I'm trying to take a screenshot of a datagrid which has to many rows to be displayed. So there is a scrollviewer.
So when I just put the datagrid into the Render Method of RenderTargetBitmap I obviously just get the viewable part of the datagrid.
I read that one can take a screenshot of a content when actually rendering the ItemsPresenter of the ScrollViewer of that control, as the ItemsPresenter would have the "real" Width and Height of the content.
Unfortunatly my ScrollViewer doesnt have any different Height, ActualHeight or RenderSize.Height than the dataGrid.
So I always just get the visible part of the Content.
Anyone know how to do this the right way, that it actually takes the whole content ?
Code:
var scroll = GetTemplateChildByName(dataGridInOut);
if (scroll != null)
{
var item = scroll.Content as ItemsPresenter;
var width = item.RenderSize.Width;
var height = item.RenderSize.Height;
var rtb = new RenderTargetBitmap((int) Math.Round(width), (int)Math.Round(height), 96, 96,
PixelFormats.Pbgra32);
var drawingVisual = new DrawingVisual();
var visualBrush = new VisualBrush(item);
using (var context = drawingVisual.RenderOpen())
{
context.DrawRectangle(visualBrush, null, new Rect(new Point(0,0), new Size(width, height)));
}
rtb.Render(drawingVisual);
Clipboard.SetImage(rtb);
}
Leaf is right. You could instantiate another DataGrid bound to the same source programmatically, put it into a container which gives it infinite space, wait for it to render and then take a screenshot of this. No need to actually show it in the UI.
Related
I'm using a DataGrid to represent some data in a WPF application. In a feature where I'm saving a particular WPF Window which has the DataGrid into a PDF using PDFSharp, I'm facing an issue that the DataGrid GridLines are not visible when the saved PDF is viewed in smaller viewing percentages.
(Refer attached images, only when the PDF view is set at 139%, the GridLines are visible. However, in smaller viewing %, some grid lines get omitted.)
Here's the PDF Saving Code:-
MemoryStream lMemoryStream = new MemoryStream();
Package package = Package.Open(lMemoryStream, FileMode.Create);
var doc = new System.Windows.Xps.Packaging.XpsDocument(package);
XpsDocumentWriter writer = System.Windows.Xps.Packaging.XpsDocument.CreateXpsDocumentWriter(doc);
VisualBrush sourceBrush = new VisualBrush(this);
DrawingVisual drawingVisual = new DrawingVisual();
using (var drawingContext = drawingVisual.RenderOpen())
{
drawingContext.DrawRectangle(sourceBrush, null, new Rect(new Point(0, 0), new Point(this.ActualWidth, this.ActualHeight)));
}
writer.Write(drawingVisual);
doc.Close();
package.Close();
var pdfXpsDoc = PdfSharp.Xps.XpsModel.XpsDocument.Open(lMemoryStream);
XpsConverter.Convert(pdfXpsDoc, sFileName, 0);
I believe it has to do with the quality with which the visual is drawn. Then I tried this snippet where I'm using DrawImage to make the visual at a higher resolution. Here's the snippet:-
MemoryStream lMemoryStream = new MemoryStream();
Package package = Package.Open(lMemoryStream, FileMode.Create);
var doc = new System.Windows.Xps.Packaging.XpsDocument(package);
XpsDocumentWriter writer = System.Windows.Xps.Packaging.XpsDocument.CreateXpsDocumentWriter(doc);
double dpiScale = 600.0 / 96.0;
var renderBitmap = new RenderTargetBitmap(Convert.ToInt32(this.Width * dpiScale),
Convert.ToInt32(this.Height * dpiScale),
600.0,
600.0,
PixelFormats.Pbgra32);
renderBitmap.Render(this);
var visual = new DrawingVisual();
using (var dc = visual.RenderOpen())
{
dc.DrawImage(renderBitmap, new Rect(0, 0, this.Width, this.Height));
}
writer.Write(visual);
doc.Close();
package.Close();
var pdfXpsDoc = PdfSharp.Xps.XpsModel.XpsDocument.Open(lMemoryStream);
XpsConverter.Convert(pdfXpsDoc, _pdfFileName, 0);
This snippet is working as in the grid lines are visible even in smaller viewing percentages but it makes my application stuck at the PDF save operation and also it throws System.OutofMemoryException with message "Insufficient memory to continue the execution of the program." However, the application doesn't crash.
To check the behavior of PDF viewer, I generated a table with multiple rows and columns in MS Word and saved it as a PDF. In that case, the table grid lines are clearly visible even at small viewing percentages.
Can anyone help me with this?
I assume the first code snippet creates a table in vector format (you do not supply a PDF that allows to verify this).
The second code snippet attempts to create a bitmap image (raster format).
