(Leadtools.Controls)

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ActiveItemプロパティ




この画像ビューワのアクティブ項目。
構文
public virtual ImageViewerItem ActiveItem {get; set;}
'Declaration
 
Public Overridable Property ActiveItem As ImageViewerItem

属性値

この画像ビューワのアクティブな項目。この値はNullにはできません
解説

詳細については、「画像ビューワの項目」を参照してください。

サンプル

単一選択がイメージのリストを有効にして、現在のアクティブな項目を追跡する方法を示すので、このサンプルはビューワを使います。

ImageViewerサンプルからサンプル関数内のコードをすべて削除し("// TODO:ここにサンプルコードを追加します"というコメントを検索する)、以下のコードを挿入します。

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

' Clear all the images already the viewer
_imageViewer.Items.Clear()
' Use vertical view layout
_imageViewer.ViewLayout = New ImageViewerVerticalViewLayout()
' Make sure the item size is larger than the image size (thumbnails mode)
_imageViewer.ItemSize = LeadSize.Create(200, 200)
_imageViewer.ImageBorderThickness = 1
' Change the active item background color
_imageViewer.ActiveItemBackgroundColor = Color.LightBlue
_imageViewer.SelectedItemBackgroundColor = Color.LightBlue
' Add 4 items to the viewer
Using codecs As New RasterCodecs()
   For page As Integer = 1 To 4
      Dim item As New ImageViewerItem()
      Dim fileName As String = Path.Combine(ImagesPath.Path, String.Format("ocr{0}.tif", page))

      ' Create a thumbnail from the image
      Using image As RasterImage = codecs.Load(fileName, page)
         item.Image = image.CreateThumbnail(180, 180, 24, RasterViewPerspective.TopLeft, RasterSizeFlags.Resample)
      End Using
      _imageViewer.Items.Add(item)
   Next page
End Using

' Add the interface mode to select items (single)
Dim selectItemsMode As New ImageViewerSelectItemsInteractiveMode()
selectItemsMode.SelectionMode = ImageViewerSelectionMode.Single
' Tell the mode to set the active item for us
selectItemsMode.AutoItemMode = ImageViewerAutoItemMode.AutoSetActive
_imageViewer.DefaultInteractiveMode = selectItemsMode

' Hook to the ActiveItemChanged event and update the label
AddHandler _imageViewer.ActiveItemChanged,
Sub(sender, e)
   Dim index As Integer = _imageViewer.Items.IndexOf(_imageViewer.ActiveItem)
   _label.Text = "ActiveIndex index is " & index.ToString()
using Leadtools;
using Leadtools.Controls;
using Leadtools.Codecs;
using Leadtools.Drawing;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Color;

// Clear all the images already the viewer
_imageViewer.Items.Clear();
// Use vertical view layout
_imageViewer.ViewLayout = new ImageViewerVerticalViewLayout();
// Make sure the item size is larger than the image size (thumbnails mode)
_imageViewer.ItemSize = LeadSize.Create(200, 200);
_imageViewer.ImageBorderThickness = 1;
// Change the active item background color
_imageViewer.ActiveItemBackgroundColor = Color.LightBlue;
_imageViewer.SelectedItemBackgroundColor = Color.LightBlue;
// Add 4 items to the viewer
using (var codecs = new RasterCodecs())
{
   for (var page = 1; page <= 4; page++)
   {
      var item = new ImageViewerItem();
      var fileName = Path.Combine(ImagesPath.Path, string.Format("ocr{0}.tif", page));

      // Create a thumbnail from the image
      using (var image = codecs.Load(fileName, page))
      {
         item.Image = image.CreateThumbnail(180, 180, 24, RasterViewPerspective.TopLeft, RasterSizeFlags.Resample);
      }
      _imageViewer.Items.Add(item);
   }
}

// Add the interface mode to select items (single)
var selectItemsMode = new ImageViewerSelectItemsInteractiveMode();
selectItemsMode.SelectionMode = ImageViewerSelectionMode.Single;
// Tell the mode to set the active item for us
selectItemsMode.AutoItemMode = ImageViewerAutoItemMode.AutoSetActive;
_imageViewer.DefaultInteractiveMode = selectItemsMode;

// Hook to the ActiveItemChanged event and update the label
_imageViewer.ActiveItemChanged += (sender, e) =>
{
   var index = _imageViewer.Items.IndexOf(_imageViewer.ActiveItem);
   _label.Text = "ActiveIndex index is " + index.ToString();
};
必要条件

ターゲットプラットホーム

参照

参照

ImageViewerクラス
ImageViewerメンバ