The rich text support of the .NET DataGridView or other commercial components are very basic and in most cases limited to the features of the Microsoft RichTextBox.

To enable users to display more advanced rich content in a DataGridViewCell, you can render the text of TXTextControl.TextControl to the Graphics object of a specific cell.

There are also possibilities to insert the control itself to the cell when it is activated. You can build your own DataGridViewColumn that adds another control to the cell. This project shows how to achieve this:

RichTextBox cell in a DataGridView

Anyway, this sample code shows only how to render the content of TX Text Control to the cell. I am using the CellPainting event of the DataGridView to change the painting. We are just drawing the background of the cell. The e.Handled = true; statement avoids further painting of the cell.

The DrawToBitmap method of TX Text Control is used to create an image of the content which is rendered using the GDI+ DrawImage method. It is a very easy, but effective way to provide rich text content in a data grid.

private void dataGridView1_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)
{
    // hardcoded cell index
    if (e.ColumnIndex == 2 && e.RowIndex == 1)
    {
        // draw the background and disable the drawing
        e.PaintBackground(e.ClipBounds, true);
        e.Handled = true;

        // set the size of the cell
        dataGridView1.Rows[1].Height = textControl1.Height;
        dataGridView1.Columns[2].Width = textControl1.Width;

        // create the bitmap
        Bitmap bmp = new Bitmap(textControl1.Width, textControl1.Height);
        textControl1.DrawToBitmap(bmp, new Rectangle(0, 0,
            textControl1.Width, textControl1.Height));

        // draw the bitmap to the cell
        e.Graphics.DrawImage(bmp, new Point(e.CellBounds.X, e.CellBounds.Y));
    }
}