Bindings appear lost after changes are cancelled

[Ron L]

All

I am working with a DataGrid and a form consisting of a number of text,
checkbox, combobox controls, all bound to the same datatable. When I click
on my "New" button, I create a new row, make it the current row, and allow
the user to make changes in the form. If the user desires to cancel, they
can click the "Cancel Changes" button. Here is where my problems start.
Once the Cancel Changes button is clicked, the bindings on the form appear
to be permanently lost until I close and re-open the form. I have attached
the relevant portions of the New and Cancel button Click Event routines as
well as a representative portion of the binding initializations . Note that
I only bind the controls at form startup.

Can anyone tell me what I am doing wrong here?

TIA
Ron L

Private Sub BtnNew_Click(By Val sender As System.Object, ByVal e As
System.EventArg s) _
Handles _btnNew.Click
....
' Create a new row in the data table and change the List Tab's
filter so that the new row is the selected item
Dim dt As DataTable = CType(_ppdctlr. ListGrid.DataSo urce, DataTable)
Dim dr As DataRow = dt.NewRow
dr.Item("PPDID" ) = "NewPPD"
dt.Rows.Add(dr)
CType(cm.List, DataView).RowFi lter = "PPDID = 'NewPPD'"
....
End Sub

Private Sub CancelChanges(B yVal sender As System.Object, ByVal e As
System.EventArg s) _
Handles _btnCancel.Clic k
Dim cm As CurrencyManager
Dim drv, newRow As DataRowView
Dim permLevel As Integer

Dim dt As DataTable = CType(_ppdctlr. ListGrid.DataSo urce, DataTable)
dt.RejectChange s()
' reset the previously selected ID.
_listCtlr.SetCu rrentRow(_listS electedID)
drv = CType(cm.List,
DataView).Item( _ppdctlr.ListGr id.CurrentRowIn dex)
permLevel = PermissionLevel (drv)
....
End Sub

Private Sub BindUserControl s()
Dim dt As DataTable = _ppdctlr.ListGr id.DataSource

_txtPPDID.DataB indings.Add("te xt", dt, "PPDID")
_txtGlobalID.Da taBindings.Add( "text", dt, "GlobalID")
_txtDuplicateOf .DataBindings.A dd("text", dt, "DuplicateO f")
_txtCPRRequestS ubmitted.DataBi ndings.Add("tex t", dt,
"CPRRequestedDa te")
_cbCPRRequired. DataBindings.Ad d("Checked", dt, "CPRRequire d")
_cbDPRRequired. DataBindings.Ad d("Checked", dt, "DPRRequire d")
_txtTitle.DataB indings.Add("te xt", dt, "Title")
_txtModDate.Dat aBindings.Add(" text", dt, "ModifiedDa te")
_cboType.DataBi ndings.Add("tex t", dt, "Type")
_cboProblemArea .DataBindings.A dd("text", dt, "ProblemAre a")
....
End Sub

[Cor Ligthert [MVP]]

Ron,

I don't see direct the error, however does this work.

Private Sub CancelChanges(B yVal sender As System.Object, ByVal e As
System.EventArg s) _
Handles _btnCancel.Clic k
Dim cm As CurrencyManager
Dim drv, newRow As DataRowView
Dim permLevel As Integer

Dim dt As DataTable = CType(_ppdctlr. ListGrid.DataSo urce,
DataTable)
dt.RejectChange s()
' reset the previously selected ID.
_listCtlr.SetCu rrentRow(_listS electedID)
drv = CType(cm.List,
DataView).Item( _ppdctlr.ListGr id.CurrentRowIn dex)

That cm (currencymanage r is just an address in my opinon without any
reference in it).

Cor

[Ron L]

Cor

Thanks for the response. My Bad, the assignment to cm was in the code I cut
for clarity. The following line is in my code just after the
dt.RejectChange s line:

cm =
CType(_ppdctlr. ListGrid.Bindin gContext(CType( _ppdctlr.ListGr id.DataSource,
DataTable)), CurrencyManager )

Basically, my problem appears to be that the bindings are lost when the
changes are cancelled.

