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Leadtools.Controls Assembly > Leadtools.Controls Namespace > ImageViewer Class : HitTestItem Method |
public virtual ImageViewerItem HitTestItem( LeadPoint point )
'Declaration
Public Overridable Function HitTestItem( _ ByVal point As LeadPoint _ ) As ImageViewerItem
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.
This example will add a few items to the viewer and then perform hit-testing using the mouse showing the specific item part.
Run the demo, click the Example button and notice perform hit-testing.
Start with the ImageViewer example, remove all the code inside the example function (search for the "// TODO: add example code here" comment) and insert the following code:
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.ItemPadding = New Padding(8, 8, 8, 20) _imageViewer.ImageBorderThickness = 1 ' 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 item.Text = String.Format("Item {0}", page - 1) _imageViewer.Items.Add(item) Next page End Using Dim itemPartNames As String() = {"View", "Item", "Content", "Image", "TextArea", "Text", "Floater"} ' Hook to the viewer mouse click event AddHandler _imageViewer.MouseClick, Sub(sender, e) Dim point As LeadPoint = LeadPoint.Create(e.X, e.Y) ' Hit-test the item Dim item As ImageViewerItem = _imageViewer.HitTestItem(point) ' If we have an item, find out the part If Not item Is Nothing Then Dim part As ImageViewerItemPart = _imageViewer.HitTestItemPart(item, point) _label.Text = String.Format("Clicked the {0} part of item at index {1}", itemPartNames(CInt(part)), _imageViewer.Items.IndexOf(item)) Else _label.Text = "Click the view" End If
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.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(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); } item.Text = string.Format("Item {0}", page - 1); _imageViewer.Items.Add(item); } } string[] itemPartNames = { "View", "Item", "Content", "Image", "TextArea", "Text", "Floater" }; // Hook to the viewer mouse click event _imageViewer.MouseClick += (sender, 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); _label.Text = string.Format("Clicked the {0} part of item at index {1}", itemPartNames[(int)part], _imageViewer.Items.IndexOf(item)); } else { _label.Text = "Click the view"; } };