GdPicture.NET Reference Guide
CenterOnRect Method (GdViewer)
Example 





GdPicture14.WPF Namespace > GdViewer Class : CenterOnRect Method
Moves the current page of the document displayed in the GdViewer control within the viewer to set the rectangle of area selection, if any is defined, in the middle of the viewer. You can use the IsRect method to find out, if the rectangle of selection is currently specified.
Syntax
'Declaration
 
Public Sub CenterOnRect() 
public void CenterOnRect()
public procedure CenterOnRect(); 
public function CenterOnRect();
public: void CenterOnRect(); 
public:
void CenterOnRect(); 
Remarks
You can regularly apply the GetStat method to determine if this method has been successful.

Just to inform you, that both the horizontal and the vertical scrollbars are set to new positions, if required.

Likewise to remind you, that the current page is determined by the CurrentPage property.

Example
How to make the newly defined rectangle of selection visible in the viewer.
'We assume that the GdViewer1 control has been properly integrated
'and your document has been properly displayed as well.
If GdViewer1.SelectAllText() = GdPictureStatus.OK Then
    If GdViewer1.IsRect() Then GdViewer1.ClearRect()
    Dim regions As Rect() = GdViewer1.GetSelectedTextRegions()
    If (GdViewer1.GetStat() = GdPictureStatus.OK) AndAlso (regions.Length > 0) Then
        Dim rect As Rect = regions(0)
        GdViewer1.SetRectCoordinatesOnDocumentInch(rect.Left, rect.Top, rect.Width, rect.Height)
        GdViewer1.CenterOnRect()
    Else
        MessageBox.Show("The text region can't be found. Status: " + GdViewer1.GetStat().ToString(), "GdViewer.CenterOnRect")
    End If
Else
    MessageBox.Show("The text can't be selected. Status: " + GdViewer1.GetStat().ToString(), "GdViewer.CenterOnRect")
End If
//We assume that the GdViewer1 control has been properly integrated
//and your document has been properly displayed as well.
if (GdViewer1.SelectAllText() == GdPictureStatus.OK)
{
    if (GdViewer1.IsRect()) GdViewer1.ClearRect();
    Rect[] regions = GdViewer1.GetSelectedTextRegions();
    if ((GdViewer1.GetStat() == GdPictureStatus.OK) && (regions.Length > 0))
    {
        //The first region surely exists.
        Rect rect = regions[0];
        GdViewer1.SetRectCoordinatesOnDocumentInch(rect.Left, rect.Top, rect.Width, rect.Height);
        GdViewer1.CenterOnRect();
    }
    else
        MessageBox.Show("The text region can't be found. Status: " + GdViewer1.GetStat().ToString(), "GdViewer.CenterOnRect");
}
else
    MessageBox.Show("The text can't be selected. Status: " + GdViewer1.GetStat().ToString(), "GdViewer.CenterOnRect");
See Also

Reference

GdViewer Class
GdViewer Members
IsRect Method
ZoomRect Method
ClearRect Method
SetRectCoordinatesOnDocumentPixel Method
SetRectCoordinatesOnViewerPixel Method