GdPicture.NET.14~GdPicture14.GdViewer~DisplayPreviousPage()

DisplayPreviousPage() Method

In This Topic

Syntax
Remarks
Example
See Also

Displays the previous page, if any is available, of the document currently loaded in the GdViewer control. You can use the GdViewer.CurrentPage property to determine the currently displayed page.

The GdViewer.PageDisplayed and the GdViewer.PageChanged events are raised after the page has been successfully displayed and changed.

Be aware that the GdViewer.SaveAnnotationsToPage method is called internally before each page change.

Syntax

public GdPictureStatus DisplayPreviousPage()

public function DisplayPreviousPage(): GdPictureStatus;

public function DisplayPreviousPage() : GdPictureStatus;

public: GdPictureStatus DisplayPreviousPage();

public:
GdPictureStatus DisplayPreviousPage();

'Declaration
 
Public Function DisplayPreviousPage() As GdPictureStatus

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

Please note that if no previous page is available, this method does nothing and returns GdPictureStatus.Aborted.

Just to remind you that both the GdViewer.PageDisplayed and the GdViewer.PageChanged events are raised using this method.

Example

How to introduce the page browsing feature in your viewer.

VB.NET
C#

'We assume that the GdViewer1 control has been properly integrated
'and your document has been properly displayed as well.
Enum Direction
    FirstP
    LastP
    NextP
    PreviousP
End Enum
Sub DoMove(ByVal MoveTo As Direction)
    Dim status As GdPictureStatus = GdPictureStatus.OK
    Select Case MoveTo
        Case Direction.FirstP
            status = GdViewer1.DisplayFirstPage()
        Case Direction.LastP
            status = GdViewer1.DisplayLastPage()
        Case Direction.NextP
            status = GdViewer1.DisplayNextPage()
        Case Direction.PreviousP
            status = GdViewer1.DisplayPreviousPage()
        Case Else
    End Select
    If status <> GdPictureStatus.OK Then MessageBox.Show("Failure: " + status.ToString(), "GdViewer.DisplayPreviousPage")
End Sub

//We assume that the GdViewer1 control has been properly integrated
//and your document has been properly displayed as well.
enum Direction { FirstP, LastP, NextP, PreviousP };
void DoMove(Direction MoveTo)
{
    GdPictureStatus status = GdPictureStatus.OK;
    switch (MoveTo)
    {
        case Direction.FirstP: status = GdViewer1.DisplayFirstPage(); break;
        case Direction.LastP: status = GdViewer1.DisplayLastPage(); break;
        case Direction.NextP: status = GdViewer1.DisplayNextPage(); break;
        case Direction.PreviousP: status = GdViewer1.DisplayPreviousPage(); break;
        default: break;
    }
    if (status != GdPictureStatus.OK) MessageBox.Show("Failure: " + status.ToString(), "GdViewer.DisplayPreviousPage");
}

Reference

GdViewer Class
GdViewer Members
CurrentPage Property
PageCount Property
DisplayPage Method
DisplayNextPage Method
PageChanged Event
PageDisplayed Event
SaveAnnotationsToPage Method