Either way: with both vector and raster images it depends on the PDF viewer whether thin lines are visible. Adobe Reader has many options (like "Enhance thin lines", "Smooth line art", "Smooth images") that will have an effect on the actual display - to be set on the client computer, nothing to be set in the PDF.
I assume your test with MS Word also created a table in vector format, but maybe with thicker lines. So this test proofs nothing.
I had the same problem with disappearing grid lines when zooming out a PDF created with WPF.
The problem was that the TextBox objects in the Grid cells had a default background color (white) and a border color (black), and both were painted in the same place when zooming out. The solution was to not have a background at all, by setting the background to Transparent.
TextBox tx = new TextBox();
tx.Text = "X";
tx.SetValue(Grid.RowProperty, row);
tx.SetValue(Grid.ColumnProperty, col);
tx.BorderThickness = new Thickness(0.3, 0.3, 0, 0);
tx.BorderBrush = System.Windows.Media.Brushes.Black;
tx.Background = Brushes.Transparent;
grid.Children.Add(tx);
But what if you want to have some background in the grid cell? Then the solution is to add a separate Border object to the same Grid cell, and use Zindex to make sure that the Border object is painted in front of the other content.
TextBox tx = new TextBox();
tx.Text = "X";
tx.SetValue(Grid.RowProperty, row);
tx.SetValue(Grid.ColumnProperty, col);
tx.BorderThickness = new Thickness(0);
tx.Background = Brushes.LightPink;
grid.Children.Add(tx);
Border ct = new Border();
ct.SetValue(Grid.RowProperty, row);
ct.SetValue(Grid.ColumnProperty, col);
ct.BorderThickness = new Thickness(0.3, 0.3, 0, 0);
ct.BorderBrush = System.Windows.Media.Brushes.Black;
ct.Background = Brushes.Transparent;
ct.HorizontalAlignment = HorizontalAlignment.Stretch;
ct.VerticalAlignment = VerticalAlignment.Stretch;
Grid.SetZIndex(ct, 100);
grid.Children.Add(ct);
Also, UseLayoutRounding must be set to false (false is default). Otherwise lines with Thickness 0.5 or lower will disappear completely.
I would like to export a grid (whit all his children) to a PNG.
The problem is that some of these children are outside of the grid.
Here is my code:
VisualBrush sourceBrush = new VisualBrush(MyGrid);
DrawingVisual drawingVisual = new DrawingVisual();
using (DrawingContext drawingContext = drawingVisual.RenderOpen())
{
drawingContext.DrawRectangle(sourceBrush, null, new Rect(new Point(0, 0), new Point(Math.Floor(exportWidth), Math.Floor(exportHeight))));
drawingContext.Close();
}
RenderTargetBitmap renderTarget = new RenderTargetBitmap((int)Math.Floor(exportWidth), (int)Math.Floor(exportHeight), 96, 96, PixelFormats.Default);
renderTarget.Render(drawingVisual);
The resulting image is blurred if at least one of the children is outside the grid.
The exportHeight and exportWidth values are calculated upstream, relative to the position of the grid's children.
If all children are inside the grid, the picture is clear.
I think this is because of the VisualBrush original size that cannot be changed.
Do you know a way to fix it ?
EDIT :
I do not call renderTarget.Render(MyGrid); because it does not take in charge children who are outside the grid (Children whose top or left value is negative).
Have you tried?
MyGrid.ClipToBounds = true;
I need a Viewport3D for the sole purpose of doing geometric calculations using Petzold.Media3D.ViewportInfo. I would prefer not to have to place it in a Window or otherwise render it.
I'm attempting to accomplish this by instantiating a Viewport3D and setting a few properties using the following C# method:
private Viewport3D CreateViewport(MainSettings settings)
{
var cameraPosition = new Point3D(0, 0, settings.CameraHeight);
var cameraLookDirection = new Vector3D(0, 0, -1);
var cameraUpDirection = new Vector3D(0, 1, 0);
var camera = new PerspectiveCamera
{
Position = cameraPosition,
LookDirection = cameraLookDirection,
UpDirection = cameraUpDirection
};
var viewport = new Viewport3D
{
Camera = camera,
Width = settings.ViewportWidth,
Height = settings.ViewportHeight
};
return viewport;
}
Later, I'm attempting to use this viewport to convert the mouse location to a 3D location using this method:
public Point3D? Point2dToPoint3d(Point point)
{
var range = new LineRange();
var isValid = ViewportInfo.Point2DtoPoint3D(_viewport, point, out range);
if (isValid)
return range.PointFromZ(0);
else
return null;
}
Unfortunately, it's not working. I think the reason is that the ActualWidth and ActualHeight of the viewport are both zero (and these are read-only properties, so I can't set them manually). (Note: I have tested the exact same method with an actual rendered Viewport3D, and it worked fine, so I know the issue is not with my converter method.)
