WPF RichTextBox：AppendText、TextRange 和尾随换行符

Question

I am reading a text file's contents into a RichTextBox like this:

string contents = File.ReadAllText("MyFile.txt");
myRichTextBox.Document.Blocks.Clear();
myRichTextBox.AppendText(contents);

I am using the RichTextBox to automatically apply some syntax highlighting of sorts. When I try reading the unformatted text as described here to save it back to the file, things happen:

1. A newline (\r\n) is added to the back of the file, which I don't want unless the user explicitly adds this newline.
2. When I load the file again, the newline is not displayed in the RichTextEdit, even if it is present in the file.

How can I change this, so that the RichTextBox displays and returns exactly the contents of the text file?

Answer 1

Could this work? contents.Replace("\r\n", "\n");

Answer 2

The newline \r\n (CR/LF) is part of the text formatting in the RichTextBox control. Each paragraph while converting to the text will be appended by the \r\n .

This is means when a user press the ENTER button a new paragraph with \r\n is adding to the RichTextBox control. And when StringFromRichTextBox() method, described in the Microsoft documentation is used to extract the text content from a RichTextBox it will return a string in which all paragraphs are separated by the \r\n .

The explanations regarding the comments above:

A newline (\r\n) is added to the back of the file, which I don't want unless the user explicitly adds this newline.

A newline \r\n is adding to the end of the file only as a part of the each paragraph ending.

NOTE: If it is necessary to save and thereafter to load the saved document the TextRange.Save() and TextRange.Load() methods can be used:

public void SaveRtf(RichTextBox rtb, string file)
{
    var range = new TextRange(rtb.Document.ContentStart, rtb.Document.ContentEnd);
    using (var stream = new StreamWriter(file))
    {
        range.Load(stream.BaseStream, DataFormats.Rtf);
    }
}

public void LoadRtf(RichTextBox rtb, string file)
{
    var range = new TextRange(rtb.Document.ContentStart, rtb.Document.ContentEnd);
    using (var stream = new StreamWriter(file))
    {
        range.Save(stream.BaseStream, DataFormats.Rtf);
    }
}

If to save the whole RuchTextBox content the new TextRange(rtb.Document.ContentStart, rtb.Document.ContentEnd).Text will be used than any text formatting after restoring will be lost.