need algorithm to make sure only one datagrid row is checked

[Brian Link]

I have a column called "DefaultYN" in a resultset. It appears as a
boolColumn.

What I'd like to do is to ensure that only one row at a time can be
selected as the "Default" row. Unfortunately, I can't figure out

1. How to figure out that the checkbox has been checked
2. How to check the other rows to see if they're checked

Should I do this with the grid itself? Or with the underlying
datasource? The grid is bound to a datatable object.

Thanks for any info.

Brian Link, Minnesota Countertenor
- - - - - - - - - - - - - - - - -
"Mother, people only invite you to dinner for
three reasons: to sell you vitamins, to drug you
and take unpleasant snapshots, or to convert you
to their hideous farming religion."

[Cor]

Hi Brian,

I think that if this was my problem I would save the place of the last
checked checkbox and unchecked that when there becomes another one.

I hope this helps?

Cor

[Cor]

Hi Brian,

I think that if this was my problem I would save the place of the last
checked checkbox and unchecked that when there becomes another one.

I hope this helps?

Cor

[Brian Link]

On Sun, 4 Apr 2004 08:46:07 +0200, "Cor" <no*@non.com> wrote:

Hi Brian,

I think that if this was my problem I would save the place of the last
checked checkbox and unchecked that when there becomes another one.

I hope this helps?

Cor

That's a good idea - but how to detect when a checkbox has been
checked?

BLink

[Brian Link]

On Sun, 4 Apr 2004 08:46:07 +0200, "Cor" <no*@non.com> wrote:

Hi Brian,

I think that if this was my problem I would save the place of the last
checked checkbox and unchecked that when there becomes another one.

I hope this helps?

Cor

That's a good idea - but how to detect when a checkbox has been
checked?

BLink

[Peter Huang]

Hi Brian,

First of all, I would like to confirm my understanding of your issue.
From your description, I understand that you wants to detect if a checked
box in the datagrid which is a boolean column has been checked.
Have I fully understood you? If there is anything I misunderstood, please
feel free to let me know.

That is to say, the table will be checked, the value in the according
column will be true otherwise will be false.

I think you may try to use the Item property of datagrid.
Me.DataGrid1.Item(rows,cols).tostring()
[Note: the rows and cols are zero-based]

Also if you you have binding the datagrid onto a dataset or datatable, you
can retrieve the status from underlying datatable directly.

Please apply my suggestion above and let me know if it helps resolve your
problem.
Best regards,

Peter Huang
Microsoft Online Partner Support

Get Secure! - www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.

[Peter Huang]

Hi Brian,

First of all, I would like to confirm my understanding of your issue.
From your description, I understand that you wants to detect if a checked
box in the datagrid which is a boolean column has been checked.
Have I fully understood you? If there is anything I misunderstood, please
feel free to let me know.

That is to say, the table will be checked, the value in the according
column will be true otherwise will be false.

I think you may try to use the Item property of datagrid.
Me.DataGrid1.Item(rows,cols).tostring()
[Note: the rows and cols are zero-based]

Also if you you have binding the datagrid onto a dataset or datatable, you
can retrieve the status from underlying datatable directly.

Please apply my suggestion above and let me know if it helps resolve your
problem.
Best regards,

Peter Huang
Microsoft Online Partner Support

Get Secure! - www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.

[Brian Link]

On Mon, 05 Apr 2004 06:47:51 GMT, v-******@online.microsoft.com
("Peter Huang") wrote:

Hi Brian,

First of all, I would like to confirm my understanding of your issue.
From your description, I understand that you wants to detect if a checked
box in the datagrid which is a boolean column has been checked.
Have I fully understood you? If there is anything I misunderstood, please
feel free to let me know.

That is to say, the table will be checked, the value in the according
column will be true otherwise will be false.

I think you may try to use the Item property of datagrid.
Me.DataGrid1.Item(rows,cols).tostring()
[Note: the rows and cols are zero-based]

Also if you you have binding the datagrid onto a dataset or datatable, you
can retrieve the status from underlying datatable directly.

Please apply my suggestion above and let me know if it helps resolve your
problem.
Best regards,

Peter Huang
Microsoft Online Partner Support

Get Secure! - www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.

