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Image Property

Summary

The image associated with this RasterImageListItem object.

Syntax

C++/CLI

C++

public RasterImage Image { get; set; }

public: 
property RasterImage^ Image { 
   RasterImage^ get(); 
   void set (    RasterImage^ ); 
}

public:  
   property RasterImage^ Image 
   { 
      RasterImage^ get() 
      void set(RasterImage^ value) 
   }

Property Value

An Leadtools.RasterImage object associated with this RasterImageListItem object. The default value is null (Nothing in VB).

Remarks

The Page property specifies the 1-based page number to view from this image.

The value of RasterImage.Page is not used to control the page number of the item to be viewed in this item. Instead, use the Page property. This allows the same Leadtools.RasterImage object to be used multiple items while setting the Page property to different values.

The RasterImageList control will paint this image onto the item surface. If the item does not have an image, the value of this property is null (Nothing in VB) and, nothing is painted.

The RasterImageList control paints the image in the following manner:

If the image size is less than or equal to the ItemImageSize value, the image is painted with its original size only centered onto the item surface.
If the image size is grater than the ItemImageSize value, the image is stretched to this smaller size and the aspect ratio is kept the same.
It is recommended that you populate the items with "thumbnail" images. This will increase the performance of the item painting operation. In such cases, use the Tag or FileName properties to store the information needed to load the image in its original size when requested.

The value of RasterImage.Page is not used to control the page number of the item to be viewed in this item. Instead, use the Page property. This allows the same Leadtools.RasterImage object to be used in multiple items while setting the Page property to different values.

Example

using Leadtools.WinForms; 
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Drawing; 
 
class MyForm2 : Form 
{ 
   RasterImageViewer viewer; 
   RasterImageList imageList; 
   RasterCodecs codecs; 
 
   public MyForm2() 
   { 
      // Set the size of the form 
      Size = new Size(400, 200); 
 
      // Create a new RasterImageList control 
      imageList = new RasterImageList(); 
      imageList.Dock = DockStyle.Left; 
      imageList.SelectionMode = RasterImageListSelectionMode.Single; 
      Controls.Add(imageList); 
      imageList.BringToFront(); 
 
      // Add a handler to the SelectedIndexChanged event 
      imageList.SelectedIndexChanged += new EventHandler(rasterImageList_SelectedIndexChanged); 
 
      Splitter splitter = new Splitter(); 
      splitter.Dock = DockStyle.Left; 
      Controls.Add(splitter); 
      splitter.BringToFront(); 
 
      viewer = new RasterImageViewer(); 
      viewer.Dock = DockStyle.Fill; 
      Controls.Add(viewer); 
      viewer.BringToFront(); 
 
      // Now load all our images 
      codecs = new RasterCodecs(); 
 
      string folderName = LEAD_VARS.ImagesDir; 
      string[] files = Directory.GetFiles(folderName, "*.*"); 
 
      // This is going to be a lengthy operation 
      // Suspend painting the RasterImageList 
      imageList.BeginUpdate(); 
 
      foreach (string fileName in files) 
      { 
         // Load the image as a thumbnail 
         RasterImage image = LoadThumbnail(fileName); 
 
         // Only add an item if we loaded the image successfuly 
         if (image != null) 
         { 
            // Create an item 
            RasterImageListItem item = new RasterImageListItem(); 
 
 
            // Setup the item information 
            item.Image = image; 
            item.Text = Path.GetFileName(fileName); 
            item.Page = 1; 
 
            // To load this image in original size later 
            item.FileName = fileName; 
 
            // Add the item into RasterImageList 
            imageList.Items.Add(item); 
         } 
      } 
 
      imageList.EndUpdate(); 
 
   } 
 
   private void rasterImageList_SelectedIndexChanged(object sender, EventArgs e) 
   { 
      // User has selected an item from the RasterImageList control. 
      // Re-load the item image and show it in original size in the viewer 
 
      // Get the selected item(s) 
      RasterImageListItemCollection selectedItems = imageList.SelectedItems; 
      if (selectedItems != null && selectedItems.Count == 1) 
      { 
         RasterImageListItem item = selectedItems[0]; 
 
         // Load the image in its original size and set it in the viewer 
         viewer.Image = codecs.Load( 
            item.FileName, 
            0, 
            CodecsLoadByteOrder.BgrOrGray, 
            1, 
            1); 
      } 
   } 
 
   private RasterImage LoadThumbnail(string fileName) 
   { 
      RasterImage image = null; 
 
      try 
      { 
         // See if we can load this image 
         CodecsImageInfo info = codecs.GetInformation(fileName, false, 1); 
 
         if (info.Format != RasterImageFormat.Unknown) 
         { 
            // Yes, calculate the thumbnail size to fit into RasterImageList.ItemImageSize 
            Rectangle rc = new Rectangle( 
               0, 
               0, 
               imageList.ItemImageSize.Width, 
               imageList.ItemImageSize.Height); 
 
            rc = RasterImageList.GetFixedAspectRatioImageRectangle(info.Width, info.Height, rc); 
 
            // Load the thumbnail 
            image = codecs.Load( 
               fileName, 
               rc.Width, 
               rc.Height, 
               24, 
               RasterSizeFlags.Resample, 
               CodecsLoadByteOrder.BgrOrGray, 
               1, 
               1); 
         } 
         else 
            image = null; 
      } 
      catch 
      { 
         image = null; 
      } 
      return image; 
   } 
} 
 
public void RasterImageList_Image() 
{ 
   MyForm2 form = new MyForm2(); 
   form.ShowDialog(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
}

Requirements

Target Platforms