PageNumber Property

C#
Visual Basic
Objective-C
Java

public int PageNumber {get; set;}

'Declaration

Public Property PageNumber As Integer

Property Value

The 1-based page number to use by this item of Image has more than one page. Default value is 0.

This value is used as the 1-based page number when a valid object is set in the Image property. RasterImage supports multi-page images (frames) and the same value can be set in multiple items. Use PageNumber to control which page is used by the item.

Note that even through the default value of 0 is not a legal page number, the item will check and internally revert to using 1 (first page).

ImageViewerPagerInteractiveMode uses the value of this property to cycle through the pages of a multi-page image in an item.

For more information, refer to Image Viewer Items.

C#
Visual Basic
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

Imports Leadtools
Imports Leadtools.Controls
Imports Leadtools.Codecs
Imports Leadtools.Drawing
Imports Leadtools.ImageProcessing
Imports Leadtools.ImageProcessing.Color

If _imageViewer.Items.Count > 0 Then
   Dim item As ImageViewerItem = _imageViewer.ActiveItem
   Dim image As RasterImage
   If Not item Is Nothing Then
      image = item.Image
   Else
      image = Nothing
   End If
   Dim pageCount As Integer
   If (Not image Is Nothing) Then
      pageCount = image.PageCount
   Else
      pageCount = 1
   End If
   If pageCount > 1 Then
      Dim oldPageNumber As Integer = item.PageNumber
      Dim newPageNumber As Integer = oldPageNumber

      If _previousItem Then
         newPageNumber -= 1
      Else
         newPageNumber += 1
      End If

      newPageNumber = Math.Max(1, Math.Min(pageCount, newPageNumber))
      If newPageNumber <> oldPageNumber Then
         item.PageNumber = newPageNumber
      End If
   Else
      Dim index As Integer = _imageViewer.Items.IndexOf(_imageViewer.ActiveItem)
      If _previousItem Then
         index -= 1
      Else
         index += 1
      End If

      If index >= 0 AndAlso index < _imageViewer.Items.Count Then
         _imageViewer.ActiveItem = _imageViewer.Items(index)
      End If
   End If
End If

using Leadtools;
using Leadtools.Controls;
using Leadtools.Codecs;
using Leadtools.Drawing;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Color;

if (_imageViewer.Items.Count > 0)
{
   var item = _imageViewer.ActiveItem;
   var image = item != null ? item.Image : null;
   var pageCount = (image != null) ? image.PageCount : 1;
   if (pageCount > 1)
   {
      var oldPageNumber = item.PageNumber;
      var newPageNumber = oldPageNumber;

      if (_previousItem)
         newPageNumber--;
      else
         newPageNumber++;

      newPageNumber = Math.Max(1, Math.Min(pageCount, newPageNumber));
      if (newPageNumber != oldPageNumber)
      {
         item.PageNumber = newPageNumber;
      }
   }
   else
   {
      var index = _imageViewer.Items.IndexOf(_imageViewer.ActiveItem);
      if (_previousItem)
         index--;
      else
         index++;

      if (index >= 0 && index < _imageViewer.Items.Count)
         _imageViewer.ActiveItem = _imageViewer.Items[index];
   }
}

Target Platforms

Reference

ImageViewerItem Class
ImageViewerItem Members