Renders the item image.
public event EventHandler<ImageViewerRenderEventArgs> RenderImage
public:
event EventHandler<Leadtools::Controls::ImageViewerRenderEventArgs^>^ RenderImage
For more information, refer to Image Viewer Rendering.
using Leadtools;
using Leadtools.Controls;
using Leadtools.Codecs;
using Leadtools.Drawing;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Color;
public void ImageViewerPostRender_Example()
{
// 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);
}
}
// Render on the view
_imageViewer.PostRender += (sender, e) =>
{
// Rendering the whole view
var graphics = e.PaintEventArgs.Graphics;
// Blue ellipse at fixed position. This will stay the same and will not scroll or zoom
using (var brush = new SolidBrush(Color.FromArgb(128, Color.Blue)))
graphics.FillEllipse(brush, new Rectangle(0, 0, 100, 100));
// Red ellipse at relative position, this will scroll and zoom with the view
var gstate = graphics.Save();
var transform = _imageViewer.ViewTransform;
using (var matrix = new System.Drawing.Drawing2D.Matrix(
(float)transform.M11, (float)transform.M12, (float)transform.M21, (float)transform.M22,
(float)transform.OffsetX, (float)transform.OffsetY))
graphics.MultiplyTransform(matrix);
graphics.FillEllipse(Brushes.Red, new Rectangle(0, 0, 100, 100));
graphics.Restore(gstate);
};
// Render on each item
_imageViewer.PostRenderItem += (sender, e) =>
{
var item = e.Item;
var graphics = e.PaintEventArgs.Graphics;
var gstate = graphics.Save();
// Get the bounding rectangle for the image
var bounds = LeadRectD.Create(0, 0, item.Image.ImageWidth, item.Image.ImageHeight);
// Add the image transform to the graphics
var transform = _imageViewer.GetItemImageTransform(item);
using (var matrix = new System.Drawing.Drawing2D.Matrix(
(float)transform.M11, (float)transform.M12, (float)transform.M21, (float)transform.M22,
(float)transform.OffsetX, (float)transform.OffsetY))
graphics.MultiplyTransform(matrix);
// Red hilight on top of each item image
using (var brush = new SolidBrush(Color.FromArgb(128, Color.Red)))
graphics.FillRectangle(brush, (float)bounds.X, (float)bounds.Y, (float)bounds.Width, (float)bounds.Height);
graphics.Restore(gstate);
};
}
static class LEAD_VARS
{
public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images";
}
Parameter | Type | Description |
---|---|---|
sender | object | The source of the event. |
e | ImageViewerRenderEventArgs | The event data. |
Help Collections
Raster .NET | C API | C++ Class Library | HTML5 JavaScript
Document .NET | C API | C++ Class Library | HTML5 JavaScript
Medical .NET | C API | C++ Class Library | HTML5 JavaScript
Medical Web Viewer .NET
Multimedia
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Media Foundation .NET | C API | Transforms
Supported Platforms
.NET, Java, Android, and iOS/macOS Assemblies
Imaging, Medical, and Document
C API/C++ Class Libraries
Imaging, Medical, and Document
HTML5 JavaScript Libraries
Imaging, Medical, and Document
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