GetPageThumbnailAsBitmap Method

In This Topic

Creates a custom sized high quality (HQ) thumbnail of the specified page of the document displayed in the GdViewer control as a bitmap. The required page is converted to an image thumbnail that fits within a rectangle of the size and the background color you have specified.

Syntax

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

'Declaration
 
Public Function GetPageThumbnailAsBitmap( _
   ByVal Width As Integer, _
   ByVal Height As Integer, _
   ByVal Page As Integer, _
   ByVal BackColor As Color _
) As Bitmap

public Bitmap GetPageThumbnailAsBitmap( 
   int Width,
   int Height,
   int Page,
   Color BackColor
)

public function GetPageThumbnailAsBitmap( 
    Width: Integer;
    Height: Integer;
    Page: Integer;
    BackColor: Color
): Bitmap;

public function GetPageThumbnailAsBitmap( 
   Width : int,
   Height : int,
   Page : int,
   BackColor : Color
) : Bitmap;

public: Bitmap* GetPageThumbnailAsBitmap( 
   int Width,
   int Height,
   int Page,
   Color BackColor
)

public:
Bitmap^ GetPageThumbnailAsBitmap( 
   int Width,
   int Height,
   int Page,
   Color BackColor
)

Parameters

Width: The required width of the newly created thumbnail image, in pixels.
Height: The required height of the newly created thumbnail image, in pixels.
Page: The required page of the displayed document for creating the thumbnail.
BackColor: A color object that defines the background color of the thumbnail's margins. The created thumbnail image includes predefined margin on both sides painted with the specified color.

Return Value

The newly created thumbnail's image as a bitmap. Please first of all use the GetStat method to determine if this method has been successful.

Remarks

It is recommend to use the GetStat method to identify the specific reason for the method's failure, if any instead of checking the returned value.

Example

How to save the current page of the displayed document as a thumbnail in the PNG format using a bitmap.

VB.NET
C#

'We assume that the GdViewer1 control has been properly integrated.
If GdViewer1.DisplayFromFile("") = GdPictureStatus.OK Then
    Dim thumbnail As Bitmap = GdViewer1.GetPageThumbnailAsBitmap(256, 256, GdViewer1.CurrentPage, GdViewer1.ARGB(255, 180, 180, 180))
    If GdViewer1.GetStat() = GdPictureStatus.OK Then
        thumbnail.Save("thumbnail.png")
        MessageBox.Show("The created thumbnail has been saved successfully.", "GdViewer.GetPageThumbnail")
    Else
        MessageBox.Show("The thumbnail can't be created. Status: " + GdViewer1.GetStat().ToString(), "GdViewer.GetPageThumbnail")
    End If
Else
    MessageBox.Show("The file can't be loaded. Status: " + GdViewer1.GetStat().ToString(), "GdViewer.GetPageThumbnail")
End If

//We assume that the GdViewer1 control has been properly integrated.
if (GdViewer1.DisplayFromFile("") == GdPictureStatus.OK)
{
    Bitmap thumbnail = GdViewer1.GetPageThumbnailAsBitmap(256, 256, GdViewer1.CurrentPage, GdViewer1.ARGB(255, 180, 180, 180));
    if (GdViewer1.GetStat() == GdPictureStatus.OK)
    {
        thumbnail.Save("thumbnail.png");
        MessageBox.Show("The created thumbnail has been saved successfully.", "GdViewer.GetPageThumbnail");
    }
    else
        MessageBox.Show("The thumbnail can't be created. Status: " + GdViewer1.GetStat().ToString(), "GdViewer.GetPageThumbnail");
}
else
    MessageBox.Show("The file can't be loaded. Status: " + GdViewer1.GetStat().ToString(), "GdViewer.GetPageThumbnail");

Reference

GdViewer Class
GdViewer Members
GetPageThumbnail(Int32,Int32,Int32,Color) Method
ReleaseGdPictureImage Method