Develop Reference

How to resize chart more than screen resolution?

I have a C# 4.7 WinForms application with line chart. I want to save chart image with very large resolution e.g 10000x2000. Here is what I have archived:
Form1.Width = 3860; //my screen width resolution - maximum allowed
Form1.Height = 1080; //my screen height resolution - maximum allowed
chart1.Dock = DockStyle.Fill;
chart1.SaveImage(saveFile.FileName, ChartImageFormat.Jpeg);
That code saves jpeg image with 3860x1080 resolution and i can zoom in points I need. But it is not enough and I want to enlarge my form or chart to
get an image like 10000x2000, VS says it cannot be larger than my screen.
I have a lot of data on this chart, so bigger form provides me with more data on a chart. Picture is required for other people to see the maximum info.
How can I do it?

This is quite simple.
All you need to do is create the Chart in code without displaying it on screen.
Now you can size it as needed..:
Chart bigChart = new Chart();
bigChart.ChartAreas.Add("ca");
Series s1 = bigChart.Series.Add("s1");
s1.BorderWidth = 5;
s1.ChartType = SeriesChartType.Line;
// testdata
Random rnd = new Random(8);
for (int i = 0; i < 111; i++)
{
s1.Points.AddXY(rnd.Next(123) + i, rnd.Next(12 * i)) ;
}
bigChart.Size = new Size(10000, 8000);
bigChart.SaveImage(filename, ChartImageFormat.Png);
A few notes:
You may want to add a Legend as well, as the dynamically created Chart has none of the default elements..
If you want to you can use a chart you have, serialize its content to a file (or stream) and then load (deserialize) it into the big chart..
The automatic smartness of MSChart tends to hit some limit when the sizes grow a lot; so brace yourself for tweaking some settings for line width, Fonts etc..
You also may want to load the saved image and set the dpi to a bigger values than the default, which is the screen resolution..
Final remark: Sometimes it is better to save the chart as a vector format; these are also provided in the SaveImage method.
Update: Maybe you want to combine vector and pixel formats as in Jimi's last comments.
You may want to study this post which discusses a few general options.

Using Digital Ink in PowerPoint .NET

I was wondering how PowerPoint slides can be automatically annotated using digital ink in .NET (using c#). Currently, I'm doing the same thing using free-form shapes, which is straightforward but has some issues. When selecting Office.MsoEditingType.msoEditingAuto as an editing type, the free-forms are smooth, but when constructing them and then converting into a shape (when consisting of more than a couple of points) takes a very long time (the following method would take ca 5s!)
PowerPoint.Shape Shape = builder.ConvertToShape();
When using Office.MsoEditingType.msoEditingCorner, the shape is generated much quicker, but the resulting shapes are jagged (surprise!).
I found the following code sample for doing the same using digital ink:
DrawingAttributes drawingAttributes1 = new DrawingAttributes();
drawingAttributes1.Color = Colors.Green;
StylusPoint stylusPoint1 = new StylusPoint(100, 100);
StylusPoint stylusPoint2 = new StylusPoint(100, 200);
StylusPoint stylusPoint3 = new StylusPoint(200, 200);
StylusPoint stylusPoint4 = new StylusPoint(200, 100);
StylusPoint stylusPoint5 = new StylusPoint(100, 100);
StylusPointCollection points = new StylusPointCollection(
new StylusPoint[] { stylusPoint1, stylusPoint2, stylusPoint3,
stylusPoint4, stylusPoint5 });
Stroke newStroke = new Stroke(points, drawingAttributes1);
InkPresenter inkPres = new InkPresenter();
inkPres.Strokes.Add(newStroke);
However, not being a PowerPoint Add-in expert (hardly even a beginner, actually), I don't know how to attach the inkpresenter to the current slide. Ideally, a new inkpresenter would be created & kept per slide (so I don't have to worry about re-drawing on each slide navigation)
I understood it's possible to create an ink canvas using the designer, and then drawing on that, but would that canvas then be attached to the entire presentation or just the current slide? And would it allow users to draw on the canvas (which is not the goal; drawing would be done automatically)?
I spent quite some time looking for relevant code samples, but none of them seemed to do what I am intending. For instance, as mentioned, I'm not planning to allow users to draw on the slide, but automatically annotating the slide.
Thanks,
William

Multiple y-axis background colors for chart

How can I create a background for a chart that looks like this?
It's got different background colors at certain % levels that correspond to the status. All I see in ChartArea is BackColor, BackSecondaryColor, and BackGradientStyle which won't do this. This image was taken from an SSRS report and I am trying to recreate it using C# and the Microsoft charting library. I am pretty sure SSRS uses the same library so it should be possible - I just don't know how.

