Do you wonder if your IT business is truly profitable or if you should raise your prices? Learn how to calculate your overhead burden using our free interactive tool and use it to determine the right price for your IT services. Start calculating Now!
VB.Net windows form application GotFocus event will not fire
I have a form with 20 controls on it. I want the on focus event to fire when one of the 'data' controls get the focus. (combo, Textbox, Checkbox)
Please have a look at the code and see if you can spot why the event is not firing when any of the controls get the focus.
Thank you.
Please have a look at the code and see if you can spot why the event is not firing when any of the controls get the focus.
Thank you.
Private Sub getDataValues(ByVal sender As Object, ByVal e As System.EventArgs) Handles DateBirth.GotFocus, Address1.GotFocus, Address2.GotFocus, _
Town.GotFocus, City.GotFocus, PostCode.GotFocus, cboMemberSection.GotFocus, cboMembershipType.GotFocus, _
cboMembershipType.GotFocus, chkActive.GotFocus, chkFeeEarner.GotFocus, CurrentGrade.GotFocus, Date_First_Joined.GotFocus, _
EC1_Mobile.GotFocus, EC1_Name.GotFocus, EC1_Number.GotFocus, EC1_Relationship.GotFocus, EC2_Mobile.GotFocus, _
EC2_Name.GotFocus, EC2_Number.GotFocus, EC2_Relationship.GotFocus, Email.GotFocus, FirstNM.GotFocus, Gender.GotFocus, _
LastNM.GotFocus, Mobile.GotFocus, PostCode.GotFocus, Telephone.GotFocus
'=================================================================================================================
'Description: Fires when any of the handled controls gets the focus
' The current value in the control is passed into the controls tag property for retrieval later on if
' the user clicks the 'undo' button on the form.
'Author:
'Date:
'Revised By:
'Last Revised:
'=================================================================================================================
'Dim ctl As System.Windows.Forms.Control
If UpdatingCombos = True Or LoadEvent = True Then 'stop this running if the form is loading up the sellected record
Exit Sub
Else
Dim ctlVal As String = ""
Dim ctlType As String = ""
Dim cbo As ComboBox
Dim txt As TextBox
Dim chk As CheckBox
Dim dte As DateTimePicker
Dim sType As String = sender.GetType.ToString
Dim sName As String = ""
Dim intLen As Integer = (Len(sender.GetType.ToString) - 21)
sType = sType.Substring(21, intLen)
Select Case sType
Case "TextBox"
txt = DirectCast(sender, TextBox)
sName = txt.Name
ctlVal = txt.Text
txt.Tag = ctlVal
Case "ComboBox"
cbo = DirectCast(sender, ComboBox)
sName = cbo.Name
ctlVal = cbo.SelectedText
Case "checkBox"
chk = DirectCast(sender, CheckBox)
sName = chk.Name
ctlVal = chk.Checked
Case "DateTimePicker"
dte = DirectCast(sender, DateTimePicker)
sName = dte.Name
ctlVal = dte.Value
End Select
LoadEvent = False
btnClear.Enabled = True
End If
End Sub
Do more with
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
Instead of that ugly hack with the GetType.Tostring, I would suggest a more direct If .. ElseIf structure to handle the detection of the type of control. It is possible that your control type string prefix is no longer exactly 21 characters if there was a change of project name or namespace.
If TypeOf (sender) Is TextBox Then
txt = DirectCast(sender, TextBox)
sName = txt.Name
ctlVal = txt.Text
txt.Tag = ctlVal
ElseIf TypeOf (sender) Is ComboBox Then
cbo = DirectCast(sender, ComboBox)
sName = cbo.Name
ctlVal = cbo.SelectedText
ElseIf TypeOf (sender) Is CheckBox Then
chk = DirectCast(sender, CheckBox)
sName = chk.Name
ctlVal = chk.Checked
ElseIf TypeOf (sender) Is DateTimePicker Then
dte = DirectCast(sender, DateTimePicker)
sName = dte.Name
ctlVal = dte.Value
End If
Well Mr Hews,
Your lofty and rather curt opinion of my code is duly noted........Perhaps you would now be good enough to use your expertise and have a go at answering my question - which was why my ugly hack code never fires. It does not raise errors - it just does not fire.
You may be a VB genuis, but you clearly lack any social skills. Re-read your comment and consider why your answer might just put a beginner off. I am just learning ,,,,do you get it, or are you such a genuis do you not remember that far back?
Your lofty and rather curt opinion of my code is duly noted........Perhaps you would now be good enough to use your expertise and have a go at answering my question - which was why my ugly hack code never fires. It does not raise errors - it just does not fire.
