Calling Sub Procedure with a variable

[ILCSP]

Hi, I'm using VB.Net (2003) and I have a question. Does anyone knows
how to call a procedure using a variable? The variable will be equal to
the name of the procedure.

for example, if I have the following variable:

Public PrintTheSub as string

and the following subs:
Private Sub PrintOrdersReports ()
' the code for this sub goes here
End Sub

Private Sub PrintCustomerReports()
' the code for this sub goes here
End Sub

Private Sub PrintMonthlyReport()
' the code for this sub goes here
End Sub
and I have a button with the public variable in it:

Private Sub btnPrint_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnPrint.Click
' here will go the variable that will call one of the 3 subs.
PrintTheSub
End Sub

And during the process but before getting to the print button, the
PrintTheSub variable = "PrintCustomerReports"

How can I make the print button to accept the variable value and when
clicked it could call the PrintCustomerReports sub?
Any help would be appreciated.

[Al Reid]

<IL***@NETZERO.NETwrote in message
news:11*********************@75g2000cwc.googlegrou ps.com...

Hi, I'm using VB.Net (2003) and I have a question. Does anyone knows
how to call a procedure using a variable? The variable will be equal to
the name of the procedure.

for example, if I have the following variable:

Public PrintTheSub as string

and the following subs:
Private Sub PrintOrdersReports ()
' the code for this sub goes here
End Sub

Private Sub PrintCustomerReports()
' the code for this sub goes here
End Sub

Private Sub PrintMonthlyReport()
' the code for this sub goes here
End Sub
and I have a button with the public variable in it:

Private Sub btnPrint_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnPrint.Click
' here will go the variable that will call one of the 3 subs.
PrintTheSub
End Sub

And during the process but before getting to the print button, the
PrintTheSub variable = "PrintCustomerReports"

How can I make the print button to accept the variable value and when
clicked it could call the PrintCustomerReports sub?
Any help would be appreciated.

How about an If...Then or a Select Case?

Private Sub btnPrint_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles
btnPrint.Click
Select Case PrintTheSub
Case "PrintCustomerReports"
PrintCustomerReports()

Case "PrintOrdersReports"
PrintOrdersReports()

Case "PrintMonthlyReport"
PrintMonthlyReport()
End Select

End Sub
I would probably make an Enum for the reports and use that instead of a
string.

--
Al Reid

[Mattias Sjögren]

You can use the CallByName function for this. But personally, I'd use
a delegate to refer to the method to be called instead of the
procedure name in a string.
Mattias

--
Mattias Sjögren [C# MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.

[ILCSP]

Hi Al, thanks for replying. I did think about a case statement, but
since the final project will have over 200 reports, the case statement
will not be as good as if I used the variable name.

I was hoping that application.run(PrintTheSub) was gonna work, but it
did not.
Al Reid wrote:

<IL***@NETZERO.NETwrote in message
news:11*********************@75g2000cwc.googlegrou ps.com...

Hi, I'm using VB.Net (2003) and I have a question. Does anyone knows
how to call a procedure using a variable? The variable will be equal to
the name of the procedure.

for example, if I have the following variable:

Public PrintTheSub as string

and the following subs:
Private Sub PrintOrdersReports ()
' the code for this sub goes here
End Sub

Private Sub PrintCustomerReports()
' the code for this sub goes here
End Sub

Private Sub PrintMonthlyReport()
' the code for this sub goes here
End Sub
and I have a button with the public variable in it:

Private Sub btnPrint_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnPrint.Click
' here will go the variable that will call one of the 3 subs.
PrintTheSub
End Sub

And during the process but before getting to the print button, the
PrintTheSub variable = "PrintCustomerReports"

How can I make the print button to accept the variable value and when
clicked it could call the PrintCustomerReports sub?
Any help would be appreciated.

How about an If...Then or a Select Case?

