HitTestItemPart Method

Summary

Specific part of the item under a physical (in viewer pixel) coordinates.

Syntax

C++/CLI

public virtual ImageViewerItemPart HitTestItemPart( 
   ImageViewerItem item, 
   LeadPoint point 
)

public:  
   virtual ImageViewerItemPart^ HitTestItemPart( 
      ImageViewerItem^ item, 
      LeadPoint^ point 
   )

Parameters

item

The reference item. This value cannot be null.

point

The point in physical (in viewer pixel) coordinates.

Return Value

The specific item part under the specified point, or ImageViewerItemPart.View if the point is not over the item.

Remarks

HitTestItem method will return the item if any part of it is under the specified point. To further fine-tune the hit testing operation and obtain the specific item part, call HitTestItemPart passing the item obtained from HitTestItem and the desired part.

For more information refer to Image Viewer Layouts, Image Viewer Appearance, Image Viewer Items, Image Viewer Transformation, and Image Viewer Bounds and Transform.

Example

using Leadtools; 
using Leadtools.Controls; 
using Leadtools.Codecs; 
using Leadtools.Drawing; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
 
 
public ImageViewerForm _form = new ImageViewerForm(); 
public ImageViewer _imageViewer; 
 
private string[] itemPartNames = 
{ 
   "View", 
   "Item", 
   "Content", 
   "Image", 
   "TextArea", 
   "Text", 
   "Floater" 
}; 
 
public void ImageViewerHitTestItemExample() 
{ 
   // Get the ImageViewer control from the form 
   _imageViewer = _form.ImageViewer; 
   // 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.ItemPadding = new Padding(8, 8, 8, 20); 
   _imageViewer.ImageBorderThickness = 1; 
 
   // 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(LEAD_VARS.ImagesDir, 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); 
         } 
 
         item.Text = string.Format("Item {0}", page - 1); 
         _imageViewer.Items.Add(item); 
      } 
   } 
 
   // Hook to the viewer mouse click event 
   _imageViewer.MouseClick += _imageViewer_MouseClick; 
} 
 
private void _imageViewer_MouseClick(object sender, MouseEventArgs e) 
{ 
   var point = LeadPoint.Create(e.X, e.Y); 
   // Hit-test the item 
   var item = _imageViewer.HitTestItem(point); 
   // If we have an item, find out the part 
   if (item != null) 
   { 
      var part = _imageViewer.HitTestItemPart(item, point); 
      Debug.WriteLine(string.Format("Clicked the {0} part of item at index {1}", 
         itemPartNames[(int)part], 
         _imageViewer.Items.IndexOf(item))); 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}

Requirements

Target Platforms

Reference

ImageViewer Class

ImageViewer Members

Leadtools.Controls Namespace

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Help Version 23.0.2024.2.29