C#向字符串中添加一个字符

Question

I'm not new to C# and I work with strings all the time but I just can't understand why in this case I can't add a simple character to a simple string! I'm trying to read a text file into C# so that I can later insert it into a SQL server table. Anyway, I'm stuck on adding a single quote character to a string. My code is as follows:

string text;

using (var streamReader = new StreamReader(@"The_Directory\myTextFile.txt", Encoding.UTF8))
{
    text = streamReader.ReadToEnd();
}

string[] lines = text.Split(new Char[] { '\n' });
string rearrange;

foreach (string line in lines)
{
     rearrange = "*" + line + "'";
     Console.WriteLine(rearrange);  
}

What I get as a result doesn't contain the character that I wish to add to the end of the string and only contains the character that I wanted to add to the end, at the beginning.

The output is like this:

'The first line
'The second line

I can't understand why it doesn't perform the simple string addition. I tried to filter out any possible additional \\n character in the lines but it didn't help.

Answer 1

As pointed out by @Olivier, you are splitting on \\n rather than \\r\\n . That may mean there is still a \\r character ( carriage return ) at the end of every line you read. The resulting output is then:

*The first line\r'
*The second line\r'

which, on a typical terminal emulator, is displayed as:

'The first line
'The second line

If you could slow down the terminal output, you'd see the * is initially there at the start of the line, before being overwritten by the ' .

---

One way to get rid of the clutter is to strip off trailing whitespace:

rearrange = "*" + line.TrimEnd() + "'";

Note: None of this will work for files produced on a 'classic' Mac, where newline is a carriage return without linefeed. I'd recommend following Olivier's answer .

Answer 2

Just try this:

using System.IO;

string[] lines = File.ReadAllLines("The_Directory\myTextFile.txt", Encoding.UTF8);

string rearrange;

foreach (string line in lines)
{
  rearrange = "*" + line + "'";
  Console.WriteLine(rearrange);  
}

On Windows, new line is Environment.Newline = "\\r\\n" .

Splitting only on '\\n' causes that the remaining '\\r' implies a go to the start of the current line and the * is replaced by a ' when outputed to the console, hence the result.

Because the \\n historically in DOS causes the cursor only to go to down in the column, if I remember correctly, but I'm not sure, so the need of the \\r too.

https://fr.wikipedia.org/wiki/Carriage_Return_Line_Feed

Answer 3

Just try the following small modification in the "Split":

    string text;
    using (var streamReader = new StreamReader(@"The_Directory\myTextFile.txt",Encoding.UTF8))
    {
        text = streamReader.ReadToEnd();
    }

    string[] lines = text.Replace("\r\n","\n").Split("\n");
    string rearrange;
    foreach (string line in lines)
    {
        rearrange = "*" + line + "'";
        Console.WriteLine(rearrange);
    }

Usually, a normal (Windows) UTF-8 text file has both \\r\\n on the end of each line. If you split just by \\n, then the remaining \\r will remain and the result of displaying the \\r on the console is that the cursor jumps to the beginning of the current line, before displaying the next character. Thus, it would overwrite the line with the following characters while displaying further text.

Answer 4

2 Things. Try string.split with stringsplitoptions.RemoveEmptyEntries. And for the StringBuilding use a StringBuilder instead of concatenating it.