Ron L
"Cor Ligthert [MVP]" <no************ @planet.nl> wrote in message
news:Ow******** ******@TK2MSFTN GP14.phx.gbl...

Ron,

I don't see direct the error, however does this work.

Private Sub CancelChanges(B yVal sender As System.Object, ByVal e As
System.EventArg s) _
Handles _btnCancel.Clic k
Dim cm As CurrencyManager
Dim drv, newRow As DataRowView
Dim permLevel As Integer

Dim dt As DataTable = CType(_ppdctlr. ListGrid.DataSo urce,
DataTable)
dt.RejectChange s()
' reset the previously selected ID.
_listCtlr.SetCu rrentRow(_listS electedID)
drv = CType(cm.List,
DataView).Item( _ppdctlr.ListGr id.CurrentRowIn dex)

That cm (currencymanage r is just an address in my opinon without any
reference in it).

Cor

[Bart Mermuys]

Hi,

"Ron L" <ro**@bogus.Add ress.com> wrote in message
news:es******** ******@TK2MSFTN GP14.phx.gbl...

All

I am working with a DataGrid and a form consisting of a number of text,
checkbox, combobox controls, all bound to the same datatable. When I
click on my "New" button, I create a new row, make it the current row, and
allow the user to make changes in the form. If the user desires to
cancel, they can click the "Cancel Changes" button. Here is where my
problems start. Once the Cancel Changes button is clicked, the bindings on
the form appear to be permanently lost until I close and re-open the form.
I have attached the relevant portions of the New and Cancel button Click
Event routines as well as a representative portion of the binding
initializations . Note that I only bind the controls at form startup.

Can anyone tell me what I am doing wrong here?
Did you already set default values for the fields that are bound to
CheckBox, CheckBox can't handle null values (common for new rows) and may
crash the binding, eg.:

dt.Columns( "DPRRequired"). DefaultValue = false
dt.Columns( "CPRRequired"). DefaultValue = false

Instead you could probely also set the default values after you create the
new row (dt.NewRow), *but* before you add it to the Rows collection.

I know you are not using CurrencyManager .AddNew but the problem with
CheckBox is described here:
http://support.microsoft.com/default...b;en-us;326440
hth,
greetings


TIA
Ron L

Private Sub BtnNew_Click(By Val sender As System.Object, ByVal e As
System.EventArg s) _
Handles _btnNew.Click
...
' Create a new row in the data table and change the List Tab's
filter so that the new row is the selected item
Dim dt As DataTable = CType(_ppdctlr. ListGrid.DataSo urce,
DataTable)
Dim dr As DataRow = dt.NewRow
dr.Item("PPDID" ) = "NewPPD"
dt.Rows.Add(dr)
CType(cm.List, DataView).RowFi lter = "PPDID = 'NewPPD'"
...
End Sub

Private Sub CancelChanges(B yVal sender As System.Object, ByVal e As
System.EventArg s) _
Handles _btnCancel.Clic k
Dim cm As CurrencyManager
Dim drv, newRow As DataRowView
Dim permLevel As Integer

Dim dt As DataTable = CType(_ppdctlr. ListGrid.DataSo urce,
DataTable)
dt.RejectChange s()
' reset the previously selected ID.
_listCtlr.SetCu rrentRow(_listS electedID)
drv = CType(cm.List,
DataView).Item( _ppdctlr.ListGr id.CurrentRowIn dex)
permLevel = PermissionLevel (drv)
...
End Sub

Private Sub BindUserControl s()
Dim dt As DataTable = _ppdctlr.ListGr id.DataSource

_txtPPDID.DataB indings.Add("te xt", dt, "PPDID")
_txtGlobalID.Da taBindings.Add( "text", dt, "GlobalID")
_txtDuplicateOf .DataBindings.A dd("text", dt, "DuplicateO f")
_txtCPRRequestS ubmitted.DataBi ndings.Add("tex t", dt,
"CPRRequestedDa te")
_cbCPRRequired. DataBindings.Ad d("Checked", dt, "CPRRequire d")
_cbDPRRequired. DataBindings.Ad d("Checked", dt, "DPRRequire d")
_txtTitle.DataB indings.Add("te xt", dt, "Title")
_txtModDate.Dat aBindings.Add(" text", dt, "ModifiedDa te")
_cboType.DataBi ndings.Add("tex t", dt, "Type")
_cboProblemArea .DataBindings.A dd("text", dt, "ProblemAre a")
...
End Sub

[Ron L]

Bart

Thanks for the response. I will give that a try.

