_Y as Integer<br />
<br />
End Class<br />

How do I enable my two classes for serializing ?

I have tried adding different XML attributes to the class members and the Serializable attribute to the classes :

<br />
<br />
<Serializable()> Public Class MyReport<br />
  <br />
  <Xml.Serialization.XmlAttribute()> Public m_Title as String<br />
  <Xml.Serialization.XmlAttribute()> Public m_BackColor as Color<br />
  <Xml.Serialization.XmlElement()> Public m_Objects as new ArrayList ' Contains several MyReportObject objects<br />
<br />
End Class<br />
<br />
<Serializable()> Public Class MyReportObject<br />
  <br />
  <Xml.Serialization.XmlElement()> Public m_Text as String<br />
  <Xml.Serialization.XmlElement()> Public m_X as Integer<br />
  <Xml.Serialization.XmlElement()> Public m_Y as Integer<br />
<br />
End Class<br />

But I still get an error when I try to serialize the MyReport class ?

What am I doing wrong ?

Dave Kreskowiak9-Feb-05 16:51

Dave Kreskowiak

9-Feb-05 16:51

Your class isn't attributed Serializable and/or does not implement the ISerializable interface. You can't just tag your classes properties with the attributes you have and expect it to work.

See the ISerializable Interface[^] docs for more information.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Anonymous9-Feb-05 21:38

Anonymous

9-Feb-05 21:38

Sorry... actually, my classes are marked as serializable :

<br />
<Serializable()> Public Class MyReport<br />
<br />
<xml.Serialization.XmlAttribute()> Public m_Title as String<br />
<xml.Serialization.XmlAttribute()> Public m_BackColor as Color<br />
<xml.Serialization.XmlElement()> Public m_Objects as new ArrayList ' Contains several MyReportObject objects<br />
<br />
End Class<br />
<br />
<Serializable()> Public Class MyReportObject<br />
<br />
<xml.Serialization.XmlElement()> Public m_Text as String<br />
<xml.Serialization.XmlElement()> Public m_X as Integer<br />
<xml.Serialization.XmlElement()> Public m_Y as Integer<br />
<br />
End Class<br />

But somehow my code fails if the m_Objects arraylist contains objects MyReportObject - why ?

I have tried a number of different combinations so the code above isn't 100% accurate, but should give a good idea of what I'm trying to do.

Please help !!

MrBean9-Feb-05 21:41

MrBean

9-Feb-05 21:41

Sorry for the above post... the forum somehow didn't recognize my account ?!?!?! (grrr!)

Anyway... the two classes ARE marked as < Serializable() > but not shown in the code above (again a forum bug ?)

Here the code AGAIN with the Serializable tags Smile | :)

...

<br />
<br />
< Serializable() > Public Class MyReport<br />
<br />
<xml.Serialization.XmlAttribute()> Public m_Title as String<br />
<xml.Serialization.XmlAttribute()> Public m_BackColor as Color<br />
<xml.Serialization.XmlElement()> Public m_Objects as new ArrayList ' Contains several MyReportObject objects<br />
<br />
End Class<br />
<br />
< Serializable() > Public Class MyReportObject<br />
<br />
<xml.Serialization.XmlElement()> Public m_Text as String<br />
<xml.Serialization.XmlElement()> Public m_X as Integer<br />
<xml.Serialization.XmlElement()> Public m_Y as Integer<br />
<br />
End Class<br />
<br />

Dave Kreskowiak10-Feb-05 5:45

Dave Kreskowiak

10-Feb-05 5:45

Ok, so it is. It didn't come up before because the < and > brackets weren't typed in correctly. Not beacuse of a bug in CP's code.

Now, what about your serialization code?

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

MrBean10-Feb-05 20:54

MrBean

10-Feb-05 20:54

Here's the current and complete test source including the test function :

<code>

Imports System.Xml.Serialization

<Serializable()> Public Class MyReport

Public m_Title As String
Public m_BackColor As Color
Public m_Objects As New ArrayList ' Contains several MyReportObject objects

End Class

<Serializable()> Public Class MyReportObject

Public m_Text As String
Public m_X As Integer
Public m_Y As Integer

End Class

Module TestFunctions

Public Sub Test()

' Making test data...

Dim oRep As New MyReport
oRep.m_Title = "Some new report..."
oRep.m_BackColor = oRep.m_BackColor.WhiteSmoke

Dim oObj As New MyReportObject
oObj.m_Text = "A text..."
oObj.m_X = 10
oObj.m_Y = 10

oRep.m_Objects.Add(oObj) ' Leave this line out, and serializeing below will succeed !

Try

' Serialize to XML file...
Dim file As New System.io.FileStream("c:\MyReport.xml", IO.FileMode.Create)
Dim ser As New System.Xml.Serialization.XmlSerializer(oRep.GetType)
ser.Serialize(file, oRep)
ser = Nothing
file.Close()
file = Nothing

MsgBox("Done!")

Catch ex As Exception
MsgBox(ex.Message & vbCr & vbCr & ex.InnerException.Message)
End Try

End Sub

End Module

</code>