Referring to controls using String Variables??

  • Thread starter Thread starter Paul Bromley
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Paul Bromley

Can someone tell me if there is any way of doing this? As an example - let
us say that I have a button called cmdLetter and a textbox called txtLetter,
can I in some way manipulate the names of these controsl to extract the
string Letter and then use this string later to refer to the Controls?? I
can think of a number of ways in my coding that this would be very useful -
especially in a number of applications where I have a number of related
textboxes and command buttons. I was hoping setting the Text property of the
relevant command button so that I could then pass this as a parameter to a
Class and identify the relevant button and textbox with far less coding.

Hope that you understand what I am getting at.


Best wishes


Paul Bromley
 
* "Paul Bromley said:
Can someone tell me if there is any way of doing this? As an example - let
us say that I have a button called cmdLetter and a textbox called txtLetter,
Click to expand...

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(ControlName, ctr)
If Not ctr Is Nothing Then
Return ctr
End If
End If
Next ctr
End Function
///

Usage:

\\\
DirectCast(FindControl("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 DynamicPictureBox As New PictureBox()
DynamicPictureBox.Name = "PictureBox1"
m_Controls.Add(DynamicPictureBox.Name, DynamicPictureBox)
///

Looking for a control:

\\\
Dim p As PictureBox = DirectCast(m_Controls.Item("PictureBox1"), PictureBox)
///

Removing a control:

\\\
m_Controls.Remove("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/e...ngControlArraysInVisualBasicNETVisualCNET.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.
 
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