Read \r sent by serial port in C#?

I'm sending a text by serial port to C#. This text contains \r and it will become a new line in HyperTerminal. Now I want to read this \r in C#. How can I do this?

    private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e)
    {
        RxString = serialPort1.ReadLine();

        this.Invoke(new EventHandler(DisplayText));
    }

    private void DisplayText(object sender, EventArgs e)
    {
        string str = RxString;

        if(str == "\r")
        {
            MessageBox.Show("This is a new line");
        }
    }