Greetings,
I've tested the image export functionality of RadChartView, however, the output quality isn't quite high, and therefore, it isn't appropriate for printing stuff (I tested JPEG format).
I also searched for PDF output of RadChartView, most implemented methods are all about putting an exported image of RadChartView into a PDF document.
First Question : Is it possible to export a high-quality image of RadChartView? and is it possible to change the background color of the exported image? (as default it exports the image with white background; JPEG)
Second Question : What's the best way to export a RadChartview into a PDF document?
Thanks in advance.
1 Answer, 1 is accepted
0
Accepted
Hello, George,
There is not straightforward way to change the quality of the exported image. You can find below the default logic for exporting RadChartView as an image:
There is not straightforward way to change the quality of the exported image. You can find below the default logic for exporting RadChartView as an image:
public void ExportToImage(Stream stream, Size size, ImageFormat imageFormat)
{
if (!this.IsLoaded)
{
this.LoadElementTree();
}
Bitmap bmp = new Bitmap(size.Width, size.Height);
Graphics graphics = null;
Graphics fromBitmapGraphics = null;
Metafile metafile = null;
bool isMetaFile = imageFormat == ImageFormat.Emf || imageFormat == ImageFormat.Wmf;
if (isMetaFile)
{
fromBitmapGraphics = Graphics.FromImage(bmp);
metafile = new Metafile(stream, fromBitmapGraphics.GetHdc());
graphics = Graphics.FromImage(metafile);
}
else
{
graphics = Graphics.FromImage(bmp);
}
graphics.Clear(Color.White);
StringFormat titleStringFormat = this.ChartElement.TitleElement.TextParams.CreateStringFormat();
// Set no trimming - TFS issue id #436542
titleStringFormat.Trimming = StringTrimming.None;
SizeF titleSize = graphics.MeasureString(this.Title, this.ChartElement.TitleElement.Font, this.Width, titleStringFormat);
if (this.ChartElement.TitleElement.TextOrientation == Orientation.Vertical)
{
float swap = titleSize.Height;
titleSize.Height = titleSize.Width;
titleSize.Width = swap;
}
RadRect titleRect = new RadRect(0, 0, titleSize.Width, titleSize.Height);
RadRect legendRect = new RadRect(0, 0, size.Width, size.Height);
RadRect chartRect = legendRect;
titleRect.X += this.chartElement.TitleElement.PositionOffset.Width;
titleRect.Y += this.chartElement.TitleElement.PositionOffset.Height;
switch (this.chartElement.TitlePosition)
{
case TitlePosition.Top:
case TitlePosition.Bottom:
titleRect.Width = size.Width;
break;
case TitlePosition.Right:
case TitlePosition.Left:
titleRect.Height = size.Height;
break;
}
chartRect.X += this.View.Margin.Left;
chartRect.Y += this.View.Margin.Top;
chartRect.Width -= this.View.Margin.Horizontal;
chartRect.Height -= this.View.Margin.Vertical;
if (this.ShowTitle)
{
switch (this.ChartElement.TitlePosition)
{
case TitlePosition.Top:
legendRect.Y += titleRect.Height;
chartRect.Y += titleRect.Height;
legendRect.Height -= titleRect.Height;
chartRect.Height -= titleRect.Height;
break;
case TitlePosition.Right:
titleRect.X = size.Width - this.ChartElement.TitleElement.Size.Width;
titleRect.Height = size.Height;
legendRect.Width -= titleRect.Width;
chartRect.Width -= titleRect.Width;
break;
case TitlePosition.Bottom:
titleRect.Y = size.Height - this.ChartElement.TitleElement.Size.Height;
titleRect.Width = size.Width;
legendRect.Height -= titleRect.Height;
chartRect.Height -= titleRect.Height;
break;
case TitlePosition.Left:
titleRect.Height = size.Height;
legendRect.X += titleRect.Width;
chartRect.X += titleRect.Width;
legendRect.Width -= titleRect.Width;
chartRect.Width -= titleRect.Width;
break;
}
}
if (this.ShowLegend)
{
switch (this.ChartElement.LegendPosition)
{
case LegendPosition.Right:
if (this.ChartElement.TitlePosition == TitlePosition.Right)
{
legendRect.X = titleRect.X - this.ChartElement.LegendElement.Size.Width;
}
