Hello,
I am brand new to visual basic, so please excuse me if this is an easy question. I have a form with several checkboxes. I want to make it so that if any checkbox is checked, its label goes from gray to black. I have figured out how to do it for one checkbox, but I can't figure out how to handle many at the same time. Here is what I have so far:
Private Sub sidingStyle1Include_cb_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles sidingStyle1Include_cb.CheckedChanged
If (Style1Include_cb.Checked = True) Then
Style1Include_cb.ForeColor = Color.Black
' If CheckBox is unchecked then set text to grey. ElseIf ( Style1Include_cb.Checked = False) ThenStyle1Include_cb.ForeColor = Color.Gray
End IfThank you for any guidance
How to write a sub for several checkboxes at once
shamrock17
... Handles sidingStyle1Include_cb.CheckedChanged, OtherCheckBox.CheckedChanged, ...
If not, you will need to add event handlers as part of the code where you make the checkbox. The code for that would look something like this:
Dim cb As New CheckBox
AddHandler cb.CheckedChanged, AddressOf sidingStyle1Include_cb_CheckedChanged
Me.Controls.Add(cb)
Mark53
On first look, I thought that would be a nice idea. But taking a look again at what the OP is trying to achieve, it may or may not be what the OP's looking for. Even with a second handler for each individual checkbox, you would still need to know what textboxes need to have their color changed. The second event handler doesn't really buy you a whole lot except that it would avoid the if-else (or select case) statement in the single event handler. The OP would still have to "know" what textboxes need to have their color changed for a particular checkbox. By setting the Tag, you'd have a more generic way of handling this since you would not have to do txtBox.ForeColor = Color.Black for all the textboxes that need the color changed. Of course, if there's only say 1 or 2 textboxes, both yours and mine would simply be an added overhead.
Imran.
Mltronik
You are right, Imran.
The reason I thoughtof it that way is that you only have to look at code to see which checkbox is doing what, and not transition back to the designer to see what each text box tag setting is. Personal preference for me, I suppose. However, having said that, you could set the tags programmatically, too
.
Ramakrishnan Thangavel
That worked great. Thank you again.
Azman
Imran, Thank you again for helping on this issue. I think your idea is pretty good if there is really no way to dynamically evaluate variables in VB (is that correct ). I still have a problem though.
I wanted to take your idea of using tags a step further by just looping through all the controls and setting the color of any control that has a matching tag name. The problem I am running into though is that my form has a group of tabs on it and inside the tabs are 8 group boxes. From what I can tell using the code above, only the controls that aren't inside the tab group are looped through. So I added the name of the tab group into the designator for the controls, but then I found that it doesn't look inside the groups--it only loops through the names of the group boxes...and that's where I am stuck. I have given the group boxes the same tags as the controls inside the group boxes, but I still don't know how to tell VB to look at the controls inside of those group boxes OR to look at every control on the entire form:
If
chkBox.Checked ThenchkBox.ForeColor = Color.Black
For Each ctrl As Control In Me.projectType_tab.SelectedTab.Controls
If ctrl.Tag = chkBox.Tag Then
ctrl.ForeColor = Color.Black
End If NextThank you again
Dennis van.der Stelt
There are couple of ways to do this. Note that you can have just one handler for multiple events as long as the events have the same method signatures. So, in your case, since you need to write the same handler for all your checkboxes, here's one way you could do it:
Private Sub CheckBox_CheckedChanged(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles CheckBox1.CheckedChanged, _
CheckBox2.CheckedChanged, CheckBox3.CheckedChanged
Dim chkBox As CheckBox = DirectCast(sender, CheckBox)
If chkBox.Checked Then
chkBox.ForeColor = Color.Black
Else
chkBox.ForeColor = Color.Gray
End If
End Sub
Note the way you can add the events you want handled after the "Handles" keyword by your handler CheckBox_CheckedChanged. Another way to do it is using the AddHanlder keyword. You can attach your handler to the CheckedChanged event of all your checkboxes in the Form_Load. The functionality remains the same. Here's the code for that:
Private Sub Form1_Load(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles MyBase.Load
AddHandler CheckBox1.CheckedChanged, AddressOf CheckBox1_CheckedChanged
AddHandler CheckBox2.CheckedChanged, AddressOf CheckBox1_CheckedChanged
AddHandler CheckBox3.CheckedChanged, AddressOf CheckBox1_CheckedChanged
End Sub
Private Sub CheckBox1_CheckedChanged(ByVal sender As System.Object, _
ByVal e As System.EventArgs)
Dim chkBox As CheckBox = DirectCast(sender, CheckBox)
If chkBox.Checked Then
chkBox.ForeColor = Color.Black
Else
chkBox.ForeColor = Color.Gray
End If
End SubIf you have a lot of checkboxes and you're sure you need to add the same handler for all of them, you could something like this:
For Each ctrl As Control In Me.Controls
If TypeOf ctrl Is CheckBox Then
AddHandler DirectCast(ctrl, CheckBox).CheckedChanged, _
AddressOf CheckBox1_CheckedChanged
End If
Next
If you have a panel (or some other container control) on which those checkboxes are placed, make sure to recursively look through its child controls as well (that is, only if you need to attach the handler).