Ron L

"Bart Mermuys" <bm************ *@hotmail.com> wrote in message
news:%2******** *******@TK2MSFT NGP15.phx.gbl.. .

Hi,

"Ron L" <ro**@bogus.Add ress.com> wrote in message
news:es******** ******@TK2MSFTN GP14.phx.gbl...

All

I am working with a DataGrid and a form consisting of a number of text,
checkbox, combobox controls, all bound to the same datatable. When I
click on my "New" button, I create a new row, make it the current row,
and allow the user to make changes in the form. If the user desires to
cancel, they can click the "Cancel Changes" button. Here is where my
problems start. Once the Cancel Changes button is clicked, the bindings
on the form appear to be permanently lost until I close and re-open the
form. I have attached the relevant portions of the New and Cancel button
Click Event routines as well as a representative portion of the binding
initializations . Note that I only bind the controls at form startup.

Can anyone tell me what I am doing wrong here?

Did you already set default values for the fields that are bound to
CheckBox, CheckBox can't handle null values (common for new rows) and may
crash the binding, eg.:

dt.Columns( "DPRRequired"). DefaultValue = false
dt.Columns( "CPRRequired"). DefaultValue = false

Instead you could probely also set the default values after you create the
new row (dt.NewRow), *but* before you add it to the Rows collection.

I know you are not using CurrencyManager .AddNew but the problem with
CheckBox is described here:
http://support.microsoft.com/default...b;en-us;326440
hth,
greetings

TIA
Ron L

Private Sub BtnNew_Click(By Val sender As System.Object, ByVal e As
System.EventArg s) _
Handles _btnNew.Click
...
' Create a new row in the data table and change the List Tab's
filter so that the new row is the selected item
Dim dt As DataTable = CType(_ppdctlr. ListGrid.DataSo urce,
DataTable)
Dim dr As DataRow = dt.NewRow
dr.Item("PPDID" ) = "NewPPD"
dt.Rows.Add(dr)
CType(cm.List, DataView).RowFi lter = "PPDID = 'NewPPD'"
...
End Sub

Private Sub CancelChanges(B yVal sender As System.Object, ByVal e As
System.EventArg s) _
Handles _btnCancel.Clic k
Dim cm As CurrencyManager
Dim drv, newRow As DataRowView
Dim permLevel As Integer

Dim dt As DataTable = CType(_ppdctlr. ListGrid.DataSo urce,
DataTable)
dt.RejectChange s()
' reset the previously selected ID.
_listCtlr.SetCu rrentRow(_listS electedID)
drv = CType(cm.List,
DataView).Item( _ppdctlr.ListGr id.CurrentRowIn dex)
permLevel = PermissionLevel (drv)
...
End Sub

Private Sub BindUserControl s()
Dim dt As DataTable = _ppdctlr.ListGr id.DataSource

_txtPPDID.DataB indings.Add("te xt", dt, "PPDID")
_txtGlobalID.Da taBindings.Add( "text", dt, "GlobalID")
_txtDuplicateOf .DataBindings.A dd("text", dt, "DuplicateO f")
_txtCPRRequestS ubmitted.DataBi ndings.Add("tex t", dt,
"CPRRequestedDa te")
_cbCPRRequired. DataBindings.Ad d("Checked", dt, "CPRRequire d")
_cbDPRRequired. DataBindings.Ad d("Checked", dt, "DPRRequire d")
_txtTitle.DataB indings.Add("te xt", dt, "Title")
_txtModDate.Dat aBindings.Add(" text", dt, "ModifiedDa te")
_cboType.DataBi ndings.Add("tex t", dt, "Type")
_cboProblemArea .DataBindings.A dd("text", dt, "ProblemAre a")
...
End Sub

[Cor Ligthert [MVP]]

Ron,

May I try to make it for me more clearer.

