I want to print the content of my RichTextBox (eintragRichTextBox) I have now this code:
private void druckenPictureBox_Click(object sender, EventArgs e) {
It seems your code has a problem, it reprints the first page only because of the
StringReader reader = new StringReader(eintragRichTextBox.Text);
in your DocumentToPrint_PrintPage()
DocumentToPrint_PrintPage()