Any idea how I can get WPF to assign the ActualWidth and ActualHeight of a control based on the Width and Height settings?
I tried setting the HorizontalAlignment and VerticalAlignment to Left and Top, respectively, and I also messed with the MinWidth and MinHeight, but none of these properties had any effect on the ActualWidth or ActualHeight.
From MSDN topic for the ActualWidth property:
This property is a calculated value based on other width inputs, and the layout system. The value is set by the layout system itself, based on an actual rendering pass, and may therefore lag slightly behind the set value of properties such as Width that are the basis of the input change.
So, this sounds like a rendering pass is necessary for the property to be set. However, you could try to call Measure(Size) and then Arrange(Rect) to simulate the layout process. Maybe this is already sufficient.
Im trying to create some chart images without ever displaying those charts on the screen. I'v been at this for quite a while and tried a lot of different things but nothing seems to work. The code works perfectly if I display the chart in a window first, but if I don't display it in a window, the bitmap is just white with a black border (no idea why).
I have tried adding the chart to a border before rendering and giving the border a green borderBrush. In the bitmap, I see the green borderBrush then the black border and white background but no chart. The Chart is not contained in a black boarder so I don't know where that is coming from.
I have tried adding the chart to a window without calling window.Show() and again I just get the black boarder and white background. However if I call window.Show() the bitmap contains the chart.
I have tried using a drawingVisual as explained here, same result.
Here is the code (not including adding the element to a border or window):
private static BitmapSource CreateElementScreenshot(FrameworkElement element, int dpi)
{
if (!element.IsMeasureValid)
{
Size size = new Size(element.Width, element.Height);
element.Measure(size);
element.Arrange(new Rect(size));
}
element.UpdateLayout();
var scale = dpi/96.0;
var renderTargetBitmap = new RenderTargetBitmap
(
(int)(scale * element.RenderSize.Width),(int)(scale * element.RenderSize.Height),dpi,dpi,PixelFormats.Default
);
// this is waiting for dispatcher to perform measure, arrange and render passes
element.Dispatcher.Invoke(((Action)(() => renderTargetBitmap.Render(element))), DispatcherPriority.Render);
return renderTargetBitmap;
}
Note: The chart is a ContentControl.
Is there anyway I can get the chart to render without displaying it in a window first?
Calling element.ApplyTemplate() did the trick.
If someone has similar problems with rendering RenderTargetBitmap (getting white / empty image) items that are in StackPanel you can temporary move them to Grid, then render and put it back in StackPanel
Grid grid = new System.Windows.Controls.Grid() { Background = Brushes.White, Width = iWidth, Height = iHeight };
Panel panel = plot.Parent as Panel;
if (panel != null)
{
panel.Children.Remove(plot);
grid.Children.Add(plot);
grid.Measure(new Size(iWidth, iHeight));
grid.Arrange(new Rect(new Size(iWidth, iHeight)));
}
plot.Measure(new Size(iWidth, iHeight));
plot.Arrange(new Rect(new Size(iWidth, iHeight)));
plot.ApplyTemplate();
plot.UpdateLayout();
grid.ApplyTemplate();
grid.UpdateLayout();
RenderTargetBitmap renderTargetBitmap = new RenderTargetBitmap(
iWidth,
iHeight,
96, 96, PixelFormats.Pbgra32);
renderTargetBitmap.Render(grid);
PngBitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(renderTargetBitmap));
MemoryStream memoryStream = new MemoryStream();
encoder.Save(memoryStream);
bitmap = new System.Drawing.Bitmap(memoryStream);
if (panel != null)
{
grid.Children.Remove(plot);
panel.Children.Add(plot);
}
plot.Measure(new Size(iWidthBefore, iHeightBefore));
plot.Arrange(new Rect(new Size(iWidthBefore, iHeightBefore)));
plot.UpdateLayout();
For me, calling element.Arrange() was the missing piece.
I have a scrollviewer with dynamic content. On an event, a new content is made visible and the scrollbar appears. How do i make it auto scroll to have that content in view?
Thanks,
Shawn Mclean
Use ScrollToVerticalOffset() to do this, passing in the coordinates of the new content.
var newContent = GetNewContent();
var generalTransform = newContent.TransformToVisual(
Application.Current.RootVisual as UIElement);
Point offset = generalTransform.Transform(new Point(0, 0));
double controlTop = offset.Y;
double controlLeft = offset.X;
scrollViewer.ScrollToVerticalOffSet(controlTop);
scrollViewer.ScrollToHorizontalOffSet(controlLeft);
Are you sure Scrollviewer is the control you need here?
Sounds to me like you ought to be using ListBox (which you can heavily style if necessary). It has a ScrollIntoView(item) method which would acheive your goal.