You may be a VB genuis, but you clearly lack any social skills. Re-read your comment and consider why your answer might just put a beginner off. I am just learning ,,,,do you get it, or are you such a genuis do you not remember that far back?
Didn't mean to get your hackles up. I've written my share of ugly hacks over the years, and really was not being judgmental, and sorry if I came across as harsh.
Since you never stated how you know that the event is not firing, I was offering instead that maybe it is firing, but the case statements are not being hit because the sType string is not picking up the right string. You can put a breakpoint on the first line that reads "If UpdatingCombos = True ... " to determine for sure that your code is not firing. (You should also confirm that that condition allows the subsequent code to run if the break point actually does get hit.)
Since you never stated how you know that the event is not firing, I was offering instead that maybe it is firing, but the case statements are not being hit because the sType string is not picking up the right string. You can put a breakpoint on the first line that reads "If UpdatingCombos = True ... " to determine for sure that your code is not firing. (You should also confirm that that condition allows the subsequent code to run if the break point actually does get hit.)
Apology happily accepted..It can get frustrating being a beginner.
Anyway, have run the code with a breakpoint in place and no joy. That was my first port of call, so I knew it was not the code causing an unexpected outcome.
I thought there may be a limit on the number of controls that can be handled by a procedure or something like that that I had missed.
To be honest I cannot find any articles or book chapters that are clear on the whole event, event raising and event handling business in VB.Net and I am therefore disadvantaged in terms on tracking what may be wrong.
Do you know of any good, clear ABC type type articles on events? Maybe after reading those and understanding, I may be able to solve the problem myself.
Thanks
Anyway, have run the code with a breakpoint in place and no joy. That was my first port of call, so I knew it was not the code causing an unexpected outcome.
I thought there may be a limit on the number of controls that can be handled by a procedure or something like that that I had missed.
To be honest I cannot find any articles or book chapters that are clear on the whole event, event raising and event handling business in VB.Net and I am therefore disadvantaged in terms on tracking what may be wrong.
Do you know of any good, clear ABC type type articles on events? Maybe after reading those and understanding, I may be able to solve the problem myself.
Thanks
>I thought there may be a limit on the number of controls that can be handled by a procedure or something like that that I had missed.
I'm not aware of any, and I can do 20 controls without any difficulties in a sample form.
MS suggests that you use GotFocus only for UICues, and suggests using the Enter event instead:
"Note The GotFocus and LostFocus events are low-level focus events that are tied to the WM_KILLFOCUS and WM_SETFOCUS Windows messages. Typically, the GotFocus and LostFocus events are only used when updating UICues or when writing custom controls. Instead the Enter and Leave events should be used for all controls except the Form class, which uses the Activated and Deactivate events."
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.gotfocus(VS.85).aspx
If there is something interfering with the messages being sent to the window, then you would see interference with this event (and likely with other UI features, like repainting.) Otherwise, I'm not sure what it could be. I would try the Enter event as a possible workaround.
I've used multiple controls in the "Handles" clause of the event handler before, usually with a smallish number of controls. I think when I have a large number of controls with a common event handler, I'm more likely to wire them up with an AddHandler statement. (I would be surprised if it will make a difference to your problem however.)
AddHandler Statement
http://msdn.microsoft.com/en-us/library/7taxzxka(VS.80).aspx
I'm not aware of any, and I can do 20 controls without any difficulties in a sample form.
MS suggests that you use GotFocus only for UICues, and suggests using the Enter event instead:
"Note The GotFocus and LostFocus events are low-level focus events that are tied to the WM_KILLFOCUS and WM_SETFOCUS Windows messages. Typically, the GotFocus and LostFocus events are only used when updating UICues or when writing custom controls. Instead the Enter and Leave events should be used for all controls except the Form class, which uses the Activated and Deactivate events."
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.gotfocus(VS.85).aspx
If there is something interfering with the messages being sent to the window, then you would see interference with this event (and likely with other UI features, like repainting.) Otherwise, I'm not sure what it could be. I would try the Enter event as a possible workaround.
I've used multiple controls in the "Handles" clause of the event handler before, usually with a smallish number of controls. I think when I have a large number of controls with a common event handler, I'm more likely to wire them up with an AddHandler statement. (I would be surprised if it will make a difference to your problem however.)
AddHandler Statement
http://msdn.microsoft.com/en-us/library/7taxzxka(VS.80).aspx
Premium Content
You need an Expert Office subscription to comment.Start Free Trial