EnableLowMemoryUsage(Boolean,Int32,Int32) Method

'Declaration
 
Public Overloads Sub EnableLowMemoryUsage( _
   ByVal enabled As Boolean, _
   ByVal pageCount As Integer, _
   ByVal hiddenFramesCount As Integer _
) 

Private Class MedicalViewerForm : Inherits Form
      Private _medicalViewer As MedicalViewer
      Public label As Label
      Private Sub MedicalViewerForm_SizeChanged(ByVal sender As Object, ByVal e As EventArgs)
         _medicalViewer.Size = New Size(Me.ClientRectangle.Right, Me.ClientRectangle.Bottom)
      End Sub

      Public Sub New()
         Dim _codecs As RasterCodecs = New RasterCodecs()
         Dim _image As RasterImage

         AddHandler SizeChanged, AddressOf MedicalViewerForm_SizeChanged

         ' Create the medical viewer and adjust the size and the location.
         _medicalViewer = New MedicalViewer(1, 2)
         _medicalViewer.Location = New Point(0, 0)
         _medicalViewer.Size = New Size(Me.ClientRectangle.Right, Me.ClientRectangle.Bottom - 10)

         ' Load an image and then add it to the control.
         '_image = _codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "xa.dcm");
         Dim cell As MedicalViewerMultiCell = New MedicalViewerMultiCell(Nothing, True, 1, 1)
         _medicalViewer.Cells.Add(cell)

         ' add some actions that will be used to change the properties of the images inside the control.
         cell.AddAction(MedicalViewerActionType.WindowLevel)
         cell.AddAction(MedicalViewerActionType.Alpha)
         cell.AddAction(MedicalViewerActionType.Offset)

         ' assign the added actions to a mouse button, meaning that when the user clicks and drags the mouse button, the associated action will be activated.
         cell.SetAction(MedicalViewerActionType.WindowLevel, MedicalViewerMouseButtons.Left, MedicalViewerActionFlags.Active)
         cell.SetAction(MedicalViewerActionType.Alpha, MedicalViewerMouseButtons.Middle, MedicalViewerActionFlags.Active)
         cell.SetAction(MedicalViewerActionType.Offset, MedicalViewerMouseButtons.Right, MedicalViewerActionFlags.Active)

         cell.Rows = 1
         cell.Columns = 1
         cell.FitImageToCell = True

         ' adjust some properties of the cell and add some tags.
         _medicalViewer.Cells(0).SetTag(2, MedicalViewerTagAlignment.TopLeft, MedicalViewerTagType.UserData, "EX. ID 230-36-5448")
         _medicalViewer.Cells(0).SetTag(4, MedicalViewerTagAlignment.TopLeft, MedicalViewerTagType.Frame)
         _medicalViewer.Cells(0).SetTag(6, MedicalViewerTagAlignment.TopLeft, MedicalViewerTagType.Scale)
         _medicalViewer.Cells(0).SetTag(2, MedicalViewerTagAlignment.BottomLeft, MedicalViewerTagType.WindowLevelData)
         _medicalViewer.Cells(0).SetTag(1, MedicalViewerTagAlignment.BottomLeft, MedicalViewerTagType.FieldOfView)


         ' Load another image and then add it to the control.
         _image = _codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "mr.dcm"))
         _medicalViewer.Cells.Add(New MedicalViewerMultiCell(_image, True, 2, 2))

         ' add some actions that will be used to change the properties of the images inside the control.
         _medicalViewer.Cells(1).AddAction(MedicalViewerActionType.WindowLevel)
         _medicalViewer.Cells(1).AddAction(MedicalViewerActionType.Alpha)
         _medicalViewer.Cells(1).AddAction(MedicalViewerActionType.Offset)
         _medicalViewer.Cells(1).AddAction(MedicalViewerActionType.RectangleRegion)

         ' assign the added actions to a mouse button, meaning that when the user clicks and drags the mouse button, the associated action will be activated.
         _medicalViewer.Cells(1).SetAction(MedicalViewerActionType.RectangleRegion, MedicalViewerMouseButtons.Left, MedicalViewerActionFlags.Active)
         _medicalViewer.Cells(1).SetAction(MedicalViewerActionType.Alpha, MedicalViewerMouseButtons.Middle, MedicalViewerActionFlags.Active)
         _medicalViewer.Cells(1).SetAction(MedicalViewerActionType.Offset, MedicalViewerMouseButtons.Right, MedicalViewerActionFlags.Active)