else
{
legendRect.X = size.Width - this.ChartElement.LegendElement.Size.Width;
}
legendRect.Width = this.ChartElement.LegendElement.Size.Width;
chartRect.Width -= legendRect.Width;
break;
case LegendPosition.Bottom:
if (this.ChartElement.TitlePosition == TitlePosition.Bottom)
{
legendRect.Y = titleRect.Y - this.ChartElement.LegendElement.Size.Height;
}
else
{
legendRect.Y = size.Height - this.ChartElement.LegendElement.Size.Height;
}
legendRect.Height = this.ChartElement.LegendElement.Size.Height;
chartRect.Height -= legendRect.Height;
break;
case LegendPosition.Left:
legendRect.Width = this.ChartElement.LegendElement.Size.Width;
chartRect.X += legendRect.Width;
chartRect.Width -= legendRect.Width;
break;
case LegendPosition.Top:
legendRect.Height = this.ChartElement.LegendElement.Size.Height;
chartRect.Y += legendRect.Height;
chartRect.Height -= legendRect.Height;
break;
case LegendPosition.Float:
legendRect.Width = this.ChartElement.LegendElement.Size.Width;
legendRect.Height = this.ChartElement.LegendElement.Size.Height;
double xRatio = size.Width / this.Size.Width;
double yRatio = size.Height / this.Size.Height;
legendRect.X = (this.ChartElement.LegendOffset.X * xRatio) + ((this.ChartElement.TitlePosition == TitlePosition.Left) ? titleRect.Right : 0d);
legendRect.Y = (this.ChartElement.LegendOffset.Y * yRatio) + ((this.ChartElement.TitlePosition == TitlePosition.Top) ? titleRect.Bottom : 0f);
break;
}
}
this.View.Layout(chartRect);
this.Area.Renderer.Draw(graphics);
if (this.ShowLegend)
{
float xTransform = (float)legendRect.X - this.ChartElement.LegendElement.ControlBoundingRectangle.X + ((float)legendRect.Width - this.ChartElement.LegendElement.ControlBoundingRectangle.Width) / 2f;
float yTransform = (float)legendRect.Y - this.ChartElement.LegendElement.ControlBoundingRectangle.Y + ((float)legendRect.Height - this.ChartElement.LegendElement.ControlBoundingRectangle.Height) / 2f;
graphics.TranslateTransform(xTransform, yTransform);
this.ChartElement.LegendElement.Paint(new RadGdiGraphics(graphics), this.ChartElement.LegendElement.ControlBoundingRectangle, 0f, new SizeF(1f, 1f), true);
graphics.ResetTransform();
}
RadGdiGraphics radGraphics = new RadGdiGraphics(graphics);
if (this.ShowTitle)
{
radGraphics.DrawString(
this.Title,
this.GetTitleDrawRectangle(ChartRenderer.ToRectangleF(titleRect), titleSize, this.ChartElement.TitleElement.TextAlignment),
this.ChartElement.TitleElement.Font,
this.ChartElement.TitleElement.ForeColor,
titleStringFormat,
this.ChartElement.TitleElement.TextOrientation,
this.ChartElement.TitleElement.FlipText);
}
if (isMetaFile)
{
metafile.Dispose();//this will save the metafile to stream
if (fromBitmapGraphics != null)
{
fromBitmapGraphics.Dispose();
}
}
else
{
bmp.Save(stream, imageFormat);
}
this.View.Layout();
}The CaresianRenderer uses the default DrawPart for each series for drawing:
public override void Draw(object context)
{
if (renderPass < 2)
{
if (this.Area.View.Owner.Control.Site == null)
{
for (int i = 0; i < this.Area.Series.Count; i++)
{
if (this.Area.Series[i].IsVisible && !this.Area.Series[i].Model.IsArrangeValid)
{
this.Area.View.Layout(false);
renderPass++;
break;
}
}
}
}
base.Draw(context);
Initialize();
for (int i = 0; i < this.drawParts.Count; i++)
{
this.drawParts[i].Draw();
}
this.renderPass = 0;
}It is possible to export the chart to an image as it looks by using the well known Control.DrawToBitmap method:
https://docs.microsoft.com/en-us/dotnet/api/system.windows.forms.control.drawtobitmap?view=net-5.0
If you need to export the chart data to a document, e.g. pdf, you can use a RadDocument and insert the exported image into it. Afterwards, you can use the RadRichTextEditor 's export functionality.
I believe that it would be useful for achieving your goal.
Regards,
Dess | Tech Support Engineer, Principal
Progress Telerik
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