DataGridView CheckBox Column (Allow only 1 selection)

Question

I have a bound DGV with 1 'static' checkbox column in which I have added through the designer. I come up with this code to allow for only 1 row to be checked.

    Private Sub EmpGrid_CellContentClick(sender As Object, e As DataGridViewCellEventArgs) Handles EmpGrid.CellContentClick
        Dim RowIndex As Integer = EmpGrid.CurrentRow.Index
        For Each row As DataGridViewRow In EmpGrid.Rows
            If Not row.Index = RowIndex Then
                row.Cells("SelCol").Value = False
            End If
        Next
    End Sub

When clicking on a chkbox for the first time it hangs for a few seconds, but after a box has already been checked, and after the short hang, it works as expected and no more hanging. 

Any Ideas?

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Live as if you were going to die today, learn as if you were going to live forever.

Answer 1

Checking if the value is true before changing it to false has eliminated the short delay.

            If Not row.Index = RowIndex Then
                If row.Cells("selcol").Value = True Then row.Cells("SelCol").Value = False
            End If

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Live as if you were going to die today, learn as if you were going to live forever.

Answer 2

There's no need to loop through every row.  Set a module level variable to the current row index and initialise it at -1.  Then you can clear the currently checked row without looping.

   Dim CheckedRowIndex As Integer = -1
   Private Sub EmpGrid_CellContentClick(sender As Object, e As DataGridViewCellEventArgs) Handles EmpGrid.CellContentClick
      If CheckedRowIndex > -1 Then
         EmpGrid("SelCol", CheckedRowIndex).Value = False
      End If
      CheckedRowIndex = e.RowIndex
   End Sub

Answer 3

I see what you mean, your code is much more efficient.

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Live as if you were going to die today, learn as if you were going to live forever.

Answer 4

Checking if the value is true before changing it to false has eliminated the short delay.

            If Not row.Index = RowIndex Then
                If row.Cells("selcol").Value = True Then row.Cells("SelCol").Value = False
            End If

For the record. I am not real sure why, but I was getting varied results using this, until I converted the cell value to boolean.

If Convert.ToBoolean(row.Cells("selcol").Value) = True Then row.Cells("SelCol").Value = False

Think I will adopt Daves method...

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Live as if you were going to die today, learn as if you were going to live forever.