         ' adjust some properties of the cell and add some tags.
         _medicalViewer.Cells(1).SetTag(2, MedicalViewerTagAlignment.TopLeft, MedicalViewerTagType.UserData, "EX. ID 230-36-5448")
         _medicalViewer.Cells(1).SetTag(4, MedicalViewerTagAlignment.TopLeft, MedicalViewerTagType.Frame)
         _medicalViewer.Cells(1).SetTag(6, MedicalViewerTagAlignment.TopLeft, MedicalViewerTagType.Scale)
         _medicalViewer.Cells(1).SetTag(2, MedicalViewerTagAlignment.BottomLeft, MedicalViewerTagType.WindowLevelData)
         _medicalViewer.Cells(1).SetTag(1, MedicalViewerTagAlignment.BottomLeft, MedicalViewerTagType.FieldOfView)

         label = New Label()
         label.Location = New Point(0, Me.ClientRectangle.Bottom - 10)
         label.Size = New Size(Me.ClientRectangle.Right, 10)
         label.Text = "Here the statistical information will appear"

         Controls.Add(_medicalViewer)
         _medicalViewer.Dock = DockStyle.Fill
      End Sub
      Public ReadOnly Property Viewer() As MedicalViewer
         Get
            Return _medicalViewer
         End Get
      End Property
   End Class

   Private Function GetMedicalControl() As MedicalViewerForm
      Return New MedicalViewerForm()
   End Function

   ' This example shows how to use the low memory usage feature to display a medical image with multiple pages. it will also invert all the bitmap to show the invert function works even if the bitmap is not loaded yet.

   Public Sub MedicalViewerLowMemoryUsageExample()
      Dim myForm As MedicalViewerForm = GetMedicalControl()
      Dim medicalViewer As MedicalViewer = myForm.Viewer
      Dim cell As MedicalViewerMultiCell = CType(medicalViewer.Cells(0), MedicalViewerMultiCell)


      Dim codecs As RasterCodecs = New RasterCodecs()
      Dim i As Integer = 0
      Dim count As Integer


      Dim info As CodecsImageInfo
      Dim fileName As String = Path.Combine(LEAD_VARS.ImagesDir, "xa.dcm")
      info = codecs.GetInformation(fileName, True)
      count = info.TotalPages
      Dim a As MedicalViewerImageInformation() = New MedicalViewerImageInformation(count - 1) {}

      i = 0
      Do While i < count
         info = codecs.GetInformation(fileName, True, i + 1)
         a(i) = New MedicalViewerImageInformation()
         a(i).ImageHeight = info.Height
         a(i).ImageWidth = info.Width
         a(i).XResolution = info.XResolution
         a(i).YResolution = info.YResolution
         i += 1
      Loop

      AddHandler cell.ActiveSubCellChanged, AddressOf medicalViewer_ActiveSubCellChanged1
      AddHandler cell.FramesRequested, AddressOf medicalViewer_FramesRequested
      cell.EnableLowMemoryUsage(2, count, a)
      myForm.ShowDialog()
   End Sub

   Private Sub medicalViewer_ActiveSubCellChanged1(ByVal sender As Object, ByVal e As MedicalViewerActiveSubCellChangedEventArgs)
      Dim imageInformation As String = ""
      Dim cell As MedicalViewerMultiCell = CType(sender, MedicalViewerMultiCell)

      If cell.VirtualImage(e.SubCellIndex).ImageExist Then
         imageInformation = "Image bit per pixel = " & cell.VirtualImage(e.SubCellIndex).Image.BitsPerPixel.ToString()
      End If

      CType(cell.ParentViewer.Parent, MedicalViewerForm).label.Text = imageInformation & " HasRegion = " & cell.VirtualImage(e.SubCellIndex).HasRegion
   End Sub

   Private Sub medicalViewer_FramesRequested(ByVal sender As Object, ByVal e As MedicalViewerRequestedFramesInformationEventArgs)
      Dim cell As MedicalViewerMultiCell = CType(sender, MedicalViewerMultiCell)
      Dim fileName As String = Path.Combine(LEAD_VARS.ImagesDir, "xa.dcm")
      Dim _codecs As RasterCodecs = New RasterCodecs()
      Dim i As Integer
      Dim b As RasterImage

      If e.RequestedFramesIndexes.Length > 0 Then
         b = _codecs.Load(fileName, 0, CodecsLoadByteOrder.BgrOrGray, e.RequestedFramesIndexes(0) + 1, e.RequestedFramesIndexes(0) + 1)
      Else
         Return
      End If

      i = 1
      Do While i < e.RequestedFramesIndexes.Length
         b.AddPage(_codecs.Load(fileName, 0, CodecsLoadByteOrder.BgrOrGray, e.RequestedFramesIndexes(i) + 1, e.RequestedFramesIndexes(i) + 1))
         i += 1
      Loop

      cell.SetRequestedImage(b, e.RequestedFramesIndexes, MedicalViewerSetImageOptions.Insert)
   End Sub


Public NotInheritable Class LEAD_VARS
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class