How to maintain format of ".rtf" file after save?

Question

Hello and thank you for taking your time. I have been facing some problems with my project for a while regarding the
LoadFile  method . I have a project in Which I can can select several things and show them in a different
RichTextBox. Now, through the press of a button I can Save the contents of that of That
RichTextBox (The contents are formatted as in they have Bolded Text) in a
Rich Text File (.rtf) . I implemented the method of saving through creating a function called "WriteInFile" which writes the Boxes` contents in a ".rtf" file.  This is The code :
public void writeInFile(String name)
name = "Your Program";
name = String.Concat(name, ".rtf");
file = name;
TextWriter tw = new StreamWriter(@name);
tw.WriteLine(textBox1.Text);
foreach (var line in richTextBox1.Lines)
tw.WriteLine(line);
tw.Close();
Then I load "Your Program.rtf " through  the press of a different button, in the
same RichTextBox using the following code :
private void button4_Click_1(object sender, EventArgs e)
richTextBox1.LoadFile("Your Program.rtf", RichTextBoxStreamType.PlainText);
My problem is that when I load the file I want it tokeep its format,with bold etc. If I use the same code but insert ".RichText" It says that the format is invalid
(throws an exception) using ".PlainText" is fine ,also using a ".txt" format is fine it is just that
the format is not kept . I really do not know how to solve this...
Thank you for your time!

Answer 1

Try a different way:
// save:
richTextBox1.SaveFile(name, RichTextBoxStreamType.RichText);
// load:
richTextBox1.LoadFile(name, RichTextBoxStreamType.RichText);