Thank you Peter - that answers part of my question.

The only other thing I need is a "Check" event on the datagrid. In
other words, where can I trap the click which checks or unchecks the
checkbox? This would be the event where I would evaluate its state,
and reset the other checkboxes accordingly.

Thanks

BLink

[Brian Link]

On Mon, 05 Apr 2004 06:47:51 GMT, v-******@online.microsoft.com
("Peter Huang") wrote:

Hi Brian,

First of all, I would like to confirm my understanding of your issue.
From your description, I understand that you wants to detect if a checked
box in the datagrid which is a boolean column has been checked.
Have I fully understood you? If there is anything I misunderstood, please
feel free to let me know.

That is to say, the table will be checked, the value in the according
column will be true otherwise will be false.

I think you may try to use the Item property of datagrid.
Me.DataGrid1.Item(rows,cols).tostring()
[Note: the rows and cols are zero-based]

Also if you you have binding the datagrid onto a dataset or datatable, you
can retrieve the status from underlying datatable directly.

Please apply my suggestion above and let me know if it helps resolve your
problem.
Best regards,

Peter Huang
Microsoft Online Partner Support

Get Secure! - www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.

Thank you Peter - that answers part of my question.

The only other thing I need is a "Check" event on the datagrid. In
other words, where can I trap the click which checks or unchecks the
checkbox? This would be the event where I would evaluate its state,
and reset the other checkboxes accordingly.

Thanks

BLink

[Peter Huang]

Hi Brian,

Based on my experience, I think there is no such event that will fired when
the value of the CheckedBox si changed.
Because when changed the value in the table, the RowChanged event of Table
will be fired until we move the focus onto another row, but this is not the
behavior we need here.

So I think we can try to handle the PositionChanged of CurrencyManager to
handle the checked state.

Here goes the code, you may have a try and let me know the result.

Dim WithEvents myCurrencyManager As CurrencyManager
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
Me.SqlDataAdapter1.Fill(Me.DataSet11)
myCurrencyManager = CType(Me.DataGrid1.BindingContext(Me.DataSet11,
"TestTable"), CurrencyManager)
myCurrencyManager.Position = 0
Me.DataSet11.TestTable.Rows(0).Item("Checked") = True
End Sub

Private Sub myCurrencyManager_PositionChanged(ByVal sender As Object,
ByVal e As System.EventArgs) Handles myCurrencyManager.PositionChanged
Try
Me.DataSet11.TestTable.Select("Checked = 1")(0).Item("Checked")
= False
Me.DataSet11.TestTable.Select("ID = " +
Me.DataGrid1(myCurrencyManager.Position, 0).ToString())(0).Item("Checked")
= True
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Best regards,

Peter Huang
Microsoft Online Partner Support

Get Secure! - www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.

[Peter Huang]

Hi Brian,

Based on my experience, I think there is no such event that will fired when
the value of the CheckedBox si changed.
Because when changed the value in the table, the RowChanged event of Table
will be fired until we move the focus onto another row, but this is not the
behavior we need here.

So I think we can try to handle the PositionChanged of CurrencyManager to
handle the checked state.

Here goes the code, you may have a try and let me know the result.

Dim WithEvents myCurrencyManager As CurrencyManager
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
Me.SqlDataAdapter1.Fill(Me.DataSet11)
myCurrencyManager = CType(Me.DataGrid1.BindingContext(Me.DataSet11,
"TestTable"), CurrencyManager)
myCurrencyManager.Position = 0
Me.DataSet11.TestTable.Rows(0).Item("Checked") = True
End Sub

Private Sub myCurrencyManager_PositionChanged(ByVal sender As Object,
ByVal e As System.EventArgs) Handles myCurrencyManager.PositionChanged
Try
Me.DataSet11.TestTable.Select("Checked = 1")(0).Item("Checked")
= False
Me.DataSet11.TestTable.Select("ID = " +
Me.DataGrid1(myCurrencyManager.Position, 0).ToString())(0).Item("Checked")
= True
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Best regards,

Peter Huang
Microsoft Online Partner Support

Get Secure! - www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.