We Keep Coding

Add double quotes to a list to display in a label

Morning folks,
I have an ASP.Net C# page that pulls in a list of servers from a SQL box and displays the list of servers in a label. ("srv1,srv2,srv3"). I need to add double quotes around each of the servers names. ("srv1","srv2","srv3",)
Any help would be greatly appreached.

If you have string
string str = "srv1,srv2,srv3";
Then you can simply do
str = "\"" + str.Replace(",", "\",\"") + "\"";
Now str contains "srv1","srv2","srv3"

As far as I can understand, you are trying to use double quotes in a string.
If you want to use such,
you can use escape character:
("\"srv1\",\"srv2\",\"srv3\"",)
for the sake of simplicity, you can even convert it to a function:
private string quoteString(string serverName){
return "\"" + serverName + "\"";
}
Also, if you have already "srv1,srv2,srv3" format, find ',' characters in the string and add " before and after comma. Also, notice that you should add to first index and last index ".

C# Regex Replacement Not Working

I'm trying to remove new lines from a text file. Opening the text file in notepad doesn't reveal the line breaks I'm trying to remove (it looks like one big wall of text), however when I open the file in sublime, I can see them.
In sublime, I can remove the pattern '\n\n' and then the pattern '\n(?!AAD)' no problem. However, when I run the following code, the resulting text file is unchanged:
public void Format(string fileloc)
{
string str = File.ReadAllText(fileloc);
File.WriteAllText(fileloc + "formatted", Regex.Replace(Regex.Replace(str, "\n\n", ""), "\n(?!AAD)", ""));
}
What am I doing wrong?

If you do not want to spend hours trying to re-adjust the code for various types of linebreaks, here is a generic solution:
string str = File.ReadAllText(fileloc);
File.WriteAllText(fileloc + "formatted",
Regex.Replace(Regex.Replace(str, "(?:\r?\n|\r){2}", ""), "(?:\r?\n|\r)(?!AAD)", "")
);
Details:
A linebreak can be matched with (?:\r?\n|\r): an optional CR followed with a single obligatory LF. To match 2 consecutive linebreaks, a limiting quantifier can be appended - (?:\r?\n|\r){2}.

An empirical solution. Opening your sample file in binary mode revealed that it contains 0x0D characters, which are carriage returns \r. So I came up with this (multiple lines for easier debugging):
public void Format(string fileloc)
{
var str = File.ReadAllText(fileloc);
var firstround = Regex.Replace(str, #"\r\r", "");
var secondround = Regex.Replace(firstround, #"\r(?!AAD)", "");
File.WriteAllText(fileloc + "formatted", secondround);
}

Is this possibly a windows/linux mismatch? Try replacing '\r\n' instead.

Extract sub-string between two certain words right to left side

Example String
This is an important example about regex for my work.
I can extract important example about regex with this (?<=an).*?(?=for) snippet. Reference
But i would like to extract to string right to left side. According to this question's example; first position must be (for) second position must be (an).
I mean extracting process works back ways.
I tried what i want do as below codes in else İf case, but it doesn't work.
public string FnExtractString(string _QsString, string _QsStart, string _QsEnd, string _QsWay = "LR")
{
if (_QsWay == "LR")
return Regex.Match(_QsString, #"(?<=" + _QsStart + ").*?(?=" + _QsEnd + ")").Value;
else if (_QsWay == "RL")
return Regex.Match(_QsString, #"(?=" + _QsStart + ").*?(<=" + _QsEnd + ")").Value;
else
return _QsString;
}
Thanks in advance.
EDIT
My real example as below
#Var|First String|ID_303#Var|Second String|ID_304#Var|Third String|DI_t55
When i pass two string to my method (for example "|ID_304" and "#Var|") I would like to extract "Second String" but this example is little peace of my real string and my string is changeable.

No need for forward or backward lookahead! You could just:
(.*)\san\s.*\sfor\s
The \s demands whitespace, so you don't match an import*an*t.

One potential problem in your current solution is that the string passed in contains special characters, which needs to be escaped with Regex.Escape before concatenation:
return Regex.Match(_QsString, #"(?<=" + Regex.Escape(_QsStart) + ").*?(?=" + Regex.Escape(_QsEnd) + ")").Value;
For your other requirement of matching RL, I don't understand your requirement.

