Jurgen .NET

A lot of applications need to display formatted text in a table. Out of the box the DataGridView only supports a TextBox column type for which the formatting options are quite limited. As the cells within a DataGridView are no standard user controls it is no trivial task to implement. I implemented a RichTextBox column type based on the following Microsoft knowledge base article:

     Print the Content of a RichTextBox

This article shows how to render the RichTextBox content on a printer device context using the EM_FORMATRANGE message. Instead of the printer I let this code render the content on a device context for a Bitmap:

    Image LimgImage = ...
    Graphics LobjGraphics = Graphics.FromImage(LimgImage);
    IntPtr LobjHdc = LobjGraphics.GetHdc();

This image is then rendered in the Paint event of the cell.

In my application it was furthermore necessary to edit the content in the cells. For this I used the default RichTextBox. It required quite some time to get the sizing right so the image rendered in display mode exactly fitted the content of the RichTextBox used to enter the content, but at the end all the magic numbers involved were :-)