My ListView is populated with data from a DataSet object. The ListView isn't bound to the dataset. I loop through the dataset and create the items for the ListView. Without cell formatting, the ListView is slightly laggy. It doesn't scroll as smoothly as I think it should. There's a small bit of hesitation that I can clearly see if I try to scroll quickly.
Private Sub lvEquip_CellFormatting(sender As Object, e As ListViewCellFormattingEventArgs) 'Handles lvEquip.CellFormatting
Dim cell As DetailListViewDataCellElement = TryCast(e.CellElement, DetailListViewDataCellElement)
If cell IsNot Nothing Then
If cell.Row("Col1").ToString() IsNot Nothing Then
Dim DR As DataRow = cell.Row.Tag
Dim C As Color
Select Case e.CellElement.Data.Name
Case "Col4" 'Status
Select Case GetFromRow(DR, EquipmentCI.Status)
Case "Resolved"
C = Color.Green
Case "UnResolved"
C = Color.Red
Case "Temporary Resolution"
C = Color.Orange
End Select
e.CellElement.ForeColor = C
Case "Col5" 'Pump Stand Status
Dim ID As Integer = If(IsNumeric(GetFromRow(DR, EquipmentCI.PSStatus)), CInt(GetFromRow(DR, EquipmentCI.PSStatus)), 0)
Select Case DirectCast(ID, PSStatus)
Case PSStatus.PS
C = Color.Red
Case PSStatus.A
C = Color.Orange
Case PSStatus.R
C = Color.Green
End Select
e.CellElement.ForeColor = C
Case "Col18" 'Last PM
Dim LPM As String = GetFromRow(DR, EquipmentCI.LastPM)
Dim EH As String = GetFromRow(DR, EquipmentCI.EngineHours)
If LPM.Length < 1 Then LPM = 0
If EH.Length < 1 Then EH = 0
Dim Cnt As Integer = CInt(EH) - CInt(LPM)
If Cnt >= LastPM_High Then
C = Color.Red
ElseIf Cnt >= LastPM_Medium Then
C = Color.Orange
Else
C = Color.Green
End If
e.CellElement.ForeColor = C
Case "Col21" 'Sec Last PM
Dim LPM As String = GetFromRow(DR, EquipmentCI.SecLastPM)
Dim EH As String = GetFromRow(DR, EquipmentCI.SecEngineHours)
If LPM.Length < 1 Then LPM = 0
If EH.Length < 1 Then EH = 0
Dim Cnt As Integer = CInt(EH) - CInt(LPM)
If Cnt >= LastPM_High Then
C = Color.Red
ElseIf Cnt >= LastPM_Medium Then
C = Color.Orange
Else
C = Color.Green
End If
e.CellElement.ForeColor = C
Case "Col23" 'Fed Insp
If GetFromRow(DR, EquipmentCI.FedInsp).Length > 0 Then
Dim DT As DateTime = FMDB(GetFromRow(DR, EquipmentCI.FedInsp), False)
Dim Diff As Long = DateDiff(DateInterval.Month, DT, DateTime.Now)
If Diff >= 13 Then
C = Color.Red
ElseIf Diff >= 6 Then
C = Color.Orange
Else
C = Color.Green
End If
End If
e.CellElement.ForeColor = C
Case Else
e.CellElement.ResetValue(LightVisualElement.ForeColorProperty, ValueResetFlags.Local)
End Select
Else
e.CellElement.ResetValue(LightVisualElement.ForeColorProperty, ValueResetFlags.Local)
End If
End If
End Sub
A few key ingredients here.
FMDB: Short for FormatDateBack converts a MySQL formatted DateTime string back to a DateTime object. The boolean indicates whether I want to include the time.