You add a datarow.
That is in the table the row
dt.rows(count-1)

I would in this remove or delete that datarow again when it is canceled,
what is in this action the same because it is an added row.

Cor

[Cor Ligthert [MVP]]

The same is that delete or remove in this case. A little bit unclear when I
have read it back.

[Ron L]

Cor

I have tried using both the .RejectChanges method and row.Delete method, and
both have the same effect - my form's fields are empty and won't bind when
another row is selected in the list.

Ron L
"Cor Ligthert [MVP]" <no************ @planet.nl> wrote in message
news:eO******** *****@TK2MSFTNG P12.phx.gbl...

The same is that delete or remove in this case. A little bit unclear when
I have read it back.

[Ron L]

Bart

Thanks for the thought, but that was apparently not the problem. I put in
the DefaultValues on each of those columns and still have the same results.

Ron L

"Bart Mermuys" <bm************ *@hotmail.com> wrote in message
news:%2******** *******@TK2MSFT NGP15.phx.gbl.. .

Hi,

"Ron L" <ro**@bogus.Add ress.com> wrote in message
news:es******** ******@TK2MSFTN GP14.phx.gbl...

All

I am working with a DataGrid and a form consisting of a number of text,
checkbox, combobox controls, all bound to the same datatable. When I
click on my "New" button, I create a new row, make it the current row,
and allow the user to make changes in the form. If the user desires to
cancel, they can click the "Cancel Changes" button. Here is where my
problems start. Once the Cancel Changes button is clicked, the bindings
on the form appear to be permanently lost until I close and re-open the
form. I have attached the relevant portions of the New and Cancel button
Click Event routines as well as a representative portion of the binding
initializations . Note that I only bind the controls at form startup.

Can anyone tell me what I am doing wrong here?

Did you already set default values for the fields that are bound to
CheckBox, CheckBox can't handle null values (common for new rows) and may
crash the binding, eg.:

dt.Columns( "DPRRequired"). DefaultValue = false
dt.Columns( "CPRRequired"). DefaultValue = false

Instead you could probely also set the default values after you create the
new row (dt.NewRow), *but* before you add it to the Rows collection.

I know you are not using CurrencyManager .AddNew but the problem with
CheckBox is described here:
http://support.microsoft.com/default...b;en-us;326440
hth,
greetings

TIA
Ron L

Private Sub BtnNew_Click(By Val sender As System.Object, ByVal e As
System.EventArg s) _
Handles _btnNew.Click
...
' Create a new row in the data table and change the List Tab's
filter so that the new row is the selected item
Dim dt As DataTable = CType(_ppdctlr. ListGrid.DataSo urce,
DataTable)
Dim dr As DataRow = dt.NewRow
dr.Item("PPDID" ) = "NewPPD"
dt.Rows.Add(dr)
CType(cm.List, DataView).RowFi lter = "PPDID = 'NewPPD'"
...
End Sub

Private Sub CancelChanges(B yVal sender As System.Object, ByVal e As
System.EventArg s) _
Handles _btnCancel.Clic k
Dim cm As CurrencyManager
Dim drv, newRow As DataRowView
Dim permLevel As Integer

Dim dt As DataTable = CType(_ppdctlr. ListGrid.DataSo urce,
DataTable)
dt.RejectChange s()
' reset the previously selected ID.
_listCtlr.SetCu rrentRow(_listS electedID)
drv = CType(cm.List,
DataView).Item( _ppdctlr.ListGr id.CurrentRowIn dex)
permLevel = PermissionLevel (drv)
...
End Sub

Private Sub BindUserControl s()
Dim dt As DataTable = _ppdctlr.ListGr id.DataSource

