Leadtools.WinForms Namespace > RasterImageViewer Class : CenterAtPoint Method |
'Usage Dim instance As RasterImageViewer Dim pt As Point instance.CenterAtPoint(pt)
function Leadtools.WinForms.RasterImageViewer.CenterAtPoint( pt )
Sub ZoomAndCenter(ByVal viewer As RasterImageViewer, ByVal scaleFactor As Double) ' Minimum and maximum scale factors allowed (change if you have to) Const minimumScaleFactor As Double = 0.05 Const maximumScaleFactor As Double = 11 ' Normalize the scale factor based on min and max scaleFactor = Math.Max(minimumScaleFactor, Math.Min(maximumScaleFactor, scaleFactor)) ' Check if we need to change the scale factor for the viewer If (viewer.ScaleFactor <> scaleFactor) Then ' Get the current center in logical units ' We will use this point later to re-center the viewer ' Get what you see in physical coordinates Dim rc As Rectangle = Rectangle.Intersect(viewer.PhysicalViewRectangle, viewer.ClientRectangle) ' Get the center of what you see in physical coordinates Dim center As New PointF(rc.Left + rc.Width \ 2, rc.Top + rc.Height \ 2) Dim t As New Transformer(viewer.Transform) ' Get the center of what you see in logical coordinates center = t.PointToLogical(center) ' Set the new scale factor viewer.ScaleFactor = scaleFactor ' Bring the original center into the view center t = New Transformer(viewer.Transform) ' Get the center of what you saw before the zoom in physical coordinates center = t.PointToPhysical(center) ' Bring the old center into the center of the view viewer.CenterAtPoint(Point.Round(center)) End If End Sub
void ZoomAndCenter(RasterImageViewer viewer, double scaleFactor) { // Minimum and maximum scale factors allowed (change if you have to) const double minimumScaleFactor = 0.05; const double maximumScaleFactor = 11; // Normalize the scale factor based on min and max scaleFactor = Math.Max(minimumScaleFactor, Math.Min(maximumScaleFactor, scaleFactor)); // Check if we need to change the scale factor for the viewer if(viewer.ScaleFactor != scaleFactor) { // Get the current center in logical units // We will use this point later to re-center the viewer // Get what you see in physical coordinates Rectangle rc = Rectangle.Intersect(viewer.PhysicalViewRectangle, viewer.ClientRectangle); // Get the center of what you see in physical coordinates PointF center = new PointF(rc.Left + rc.Width / 2, rc.Top + rc.Height / 2); Transformer t = new Transformer(viewer.Transform); // Get the center of what you see in logical coordinates center = t.PointToLogical(center); // Set the new scale factor viewer.ScaleFactor = scaleFactor; // Bring the original center into the view center t = new Transformer(viewer.Transform); // Get the center of what you saw before the zoom in physical coordinates center = t.PointToPhysical(center); // Bring the old center into the center of the view viewer.CenterAtPoint(Point.Round(center)); } }
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2