How do I replace all the spaces with %20 in C#?

I want to make a string into a URL using C#. There must be something in the .NET framework that should help, right?

Another way of doing this is using Uri.EscapeUriString(stringToEscape).

I believe you're looking for HttpServerUtility.UrlEncode.
System.Web.HttpUtility.UrlEncode(string url)

I found useful System.Web.HttpUtility.UrlPathEncode(string str);
It replaces spaces with %20 and not with +.

To properly escape spaces as well as the rest of the special characters, use System.Uri.EscapeDataString(string stringToEscape).

As commented on the approved story, the HttpServerUtility.UrlEncode method replaces spaces with + instead of %20.
Use one of these two methods instead: Uri.EscapeUriString() or Uri.EscapeDataString()
Sample code:
HttpUtility.UrlEncode("https://mywebsite.com/api/get me this file.jpg")
//Output: "https%3a%2f%2fmywebsite.com%2fapi%2fget+me+this+file.jpg"
Uri.EscapeUriString("https://mywebsite.com/api/get me this file.jpg");
//Output: "https://mywebsite.com/api/get%20me%20this%20file.jpg"
Uri.EscapeDataString("https://mywebsite.com/api/get me this file.jpg");
//Output: "https%3A%2F%2Fmywebsite.com%2Fapi%2Fget%20me%20this%20file.jpg"
//When your url has a query string:
Uri.EscapeUriString("https://mywebsite.com/api/get?id=123&name=get me this file.jpg");
//Output: "https://mywebsite.com/api/get?id=123&name=get%20me%20this%20file.jpg"
Uri.EscapeDataString("https://mywebsite.com/api/get?id=123&name=get me this file.jpg");
//Output: "https%3A%2F%2Fmywebsite.com%2Fapi%2Fget%3Fid%3D123%26name%3Dget%20me%20this%20file.jpg"

I needed to do this too, found this question from years ago but question title and text don't quite match up, and using Uri.EscapeDataString or UrlEncode (don't use that one please!) doesn't usually make sense unless we are talking about passing URLs as parameters to other URLs.
(For example, passing a callback URL when doing open ID authentication, Azure AD, etc.)
Hoping this is more pragmatic answer to the question: I want to make a string into a URL using C#, there must be something in the .NET framework that should help, right?
Yes - two functions are helpful for making URL strings in C#
String.Format for formatting the URL
Uri.EscapeDataString for escaping any parameters in the URL
This code
String.Format("https://site/app/?q={0}&redirectUrl={1}",
Uri.EscapeDataString("search for cats"),
Uri.EscapeDataString("https://mysite/myapp/?state=from idp"))
produces this result
https://site/app/?q=search%20for%20cats&redirectUrl=https%3A%2F%2Fmysite%2Fmyapp
Which can be safely copied and pasted into a browser's address bar, or the src attribute of a HTML A tag, or used with curl, or encoded into a QR code, etc.

Use HttpServerUtility.UrlEncode

HttpUtility.UrlDecode works for me:
var str = "name=John%20Doe";
var str2 = HttpUtility.UrlDecode(str);
str2 = "name=John Doe"

HttpUtility.UrlEncode Method (String)

The below code will replace repeating space with a single %20 character.
Example:
Input is:
Code by Hitesh Jain
Output:
Code%20by%20Hitesh%20Jain
Code
static void Main(string[] args)
{
Console.WriteLine("Enter a string");
string str = Console.ReadLine();
string replacedStr = null;
// This loop will repalce all repeat black space in single space
for (int i = 0; i < str.Length - 1; i++)
{
if (!(Convert.ToString(str[i]) == " " &&
Convert.ToString(str[i + 1]) == " "))
{
replacedStr = replacedStr + str[i];
}
}
replacedStr = replacedStr + str[str.Length-1]; // Append last character
replacedStr = replacedStr.Replace(" ", "%20");
Console.WriteLine(replacedStr);
Console.ReadLine();
}

HttpServerUtility.HtmlEncode
From the documentation:
String TestString = "This is a <Test String>.";
String EncodedString = Server.HtmlEncode(TestString);
But this actually encodes HTML, not URLs. Instead use UrlEncode(TestString).