_txtPPDID.DataB indings.Add("te xt", dt, "PPDID")
_txtGlobalID.Da taBindings.Add( "text", dt, "GlobalID")
_txtDuplicateOf .DataBindings.A dd("text", dt, "DuplicateO f")
_txtCPRRequestS ubmitted.DataBi ndings.Add("tex t", dt,
"CPRRequestedDa te")
_cbCPRRequired. DataBindings.Ad d("Checked", dt, "CPRRequire d")
_cbDPRRequired. DataBindings.Ad d("Checked", dt, "DPRRequire d")
_txtTitle.DataB indings.Add("te xt", dt, "Title")
_txtModDate.Dat aBindings.Add(" text", dt, "ModifiedDa te")
_cboType.DataBi ndings.Add("tex t", dt, "Type")
_cboProblemArea .DataBindings.A dd("text", dt, "ProblemAre a")
...
End Sub

[Miha Markic [MVP C#]]

Hi Ron,

What exactly do you mean by bindings are lost?
You can't create new rows?

Do you realize that calling dt.RejectChange s will remove all rows that
aren't yet stored in database (DataRowState.A dded) and cancel all other
changes?
Is this the answer?

--
Miha Markic [MVP C#]
RightHand .NET consulting & development www.rthand.com
Blog: http://cs.rthand.com/blogs/blog_with_righthand/

"Ron L" <ro**@bogus.Add ress.com> wrote in message
news:es******** ******@TK2MSFTN GP14.phx.gbl...

All

I am working with a DataGrid and a form consisting of a number of text,
checkbox, combobox controls, all bound to the same datatable. When I
click on my "New" button, I create a new row, make it the current row, and
allow the user to make changes in the form. If the user desires to
cancel, they can click the "Cancel Changes" button. Here is where my
problems start. Once the Cancel Changes button is clicked, the bindings on
the form appear to be permanently lost until I close and re-open the form.
I have attached the relevant portions of the New and Cancel button Click
Event routines as well as a representative portion of the binding
initializations . Note that I only bind the controls at form startup.

Can anyone tell me what I am doing wrong here?

TIA
Ron L

Private Sub BtnNew_Click(By Val sender As System.Object, ByVal e As
System.EventArg s) _
Handles _btnNew.Click
...
' Create a new row in the data table and change the List Tab's
filter so that the new row is the selected item
Dim dt As DataTable = CType(_ppdctlr. ListGrid.DataSo urce,
DataTable)
Dim dr As DataRow = dt.NewRow
dr.Item("PPDID" ) = "NewPPD"
dt.Rows.Add(dr)
CType(cm.List, DataView).RowFi lter = "PPDID = 'NewPPD'"
...
End Sub

Private Sub CancelChanges(B yVal sender As System.Object, ByVal e As
System.EventArg s) _
Handles _btnCancel.Clic k
Dim cm As CurrencyManager
Dim drv, newRow As DataRowView
Dim permLevel As Integer

Dim dt As DataTable = CType(_ppdctlr. ListGrid.DataSo urce,
DataTable)
dt.RejectChange s()
' reset the previously selected ID.
_listCtlr.SetCu rrentRow(_listS electedID)
drv = CType(cm.List,
DataView).Item( _ppdctlr.ListGr id.CurrentRowIn dex)
permLevel = PermissionLevel (drv)
...
End Sub

Private Sub BindUserControl s()
Dim dt As DataTable = _ppdctlr.ListGr id.DataSource

_txtPPDID.DataB indings.Add("te xt", dt, "PPDID")
_txtGlobalID.Da taBindings.Add( "text", dt, "GlobalID")
_txtDuplicateOf .DataBindings.A dd("text", dt, "DuplicateO f")
_txtCPRRequestS ubmitted.DataBi ndings.Add("tex t", dt,
"CPRRequestedDa te")
_cbCPRRequired. DataBindings.Ad d("Checked", dt, "CPRRequire d")
_cbDPRRequired. DataBindings.Ad d("Checked", dt, "DPRRequire d")
_txtTitle.DataB indings.Add("te xt", dt, "Title")
_txtModDate.Dat aBindings.Add(" text", dt, "ModifiedDa te")
_cboType.DataBi ndings.Add("tex t", dt, "Type")
_cboProblemArea .DataBindings.A dd("text", dt, "ProblemAre a")
...
End Sub