You can achieve this by using StripLine.
// Create the stripline for 'gold status'
StripLine sline = new StripLine();
sline.IntervalOffset = 0.6;
sline.StripWidth = 0.25;
sline.Text = "Gold Status";
sline.Interval = 0.0; // this ensures it will not repeat like normal strip lines
sline.BackColor = Color.Yellow;
myChart.AxisY.StripLines.Add(sline);
repeat the process for your silver and platinum strip lines.

Exporting a transparent TChart PNG distorts text

I'm using Steema TeeChart v4.1.2010.11303. I want to export a chart to a PNG image with a transparent background.
The resulting image has "distorted" or bold text in the left and bottom axis and in the header. It looks like being rendered with a raster font with a too low resolution. The legend on the right on the other hand looks fine:
The following sample code can be used to reproduce the problem:
TChart tChart = new TChart();
tChart.Aspect.View3D = false;
tChart.Panel.Brush.Gradient.Visible = false;
// Make the background of the chart transparent.
tChart.Panel.Transparent = true;
Steema.TeeChart.Styles.Bar series1 = new Steema.TeeChart.Styles.Bar( tChart.Chart );
series1.FillSampleValues();
tChart.Draw();
tChart.Graphics3D.BufferStyle = Steema.TeeChart.Drawing.BufferStyle.None;
using ( System.IO.Stream stream = new System.IO.MemoryStream() )
{
tChart.Export.Image.PNG.Width = m_PictureBox.Width;
tChart.Export.Image.PNG.Height = m_PictureBox.Height;
tChart.Export.Image.PNG.Save( stream );
// Show the bitmap in a Windows Forms PictureBox.
// Alternatively, it can also be saved in a file, which makes no difference.
PictureBox.Image = new Bitmap( stream );
}
When switching off the transparency with tChart.Panel.Transparent = false;, all text looks fine. However, I need a transparent background.
Is this a bug in TeeChart or am I missing something?

It is a know behavior for us and we haven't found a good solution for this problem, for the moment. If we will find a solution that we consider correct or we will arrive an interesting conclusion about problem of png export, we will inform you immediatly.
Thanks.
Best Regard,
Sandra Pazos

.NET set image display size

I am using some custom controls one of which is a tooltip controller that can display images, so I am using th ebelow code to instantiate it:
Image newImage = Image.FromFile(imagePath);
e.ToolTipImage = newImage;
obviously could inline it but just testing at the moment. The trouble is the image is sometimes the wrong size, is there a way to set the display size. The only way I can currently see is editing the image using GDI+ or something like that. Seems like a lot of extra processing when I am only wanting to adjust display size not affect the actual image.

Once you have an image object loaded from its source, the Height and Width (and Size, and all ancillary properties) are read-only. Therefore, you are stuck with GDI+ methods for resizing it in RAM and then displaying it accordingly.
There are a lot of approaches you can take, but if you were to encapsulate that out to a library which you could reuse should this problem occur again, you'll be set to go. This isn't exactly optimized (IE, may have some bugs), but should give you an idea of how to approach it:
Image newImage = Image.FromFile(myFilePath);
Size outputSize = new Size(200, 200);
Bitmap backgroundBitmap = new Bitmap(outputSize.Width, outputSize.Height);
using (Bitmap tempBitmap = new Bitmap(newImage))
{
using (Graphics g = Graphics.FromImage(backgroundBitmap))
{
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
// Get the set of points that determine our rectangle for resizing.
Point[] corners = {
new Point(0, 0),
new Point(backgroundBitmap.Width, 0),
new Point(0, backgroundBitmap.Height)
};
g.DrawImage(tempBitmap, corners);
}
}
this.BackgroundImage = backgroundBitmap;
I did test this, and it worked. (It created a 200x200 resized version of one of my desktop wallpapers, then set that as the background image of the main form in a scratch WinForms project. You'll need using statements for System.Drawing and System.Drawing.Drawing2D.

In Winforms, if you contain the image inside a PictureBox control, the PictureBox control can be set to zoom to a particular height/width, and the image should conform.
At least that's what happened in my Head First C# book when I did the exercise.