RichTextBox颜色选中的行

SelectionColor在追加之前设置,例如:

    int line = 0;
    foreach (string file in myfiles)
    {
        // Whatever method you want to choose a color, here
        // I'm just alternating between red and blue
        richTextBox1.SelectionColor = 
            line % 2 == 0 ? Color.Red : Color.Blue;

        // AppendText is better than rtb.Text += ...
        richTextBox1.AppendText(file + "\r\n");
        line++;
    }