Private Sub btnPrint_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles
btnPrint.Click
Select Case PrintTheSub
Case "PrintCustomerReports"
PrintCustomerReports()

Case "PrintOrdersReports"
PrintOrdersReports()

Case "PrintMonthlyReport"
PrintMonthlyReport()
End Select

End Sub
I would probably make an Enum for the reports and use that instead of a
string.

--
Al Reid

[tomb]

You could do this:
In the declarations:

Delegate Sub PrintOReport()
Delegate Sub PrintCReport()
Delegate Sub PrintMReport()
Private OP as PrintOReport
Private CP as PrintCReport
Private MP as PrintMReport
Private sPrint As [Delegate]

In some proc, pass the three addresses of the real subs, like this:
public sub setDelegates(byref so as PrintOReport, byref sc as
PrintCReport, byref sm as PrintMReport)
op=so
cp=sc
mp=sm
end sub

Then in your code logic, set sPrint equal to one of the delegate
variables. When the button is clicked, the correct proc will be called.

T
IL***@NETZERO.NET wrote:

>Hi, I'm using VB.Net (2003) and I have a question. Does anyone knows
how to call a procedure using a variable? The variable will be equal to
the name of the procedure.

for example, if I have the following variable:

Public PrintTheSub as string

and the following subs:
Private Sub PrintOrdersReports ()
' the code for this sub goes here
End Sub

Private Sub PrintCustomerReports()
' the code for this sub goes here
End Sub

Private Sub PrintMonthlyReport()
' the code for this sub goes here
End Sub
and I have a button with the public variable in it:

Private Sub btnPrint_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnPrint.Click
' here will go the variable that will call one of the 3 subs.
PrintTheSub
End Sub

And during the process but before getting to the print button, the
PrintTheSub variable = "PrintCustomerReports"

How can I make the print button to accept the variable value and when
clicked it could call the PrintCustomerReports sub?
Any help would be appreciated.

[Branco Medeiros]

IL***@NETZERO.NET wrote:

Hi, I'm using VB.Net (2003) and I have a question. Does anyone knows
how to call a procedure using a variable? The variable will be equal to
the name of the procedure.

<snip>

Public PrintTheSub as string

<snip>

Private Sub PrintOrdersReports ()
' the code for this sub goes here
End Sub

Private Sub PrintCustomerReports()
' the code for this sub goes here
End Sub

Private Sub PrintMonthlyReport()
' the code for this sub goes here
End Sub

<snip>

Private Sub btnPrint_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnPrint.Click
' here will go the variable that will call one of the 3 subs.
PrintTheSub
End Sub

<snip>

How can I make the print button to accept the variable value and when
clicked it could call the PrintCustomerReports sub?

I guess that you're best bet, as suggested, is using a delegate instead
of the method name:

Delegate Sub PrintReportDelegate()
Dim PrintTheSub As PrintReportDelegate

Private Sub btnPrint_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnPrint.Click

If Not PrintTheSub Is Nothing Then PrintTheSub.Invoke()

End Sub

And then, instead of assigning a sub name to PrintTheSub, you'd have:

PrintTheSub = AddressOf PrintOrdersReports

or

PrintTheSub = AddressOf PrintCustomerReports

and so on.

HTH.

Regards,

Branco.

[Al Reid]

Agreed. Had you stated the number of reports, I would not have made that
suggestion. It seems that CallByName or reflection would be more
appropriate.

--
Al Reid

<IL***@NETZERO.NETwrote in message
news:11*********************@35g2000cwc.googlegrou ps.com...

Hi Al, thanks for replying. I did think about a case statement, but
since the final project will have over 200 reports, the case statement
will not be as good as if I used the variable name.

I was hoping that application.run(PrintTheSub) was gonna work, but it
did not.

[Herfried K. Wagner [MVP]]

<IL***@NETZERO.NETschrieb:

Hi, I'm using VB.Net (2003) and I have a question. Does anyone knows
how to call a procedure using a variable? The variable will be equal to
the name of the procedure.

Calling a method by its name
<URL:http://dotnet.mvps.org/dotnet/faqs/?id=callbyname&lang=en>

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://classicvb.org/petition/>