Reference Control help

[Merlin]

Hi

I have a control that allows embeddable editors, so for example I can set a
property of controlsEmbedda bleEditor =me.TextBox1 on my form, no problem
here - what I want to do is the same thing but from a string variable.

i.e. I have 14 controls that have a name which is a permutation of 4
characters, my program selects which control to use by a 4 character name
which matches a control name (it's a zillion times more complex than this
but for examples sake). my trouble is I know the name of the control to use,
and the control is contained on the form, but how do I reference it, as the
name is contained within a string i.e
controlsEmbedda bleEditor="myco ntrolname" can I ctype, Directcast e.t.c if so
how???

Many thanks.

Regards,

[Herfried K. Wagner [MVP]]

* "Merlin" <im*****@hotmai l.com> scripsit:

i.e. I have 14 controls that have a name which is a permutation of 4
characters, my program selects which control to use by a 4 character name
which matches a control name (it's a zillion times more complex than this
but for examples sake). my trouble is I know the name of the control to use,
and the control is contained on the form, but how do I reference it, as the
name is contained within a string i.e
controlsEmbedda bleEditor="myco ntrolname" can I ctype, Directcast e.t.c if so
how???

My FAQ:

\\\
Private Function FindControl( _
ByVal ControlName As String, _
ByVal CurrentControl As Control _
) As Control
Dim ctr As Control
For Each ctr In CurrentControl. Controls
If ctr.Name = ControlName Then
Return ctr
Else
ctr = FindControl(Con trolName, ctr)
If Not ctr Is Nothing Then
Return ctr
End If
End If
Next ctr
End Function
///

Usage:

\\\
DirectCast(Find Control("btnBla ", Me), Button).Enabled = False
///

Notice that the procedure listed above is "slow", if you have to access a
lot of controls by name very often, you should store references to them in a
'Hashtable' object. You can use the name of the control as key:

\\\
Private m_Controls As New Hashtable()
///

Adding a control:

\\\
Dim DynamicPictureB ox As New PictureBox()
DynamicPictureB ox.Name = "PictureBox 1"
m_Controls.Add( DynamicPictureB ox.Name, DynamicPictureB ox)
///

Looking for a control:

\\\
Dim p As PictureBox = DirectCast(m_Co ntrols.Item("Pi ctureBox1"), PictureBox)
///

Removing a control:

\\\
m_Controls.Remo ve("PictureBox1 ")
///

Sometimes it's even better to add the control to an array. This will allow
fast and easy index-based access to the control references:

\\\
Dim MyLabels() As Label = {Label1, Label2, ..., Label10}
///

Access by 'MyLabels(0)' to 'MyLabels(9)'.

Control arrays:

Control arrays, as known from VB6, are not included in VB.NET 2002/2003.

Creating Control Arrays in Visual Basic .NET and Visual C# .NET:
<URL:http://msdn.microsoft. com/library/en-us/dv_vstechart/html/vbtchCreatingCo ntrolArraysInVi sualBasicNETVis ualCNET.asp>

WinForms Controls--Creating Control Arrays in VB.NET
<URL:http://www.devx.com/vb2themax/Article/19907/>

In VS.NET "Whidbey" (2005) control arrays will be supported natively.

--
Herfried K. Wagner [MVP]
<URL:http://dotnet.mvps.org/>

[Merlin]

Many thanks Herfried.

Regards,
Merlin
"Herfried K. Wagner [MVP]" <hi************ ***@gmx.at> wrote in message
news:2g******** ****@uni-berlin.de...

* "Merlin" <im*****@hotmai l.com> scripsit:

i.e. I have 14 controls that have a name which is a permutation of 4
characters, my program selects which control to use by a 4 character name which matches a control name (it's a zillion times more complex than this but for examples sake). my trouble is I know the name of the control to use, and the control is contained on the form, but how do I reference it, as the name is contained within a string i.e
controlsEmbedda bleEditor="myco ntrolname" can I ctype, Directcast e.t.c if so how???
My FAQ:

\\\
Private Function FindControl( _
ByVal ControlName As String, _
ByVal CurrentControl As Control _
) As Control
Dim ctr As Control
For Each ctr In CurrentControl. Controls
If ctr.Name = ControlName Then
Return ctr
Else
ctr = FindControl(Con trolName, ctr)
If Not ctr Is Nothing Then
Return ctr
End If
End If
Next ctr
End Function
///

Usage:

\\\
DirectCast(Find Control("btnBla ", Me), Button).Enabled = False
///

Notice that the procedure listed above is "slow", if you have to access a
lot of controls by name very often, you should store references to them in

a 'Hashtable' object. You can use the name of the control as key:

\\\
Private m_Controls As New Hashtable()
///

Adding a control:

\\\
Dim DynamicPictureB ox As New PictureBox()
DynamicPictureB ox.Name = "PictureBox 1"
m_Controls.Add( DynamicPictureB ox.Name, DynamicPictureB ox)
///

Looking for a control:

\\\
Dim p As PictureBox = DirectCast(m_Co ntrols.Item("Pi ctureBox1"), PictureBox) ///

Removing a control:

\\\
m_Controls.Remo ve("PictureBox1 ")
///

Sometimes it's even better to add the control to an array. This will allow fast and easy index-based access to the control references:

\\\
Dim MyLabels() As Label = {Label1, Label2, ..., Label10}
///

Access by 'MyLabels(0)' to 'MyLabels(9)'.

Control arrays:

Control arrays, as known from VB6, are not included in VB.NET 2002/2003.

Creating Control Arrays in Visual Basic .NET and Visual C# .NET:
<URL:http://msdn.microsoft.com/library/en.../vbtchCreating
ControlArraysIn VisualBasicNETV isualCNET.asp>
WinForms Controls--Creating Control Arrays in VB.NET
<URL:http://www.devx.com/vb2themax/Article/19907/>

In VS.NET "Whidbey" (2005) control arrays will be supported natively.

--
Herfried K. Wagner [MVP]
<URL:http://dotnet.mvps.org/>