Exporting Chart as Image

[brownhead]

My program needs to be able to export the reports it creates into PDF files. I can make the PDF file just fine, but in order to add the Chart I need to save the Chart as an image, preferably PNG.

Now comes the trouble spot, the chart needs to be resized inside the export function in order for it to fit smoothly on the page. How can I do this without displaying the chart to the user?

I'm having difficulty explaining this so perhaps an example will help

public void ToPFD(string FileName, Chart zChart){

// PDF functions up above// Set the width and height of the chartzChart.Width = zChart.Height = Math.Min(pdfPage.Width - 30, pdfPage.Height - tblEnd - 60);

/* I have tried calling Refresh(), all the Invalidate*() functions, * and anything else that seemed likely to work here. None of them * did. I believe because there Asynchronous.. I was trying to * put to sleep this thread and then interrupt it when the refresh * was done but I couldn't figure out what event was called when * the refresh was finished. */

// Export the chartzChart.Export(tmpFile);

}

Thanks for taking a look. Hope to resolve this problem soon as I see no work around.

[brownhead]

Perhaps I should clarify this. My question is how do I make the chart do a complete redraw (including adjusting to its new dimensions) synchronously. A function call that doesn't return until the operation is finished is more or less what I'm looking for.

I desperatley need a solution for this and I haven't been able to find one.

[JuanC]

Unfortunately WPF does most of its job in a "render thread" so I am not sure if you can force a complete redraw asynchronously, even if you did do you want the chart to grow/shrink when generating the PDF?

Have you considered creating a separate chart only used for the export? We added some special code to support this scenario of exporting a chart that has never been visible.

Regards,

JuanC

[brownhead]

I saw a post of yours that mentioned you had figured that out. I sent you a message about it yesterday. How would I go about doing that? Because that would be an excellant workaround.

[JuanC]

I do not think we got your email.

You will have to create a chart object in code and customize it in a similar way as the one being displayed on the screen, including binding it to the same data source.

Regards,

JuanC

[brownhead]

 I had actually send a Private Message directly to you using the forum.

 And creating a chart object then exporting it is not working for me. This is the code I'm using. (zChart is a reference to the original chart)

  ChartFX.WPF.Chart newChart = new ChartFX.WPF.Chart();
  newChart.Width = newChart.Width = Math.Min(page.Width - 30, page.Height - tblEnd - 60);
  newChart.Style = ChartFX.WPF.Motifs.Basic.Style;
  newChart.ItemsSource = zChart.ItemsSource;
 
  // Export the chart to a png file
  newChart.Export(ChartFX.WPF.FileFormat.Png, tmpPath);

[JuanC]

I never got your private message. Can you expand on what is "not working" when using that code? Do you get an empty image? Can you post the image you get? Are you executing this code on the UI thread or are you creating a background thread?

Regards,

JuanC

[brownhead]

By not working I mean a blank chart is exported. I have attached the exported image.

The thread that the function is executing on is the main UI thread.

 Hope to hear back from you soon.

[brownhead]

 I've been able to ignore this problem and continue working, but its still a problem that needs to be fixed before release. Is there a known solution as of yet?

[JuanC]

We have been unable to reproduce this problem, in our tests using the sample code you posted results in a valid png, this is the code we tested.

ChartFX.WPF.Chart newChart = new ChartFX.WPF.Chart();newChart.Width = 500;newChart.Height = 300;newChart.Style = ChartFX.WPF.Motifs.Basic.Style;newChart.ItemsSource = zChart.ItemsSource;

// Export the chart to a png filenewChart.Export(ChartFX.WPF.FileFormat.Png, "C:\\Temp\\Test.png");

Are you using any special settings in the XAML or Code for zChart? Have you tried to duplicate this issue in a sample app with a XAML Window with a simple chart (you might use an XmlDataProvider with dummy chart so that you can send us a complete sample).

To help us try to reproduce the problem please post the following information:

OS including Service Pack.NET Version including Service PackFile Version for ChartFX.WPF.dllVideo Card Manufacturer and Driver Version

Regards,

JuanC

ChartFXWPFTest12.zip

[brownhead]

My system spec:

OS Name: Microsoft

[JuanC]

Can you double check the file version for ChartFX.WPF.dll? It should be 8.0.NNNN.NNNN.

2.0.50727 sounds like the version of the .NET framework 2.0

JuanC

[brownhead]

Ah, my mistake.

Chart FX Version: 8.0.3155.18127

[JuanC]

I would recommend you download and install our RC1 bits.

JuanC

[brownhead]

It works now, thank you very much for all of your help.