Public Overridable Sub CenterAtPoint( _
   ByVal pt As Point _
) 

Visual Basic (Usage)	Copy Code
Dim instance As BitmapSourceViewer Dim pt As Point   instance.CenterAtPoint(pt)

public virtual void CenterAtPoint( 
   Point pt
)

public:
virtual void CenterAtPoint( 
   Point pt
) 

Parameters

pt

The point at which to center the image display, in client coordinates.

This example shows a method to change the viewer scale factor (zoom) while keeping the viewer centered.

Visual Basic

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Private Sub ZoomAndCenter(ByVal viewer As BitmapSourceViewer, 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 Rect = Rect.Intersect(New Rect(0, 0, viewer.Width, viewer.Height), viewer.PhysicalViewRectangle)         ' Get the center of what you see in physical coordinates         Dim center As System.Windows.Point = New System.Windows.Point(rc.Left + rc.Width / 2, rc.Top + rc.Height / 2)         ' Set the new scale factor         viewer.ScaleFactor = scaleFactor         ' Bring the old center into the center of the view         viewer.CenterAtPoint(center)     End If End Sub

C#

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void ZoomAndCenter(BitmapSourceViewer 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        Rect rc = Rect.Intersect(new Rect(0, 0, viewer.Width, viewer.Height), viewer.PhysicalViewRectangle);          // Get the center of what you see in physical coordinates        Point center = new Point(rc.Left + rc.Width / 2, rc.Top + rc.Height / 2);          // Set the new scale factor        viewer.ScaleFactor = scaleFactor;          // Bring the old center into the center of the view        viewer.CenterAtPoint(center);     }  }

Target Platforms: Microsoft .NET Framework 3.0, Windows XP, Windows Vista, and Windows Server 2003 family

Reference