What is the easiest way in C# to trim a newline off of a string?

I want to make sure that _content does not end with a NewLine character:
_content = sb.ToString().Trim(new char[] { Environment.NewLine });
but the above code doesn't work since Trim seems to not have an overloaded parameter for a collection of strings, only characters.
What is the simplest one-liner to remove an Enivronment.Newline from the end of a string?

The following works for me.
sb.ToString().TrimEnd( '\r', '\n' );
or
sb.ToString().TrimEnd( Environment.NewLine.ToCharArray());

.Trim() removes \r\n for me (using .NET 4.0).

How about:
public static string TrimNewLines(string text)
{
while (text.EndsWith(Environment.NewLine))
{
text = text.Substring(0, text.Length - Environment.NewLine.Length);
}
return text;
}
It's somewhat inefficient if there are multiple newlines, but it'll work.
Alternatively, if you don't mind it trimming (say) "\r\r\r\r" or "\n\n\n\n" rather than just "\r\n\r\n\r\n":
// No need to create a new array each time
private static readonly char[] NewLineChars = Environment.NewLine.ToCharArray();
public static string TrimNewLines(string text)
{
return text.TrimEnd(NewLineChars);
}

Use the Framework. The ReadLine() method has the following to say:
A line is defined as a sequence of
characters followed by a line feed
("\n"), a carriage return ("\r") or a
carriage return immediately followed
by a line feed ("\r\n"). The string
that is returned does not contain the
terminating carriage return or line
feed.
So the following will do the trick
_content = new StringReader(sb.ToString()).ReadLine();

What about
_content = sb.ToString().Trim(Environment.NewLine.ToCharArray());

_content = sb.TrimEnd(Environment.NewLine.ToCharArray());
This will of course remove "\r\r\r\r" as well as "\n\n\n\n" and other combinations.
And in "enviroments" where NewLine is other than "\n\r" you might get some strange behaviors :-)
But if you can live with this then I belive this is the most effectiv way to remove new line characters at the end of a string.

How about just:
string text = sb.ToString().TrimEnd(null)
That will pull all whitespace characters from the end of the string -- only a problem if you wanted to preserve non-newline whitespace.

Somewhat of a non-answer, but the easiest way to trim a newline off of a string is to not have the newline on the string in the first place, by making sure it is is never seen by your own code. That is, by using native functions which remove the newline. Many stream and file/io methods will not include the newline if you ask for output line by line, though it may be necessary to wrap something in a System.IO.BufferedStream.
Things like System.IO.File.ReadAllLines can be used in place of System.IO.File.ReadAllText most of the time, and ReadLine can be used instead of Read once you are working with the right type of stream (e.g. BufferedStream).

As Markus pointed out TrimEnd is doing the job now. I needed to get line feeds and white space from both ends of string in Windows Phone 7.8 environment. After having chased different more complex options my problem was solved by using Trim() only - passed the following tests nicely
[TestMethod]
[Description("TrimNewLines tests")]
public void Test_TrimNewLines()
{
Test_TrimNewLines_runTest("\n\r testi \n\r", "testi");
Test_TrimNewLines_runTest("\r testi \r", "testi");
Test_TrimNewLines_runTest("\n testi \n", "testi");
Test_TrimNewLines_runTest("\r\r\r\r\n\r testi \r\r\r\r \n\r", "testi");
Test_TrimNewLines_runTest("\n\r \n\n\n\n testi äål., \n\r", "testi äål.,");
Test_TrimNewLines_runTest("\n\n\n\n testi ja testi \n\r\n\n\n\n", "testi ja testi");
Test_TrimNewLines_runTest("", "");
Test_TrimNewLines_runTest("\n\r\n\n\r\n", "");
Test_TrimNewLines_runTest("\n\r \n\n \n\n", "");
}
private static void Test_TrimNewLines_runTest(string _before, string _expected)
{
string _response = _before.Trim();
Assert.IsTrue(_expected == _response, "string '" + _before + "' was translated to '" + _response + "' - should have been '" + _expected + "'");
}

I had to remove the new lines all over the text. So I used:
while (text.Contains(Environment.NewLine))
{
text = text.Substring(0, text.Length - Environment.NewLine.Length);
}