Color to use to fill the background area.
public Color BackgroundColor { get; set; }
public:
property System::Drawing::Color^ BackgroundColor
{
System::Drawing::Color^ get()
void set(System::Drawing::Color^ value)
}
The color to use to fill the background area. Default value is "Transparent".
The default value of "Transparent" will instruct RenderRedirect to not erase the background of the target control during rendering. Otherwise, set this value to the desired color. 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 ImageViewerForm _form = new ImageViewerForm();
public ImageViewer _imageViewer;
public PictureBox redirectRenderControl;
public void ImageViewerRedirectRenderExample()
{
// Get the ImageViewer control from the form
_imageViewer = _form.ImageViewer;
// Load an image
using (var codecs = new RasterCodecs())
_imageViewer.Image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "cannon.jpg"));
// PanZoom Interactive Mode
_imageViewer.DefaultInteractiveMode = new ImageViewerPanZoomInteractiveMode();
// Separate Form with PictureBox control
Form redirectRenderForm = new Form();
redirectRenderControl = new PictureBox();
redirectRenderControl.Width = 400;
redirectRenderControl.Dock = DockStyle.Fill;
redirectRenderForm.Controls.Add(redirectRenderControl);
redirectRenderForm.Show();
// Invalidate on double-click
bool renderView = false;
redirectRenderControl.DoubleClick += (sender, e) =>
{
renderView = !renderView;
redirectRenderControl.Invalidate();
};
redirectRenderControl.Paint += (sender, e) =>
{
if (_imageViewer.Image == null)
return;
// Get PictureBox Graphics object
Graphics graphics = e.Graphics;
// Destination rectangle in PictureBox
int margin = 20;
LeadRect destRect = LeadRect.Create(margin, margin, redirectRenderControl.ClientSize.Width - margin * 2, redirectRenderControl.ClientSize.Height - margin * 2);
LeadRect clipRect = destRect;
// Source rectangle
Debug.WriteLine(_imageViewer.ViewSize);
// RenderRedirect Options
ImageViewerRenderRedirectOptions options = new ImageViewerRenderRedirectOptions();
options.BackgroundColor = Color.Transparent;
// Try to get item from the viewer
ImageViewerItem item = null;
if (!renderView)
item = _imageViewer.Items[0];
LeadRectD sourceRect = LeadRectD.Empty;
if (item == null)
sourceRect = _imageViewer.GetViewBounds(true, false);
else
{
sourceRect = _imageViewer.GetItemViewBounds(item, ImageViewerItemPart.Image, false);
options.RenderBackgrounds = false;
options.RenderBorders = false;
options.RenderItemStates = false;
options.RenderShadows = false;
options.RenderText = false;
}
// Transformation Matrix (represents rotation, zooming...etc)
Debug.WriteLine(_imageViewer.ViewTransform);
options.CreateTransform(_imageViewer, destRect, sourceRect, ControlSizeMode.FitAlways, ControlAlignment.Center, ControlAlignment.Center);
clipRect = options.Transform.TransformRect(sourceRect).ToLeadRect();
// Redirect rendering to the PictureBox Graphics object (Outlined with a black rectangle)
_imageViewer.RenderRedirect(graphics, options, clipRect);
graphics.DrawRectangle(Pens.Black, destRect.X, destRect.Y, destRect.Width + 1, destRect.Height + 1);
// Calculate visible view
LeadRectD rect;
if (item == null)
rect = _imageViewer.GetViewBounds(true, true);
else
rect = _imageViewer.GetItemViewBounds(item, ImageViewerItemPart.Image, true);
LeadPointD[] points =
{
LeadPointD.Create(rect.Left, rect.Top),
LeadPointD.Create(rect.Right, rect.Bottom)
};
options.Transform.TransformPoints(points);
double xmin = points[0].X;
double ymin = points[0].Y;
double xmax = xmin;
double ymax = ymin;
for (int i = 1; i < points.Length; i++)
{
if (points[i].X < xmin) xmin = points[i].X;
if (points[i].X > xmax) xmax = points[i].X;
if (points[i].Y < ymin) ymin = points[i].Y;
if (points[i].Y > ymax) ymax = points[i].Y;
}
// Draw yellow rectangle showing visible part of the view
LeadRectD bounds = LeadRectD.FromLTRB(xmin, ymin, xmax, ymax);
RectangleF rc = new RectangleF((float)bounds.X, (float)bounds.Y, (float)bounds.Width, (float)bounds.Height);
graphics.DrawRectangle(Pens.Yellow, rc.X, rc.Y, rc.Width - 1, rc.Height - 1);
};
_imageViewer.RedirectRender += (sender, e) =>
{
redirectRenderControl.Invalidate();
};
}
static class LEAD_VARS
{
public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images";
}
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