I have multiple runtime generated DataGridView, and I would like to sort columns with null values. These DataGridView are bound to a Sql Server 2008 database. I have tried using the ICompare Method, which did not work because the DataGridView was bound. Is there a better option?
How does the automatic sort work? The problem with automatic sorting is that the NULL values are placed at the top of an ascending list, and I would like them to be at the bottom of the list.
The code I have tried so far is:
This code works well for a non-bound DataGridView.
I have also tried adding a column to my database, giving the column high values for Null Integers and maxdates for Null Dates for ascending, and the opposite for decending sorts, and then sorting with this column, but this does not seem to be the best way to achieve my goal.
I have also tried:
but I am not sure what event will call this procedure. I also don't think that the SortCompare method works with DataBound DataGridView.
Any ideas? I am pretty lost here...
Thanks
How does the automatic sort work? The problem with automatic sorting is that the NULL values are placed at the top of an ascending list, and I would like them to be at the bottom of the list.
The code I have tried so far is:
Code:
Private Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) _
Handles Button1.Click
If RadioButton1.Checked = True Then
DataGridView1.Sort(New RowComparer(SortOrder.Ascending))
ElseIf RadioButton2.Checked = True Then
DataGridView1.Sort(New RowComparer(SortOrder.Descending))
End If
End Sub
Private Class RowComparer
Implements System.Collections.IComparer
Private sortOrderModifier As Integer = 1
Private sortCompareModifier As Integer = 1
Public Sub New(ByVal sortOrder As SortOrder)
If sortOrder = sortOrder.Descending Then
sortOrderModifier = -1
sortCompareModifier = -1
ElseIf sortOrder = sortOrder.Ascending Then
sortOrderModifier = 1
sortOrderModifier = 1
End If
End Sub
Public Function Compare(ByVal x As Object, ByVal y As Object) As Integer _
Implements System.Collections.IComparer.Compare
Dim DataGridViewRow1 As DataGridViewRow = CType(x, DataGridViewRow)
Dim DataGridViewRow2 As DataGridViewRow = CType(y, DataGridViewRow)
Dim intCompareResult As Integer = Nothing
' Try to sort based on the Last Name column.
If DataGridViewRow1.Cells(1).Value.ToString = "" And Not DataGridViewRow2.Cells(1).Value.ToString = "" Then
intCompareResult = 1 * sortCompareModifier
ElseIf Not DataGridViewRow1.Cells(1).Value.ToString = "" And DataGridViewRow2.Cells(1).Value.ToString = "" Then
intCompareResult = -1 * sortCompareModifier
Else
intCompareResult = System.String.Compare(DataGridViewRow1.Cells(1).Value.ToString(), DataGridViewRow2.Cells(1).Value.ToString())
End If
' If the Last Names are equal, sort based on the First Name.
If intCompareResult = 0 Then
intCompareResult = System.String.Compare(DataGridViewRow1.Cells(0).Value.ToString(), DataGridViewRow2.Cells(0).Value.ToString())
End If
Return intCompareResult * sortOrderModifier
End Function
End ClassI have also tried adding a column to my database, giving the column high values for Null Integers and maxdates for Null Dates for ascending, and the opposite for decending sorts, and then sorting with this column, but this does not seem to be the best way to achieve my goal.
I have also tried:
Code:
Private Sub dgvOverview_SortCompare(sender As Object, e As System.Windows.Forms.DataGridViewSortCompareEventArgs) Handles dgvOverview.SortCompare
Dim dgv As DataGridView = sender
Dim intCheckpointNumberLength As Integer
Dim intCheckpointNumber As Integer
Dim strCheckpointName As String
If strProjectType = strCircuit Then
intCheckpointNumberLength = Len(dgv.Name) - 6
intCheckpointNumber = Microsoft.VisualBasic.Right(dgv.Name, intCheckpointNumberLength)
ElseIf strProjectType = strP2P Then
intCheckpointNumberLength = Len(dgv.Name) - 13
intCheckpointNumber = Microsoft.VisualBasic.Right(dgv.Name, intCheckpointNumberLength)
End If
strCheckpointName = "Checkpoint " & intCheckpointNumber & " "
For Each col As DataGridViewColumn In dgv.Columns
If col.Index = e.Column.Index Then
If col.Name = strCheckpointName & "Time" Then
e.SortResult = System.DateTime.Compare(SortToNull(e.CellValue1, "Time"), SortToNull(e.CellValue2, "Time"))
ElseIf col.Name.EndsWith("Position") Then
e.SortResult = System.DateTime.Compare(SortToNull(e.CellValue1, "Position"), SortToNull(e.CellValue2, "Position"))
End If
e.Handled = True
Exit Sub
End If
Next
End SubAny ideas? I am pretty lost here...
Thanks
