ZoomRect Method (GdViewer)

In This Topic

Adjusts the current zoom to the area covered by the specified rectangle of area selection. You can use the IsRect method to determine if any rectangle of selection is defined.

The control is subsequently refreshed to zoom on the determined rectangle.

Syntax

Visual Basic
C#
Delphi
JScript
Managed Extensions for C++
C++/CLI

'Declaration
 
Public Function ZoomRect() As GdPictureStatus

public GdPictureStatus ZoomRect()

public function ZoomRect(): GdPictureStatus;

public function ZoomRect() : GdPictureStatus;

public: GdPictureStatus ZoomRect();

public:
GdPictureStatus ZoomRect();

Return Value

A member of the GdPictureStatus enumeration. If the method has been successfully followed, then the return value is GdPictureStatus.OK. We strongly recommend always checking this status first.

Remarks

Be aware that if the rectangle of selection is not defined, the method will fail.

Please note that the ZoomMode property is set to ViewerZoomMode.ZoomModeCustom using this method.

Both the BeforeZoomChange and the AfterZoomChange events are raised using this method.

You can also try the Document Viewer Sample here to find out, how to utilize zooming features in your application.

Example

How to zoom to the determined rectangle of area selection.

VB.NET
C#

'We assume that the GdViewer1 control has been properly integrated.
If GdViewer1.DisplayFromFile("") = GdPictureStatus.OK Then
    Dim text_to_find As String = "GdPicture"
    GdViewer1.ClearRect()
    GdViewer1.RectIsEditable = False
    Dim text_found As Boolean = GdViewer1.SearchText(text_to_find, 1, True)
    If GdViewer1.GetStat() = GdPictureStatus.OK Then
        If text_found AndAlso GdViewer1.IsRect() Then
            GdViewer1.CenterOnRect()
            GdViewer1.ZoomRect()
        Else
            MessageBox.Show("The given text has not been found.", "GdViewer.ZoomRect")
        End If
    Else
        MessageBox.Show("The search process has failed. Status: " + GdViewer1.GetStat().ToString(), "GdViewer.ZoomRect")
    End If
Else
    MessageBox.Show("The file can't be displayed. Status: " + GdViewer1.GetStat().ToString(), "GdViewer.ZoomRect")
End If

//We assume that the GdViewer1 control has been properly integrated.
if (GdViewer1.DisplayFromFile("") == GdPictureStatus.OK)
{
    string text_to_find = "GdPicture";
    GdViewer1.ClearRect();
    GdViewer1.RectIsEditable = false;
    bool text_found = GdViewer1.SearchText(text_to_find, 1, true);
    if (GdViewer1.GetStat() == GdPictureStatus.OK)
    {
        if (text_found && GdViewer1.IsRect())
        {
            GdViewer1.CenterOnRect();
            GdViewer1.ZoomRect();
        }
        else
            MessageBox.Show("The given text has not been found.", "GdViewer.ZoomRect");
    }
    else
        MessageBox.Show("The search process has failed. Status: " + GdViewer1.GetStat().ToString(), "GdViewer.ZoomRect");
}
else
    MessageBox.Show("The file can't be displayed. Status: " + GdViewer1.GetStat().ToString(), "GdViewer.ZoomRect");

Reference

GdViewer Class
GdViewer Members
IsRect Method
ZoomArea Method
SetRectCoordinatesOnViewer Method
Zoom Property
ZoomMode Property
BeforeZoomChange Event
AfterZoomChange Event