hope that helps,
Imran.
Les26739
Sorry to interrupt, but instead of using the tag property (which is a real nice idea), you can add multiple handlers for events.
Something like:
Both event handlers would fire when checkbox1 value changes. Then you can have a routine to set the text values as appropriately (You can even have many event handlers per control - don't know if there's a limit, but it'd be interesting to find out!)
vitalcc
You don't need to give the groupbox tag names (atleast not for this purpose). A groupbox is a container control just like a form (and panel control, etc). So, the controls in within your groupbox will be part of the groupbox's Controls collection. Here's how you would do it:
If chkBox.Checked Then
Hope that helps,chkBox.ForeColor = Color.Black
For Each ctrl As Control In Me.projectType_tab.SelectedTab.Controls
If TypeOf ctrl Is GroupBox Then
For Each ctrl2 As Control In ctrl.Controls
If ctrl2.Tag = chkBox.Tag Then
ctrl2.ForeColor = Color.Black
End If
Next ctrl2
End If
'If there are textboxes outside of a groupbox
If ctrl.Tag = chkBox.Tag Then
ctrl.ForeColor = Color.Black
End If
Next ctrl
End If
Imran.
RogerH
One way to accomplish this would be to use the Tag property of the TextBoxes. So, say you have 3 textboxes which need to change color basesd on the whether or not CheckBox1 is checked. Set it's Tag property to "CheckBox1" and then in your code - rather in your CheckedChanged handler, you can do this:
If Object.ReferenceEquals(chkBox, CheckBox1) Then
That's not a whole lot better but certainly better than doing it all in code.For Each ctrl As Control In Me.Controls
If TypeOf ctrl Is TextBox AndAlso _
CStr(ctrl.Tag) = "CheckBox1" Then
'change color of this textbox
End If
Next
End If
hope that helps,
Imran.
rcodyr
I have a question about this routine:
Private Sub CheckBox_CheckedChanged(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles CheckBox1.CheckedChanged, _
CheckBox2.CheckedChanged, CheckBox3.CheckedChanged
Dim chkBox As CheckBox = DirectCast(sender, CheckBox)
If chkBox.Checked Then
chkBox.ForeColor = Color.Black
Else
chkBox.ForeColor = Color.Gray
End If
End Sub
Is there a way to get the name of which of the checkboxes is being handled I'd like to change the color of some textbox fields that go along with each checkbox, so I figure if I know which checkbox is being handled by name, I can determine which other fields to work with based on that name. The thing is, I know I can just reference "chkBox.Name" to get the name of that box, but then how would I go about dynamically creating the names of the related textboxes.
So when
car_Enabled_cb is turned on, I would also want to change car_Name_tb,car_Brand_tb and car_Engine_tb
Do I have to just bite the bullet and use an IF statement to check which one is turned on and then deal with the text boxes or can I somehow do this dynamically
Thanks