Trying to execute something stored in variable

[Mike TI]

April 22, 2006

Hi all

I want to execute a command stored in a variable, eg I may store:

Form1.Show()
or
Form2.Show()

in the variable and then execute whatever is in the variable.

I read about the System.CodeDom namespace in MSDN, however I am unable to
get the example given to work. Does this do what I have in mind ?

*****
Dim start As New CodeEntryPointMethod()
Dim cs1 As New CodeMethodInvokeExpression( _
New CodeTypeReferenceExpression("System.Console"), _
"WriteLine", _
New CodePrimitiveExpression("Hello World!") )
start.Statements.Add(cs1)
*****

Please assist

[Cor Ligthert [MVP]]

Mike,

Are you person 1001 who tries to make a kind of Office Access Solution, you
change to succeed is probably the same as if you try to make a new
professional Texteditor?

It leads probably to nothing, however have a search in this newsgroup for
all those late binding solutinons using reflection.

Just my idea, maybe it does not help, or in the other hand maybe a lot
saving you a lot of time.

Cor
"Mike TI" <su*******@hotmail.com> schreef in bericht
news:%2****************@TK2MSFTNGP05.phx.gbl...

April 22, 2006

Hi all

I want to execute a command stored in a variable, eg I may store:

Form1.Show()
or
Form2.Show()

in the variable and then execute whatever is in the variable.

I read about the System.CodeDom namespace in MSDN, however I am unable to
get the example given to work. Does this do what I have in mind ?

*****
Dim start As New CodeEntryPointMethod()
Dim cs1 As New CodeMethodInvokeExpression( _
New CodeTypeReferenceExpression("System.Console"), _
"WriteLine", _
New CodePrimitiveExpression("Hello World!") )
start.Statements.Add(cs1)
*****

Please assist

[Steve_Black]

Hi Mike,

I have two routines that allow you to either open a form if the name of
the form is stored in a variable, or call a function (or subroutine) if
the name of the function is stored in a variable:

Note - The functions that are being called are actually methods of a
class, and the routine to call these functions is stored in the same
class. So, this code will need to be modified if you can't arrange
your application so that all possible functions that get called in this
manor are located in the same class. Most of the time names of
functions aren't stored in variables. I happen to build a Menu Strip
on the fly based on information in a database. 99% of the time when a
menu item is clicked, I open a form (using the below code). However,
there are a couple of situations when I need to call a function when a
menu item is clicked.

Here's the class for calling a function stored in a variable:

Imports System.Reflection
Public Class CallFunctions
Public Function ExecuteMethods(ByVal prmMethodName As String,
Optional ByVal prmParams() As Object = Nothing) As Object
'Create a type object and store the type of the object passed
Dim objType As Type = Me.GetType

'Declare a MethodInfo object to store the Methods of the class
Dim objMethodInfo As MethodInfo

'Get the MethodInfo for the current class. Binding Flags are
specified to get the public and private Methods of this class. When
'Public or Non-Public is specified in the BindingFlags, it is
also necessary to specify Static or Instance
objMethodInfo = objType.GetMethod(prmMethodName,
BindingFlags.NonPublic Or BindingFlags.Public Or BindingFlags.Static Or
BindingFlags.Instance)

Return objMethodInfo.Invoke(Me, prmParams)
End Function

Public Sub SubRoutine1()
.......Your code here
End Sub

Public Sub SubRoutine2()
......Your code here
End Sub

Public Function(prmArgument1 as String) As String
.....Your code here
End Sub
End Class

You would use this class in your code as follows:

Dim cf As New CallFunctions
Call cf.ExecuteMethods(variablename, array of parameters)
You can leave the second argument empty if you aren't passing any
parameters.
On the other hand, if you need to open a form and the name of the form
is stored in a variable, you can do this:

Public Sub OpenForm(prmFormName As String)
Dim app As System.Reflection.Assembly =
System.Reflection.Assembly.GetExecutingAssembly()
Try
Dim frm As Form = app.CreateInstance("Namespace." &
prmFormName, True)
frm.Show()
Catch e as Exception
End try
End Sub

You need to substitute "Namespace." with your namespace (and the
period).

Please note that I cannot take full credit for these routines. I have
found most of this in other places on the Internet and I modified them
slightly for my use.

Hope this helps.

Steve

[Mike TI]

April 23, 2006

You have made my day.

Thank you.
Mike TI

<St*********@EagleCCI.com> wrote in message
news:11**********************@j33g2000cwa.googlegr oups.com...

Hi Mike,

I have two routines that allow you to either open a form if the name of
the form is stored in a variable, or call a function (or subroutine) if
the name of the function is stored in a variable:

Note - The functions that are being called are actually methods of a
class, and the routine to call these functions is stored in the same
class. So, this code will need to be modified if you can't arrange
your application so that all possible functions that get called in this
manor are located in the same class. Most of the time names of
functions aren't stored in variables. I happen to build a Menu Strip
on the fly based on information in a database. 99% of the time when a
menu item is clicked, I open a form (using the below code). However,
there are a couple of situations when I need to call a function when a
menu item is clicked.

Here's the class for calling a function stored in a variable:

Imports System.Reflection
Public Class CallFunctions
Public Function ExecuteMethods(ByVal prmMethodName As String,
Optional ByVal prmParams() As Object = Nothing) As Object
'Create a type object and store the type of the object passed
Dim objType As Type = Me.GetType

'Declare a MethodInfo object to store the Methods of the class
Dim objMethodInfo As MethodInfo

'Get the MethodInfo for the current class. Binding Flags are
specified to get the public and private Methods of this class. When
'Public or Non-Public is specified in the BindingFlags, it is
also necessary to specify Static or Instance
objMethodInfo = objType.GetMethod(prmMethodName,
BindingFlags.NonPublic Or BindingFlags.Public Or BindingFlags.Static Or
BindingFlags.Instance)

Return objMethodInfo.Invoke(Me, prmParams)
End Function

Public Sub SubRoutine1()
.......Your code here
End Sub

Public Sub SubRoutine2()
......Your code here
End Sub

Public Function(prmArgument1 as String) As String
.....Your code here
End Sub
End Class

You would use this class in your code as follows:

Dim cf As New CallFunctions
Call cf.ExecuteMethods(variablename, array of parameters)
You can leave the second argument empty if you aren't passing any
parameters.
On the other hand, if you need to open a form and the name of the form
is stored in a variable, you can do this:

Public Sub OpenForm(prmFormName As String)
Dim app As System.Reflection.Assembly =
System.Reflection.Assembly.GetExecutingAssembly()
Try
Dim frm As Form = app.CreateInstance("Namespace." &
prmFormName, True)
frm.Show()
Catch e as Exception
End try
End Sub

You need to substitute "Namespace." with your namespace (and the
period).

Please note that I cannot take full credit for these routines. I have
found most of this in other places on the Internet and I modified them
slightly for my use.

Hope this helps.

Steve

[Steve_Black]

You're welcome. Glad I could help.

Steve