Develop Reference

Append Text at exact location in text

I was looking to append text to a exact location in a text file. I have used StreamReader to find the text in the file I am looking for. I thought about using StreamWriter but that obviously doesn't make sense. I was hoping to find some "append" method in some class somewhere that would help me do this but with now success. Or is there a better way to do this than to use StreamReader?
using (StreamReader sr = new StreamReader(fileName))
{
string line;
while ((line = sr.ReadLine()) != null)
{
if (line.Contains("VAR_GLOBAL CONSTANT"))
{
//append text before this variable
// e.g. (*VAR_GLOBAL CONSTANT
// append the (* before VAR_GLOBAL CONSTANT
}
if (line.Contains("END_VAR"))
{
//append text after this variable
// e.g. END_VAR*)
// append the *) after END_VAR
}
}
}
Does anyone have any thoughts on how to accomplish this?

One way to do it would be to read the file contents into a string, update the contents locally, and then write it back to the file again. This probably isn't very feasible for really large files, especially if the appending is done at the end, but it's a start:
var filePath = #"f:\public\temp\temp.txt";
var appendBeforeDelim = "VAR_GLOBAL CONSTANT";
var appendAfterDelim = "END_VAR";
var appendBeforeText = "Append this string before some text";
var appendAfterText = "Append this string after some text";
var newFileContents = File.ReadAllText(filePath)
.Replace(appendBeforeDelim, $"{appendBeforeText}{appendBeforeDelim}")
.Replace(appendAfterDelim, $"{appendAfterDelim}{appendAfterText}");
File.WriteAllText(filePath, newFileContents);

How can I read Persian line in csv file c#

I want to read a simple CSV file with comma separated with this code:
var reader = new StreamReader(File.OpenRead(#"d:\34.csv"));
List<string> listA = new List<string>();
List<string> listB = new List<string>();
while (!reader.EndOfStream)
{
var line = reader.ReadLine();
var values = line.Split(',');
listA.Add(values[0]);
listB.Add(values[1]);
}
MessageBox.Show("READ IT!!!");
But when I read the file an debug that code,attention can not read Persian or Arabic character! How can I solve that? I think my file is not valid encoding?

if your CSV file contains just one line the ReadToEnd could be acceptable, but if you have a log file composed by more than one line then it is better to read line by line using ReadLine of the StreamReader object
link for true answer and more information
using (StreamReader sr = new StreamReader("c:/temp/34.csv"))
{
string currentLine;
// currentLine will be null when the StreamReader reaches the end of file
while((currentLine = sr.ReadLine()) != null)
{
// Search, case insensitive, if the currentLine contains the searched keyword
if(currentLine.IndexOf("I/RPTGEN", StringComparison.CurrentCultureIgnoreCase) >= 0)
{
Console.WriteLine(currentLine);
}
}
}
More information

You can create a class composed of get and set for each line of the CSV . You can then instantiate an object list to retrieve the CSV lines.
Try this way :
class Program
{
static void Main(string[] args)
{
var reader = new StreamReader(File.OpenRead(#"YourCSV"),Encoding.Unicode);
List<Customer> customer = new List<Customer>();
while (!reader.EndOfStream)
{
Customer c = new Customer
{
m_line1 = null,
m_line2 = null,
};
var line = reader.ReadLine();
var tokens = line.Split(',');
c.m_line1 = tokens[0];
c.m_line2 = tokens[1];
customer.Add(c);
}
foreach(var s in customer)
{
Console.Writline(s);
Console.Readline();
}
}
}
class Customer
{
private string line1;
public string m_line1
{
get
{
return line1;
}
set
{
line1= value;
}
}
private string line2;
public string m_line2
{
get
{
return line2;
}
set
{
line2= value;
}
}

You will have to pass the character encoding to the StreamReader constructor. There is no such thing as plain text. Reading text requires knowing its encoding.
The line
using (StreamReader sr = new StreamReader("c:/temp/34.csv"))
should be
using (StreamReader sr = new StreamReader("c:/temp/34.csv"), myencoding)
what myencoding is is something only you can know. With what encoding was the file saved? That's the encoding you need there. If the file was generated on Windows, and educated guess of the most likely encoding would be it is UTF-16LE. That encoding is available as Encoding.Unicode - which is a bad name, it should have been Encoding.UTF16LE, but that's the name the .NET framework uses.
Other possible encodings that are supported by StreamReader are listed on https://msdn.microsoft.com/en-us/library/System.Text.Encoding_properties(v=vs.110).aspx
If you don't know with what encoding the file was saved, some encodings leave hints in the form of a Byte order mark sometimes abbreviated to BOM. A byte order mark are the first few bytes of a text document that tell you its encoding. You can find more information on the byte order mark, and some of its values on http://en.wikipedia.org/wiki/Byte_order_mark
Relying on the BOM is generally a bad idea, because
it's not a full-proof solution: some encodings don't use a BOM, or make the BOM optional
Even if you successfully determine the encoding, that doesn't mean that StreamReader knows how to handle that encoding (though this is unlikely, but possible)
the BOM might not be a BOM at all, but be part of the actual text (also unlikely but possible)
In some cases it is impossible to know the encoding of a file, notably if the file comes from a file upload on the web, or if someone just mailed you the file, and they don't know how they encoded it. This can be a good reason not to allow "plain text" uploads (which is reasonable because, it can do with a little repetition, there is no such thing as plain text).
tl;dr: The most likely thing to work is one of
using (StreamReader sr = new StreamReader(File.OpenRead(#"c:/temp/34.csv"),Encoding.Unicode) {
...
}
or
using (StreamReader sr = new StreamReader(File.OpenRead(#"c:/temp/34.csv"),Encoding.UTF8)
or
using (StreamReader sr = new StreamReader(File.OpenRead(#"c:/temp/34.csv"),Encoding.UTF32)

Read text file from C# Resources

I need to read a file from my resources and add it to a list.
my code:
private void Form1_Load(object sender, EventArgs e)
{
using (StreamReader r = new StreamReader(Assembly.GetExecutingAssembly().GetManifestResourceStream("myProg.myText.txt")))
{
//The Only Options Here Are BaseStream & CurrentEncoding
}
}
Ive searched for this and only have gotten answers like "Assembly.GetExecutingAssembly...." but my program doesnt have the option of Assembly.?

Try something like this :
string resource_data = Properties.Resources.test;
List<string> words = resource_data.Split(new[] {Environment.NewLine}, StringSplitOptions.RemoveEmptyEntries).ToList();
Where

You need to include using System.Reflection; in your header in order to get access to Assembly. This is only for when you mark a file as "Embedded Resource" in VS.
var filename = "MyFile.txt"
System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream("YourNameSpace." + filename));
As long as you include 'using System.Reflection;' you can access Assembly like this:
Assembly.GetExecutingAssembly().GetManifestResourceStream("YourNamespace." + filename);
Or if you don't need to vary filename just use:
Assembly.GetExecutingAssembly().GetManifestResourceStream("YourNamespace.MyFile.txt");
The full code should look like this:
using(var reader = new StreamReader(Assembly.GetExecutingAssembly().GetManifestResourceStream("myProg.m‌​yText.txt"))
{
string line;
while ((line = reader.ReadLine()) != null)
{
// Do some stuff here with your textfile
}
}

Just to follow on this, AppDeveloper solution is the way to go.
string resource_data = Properties.Resources.test;
string [] words = resource_data.Split(new[] {Environment.NewLine}, StringSplitOptions.RemoveEmptyEntries);
foreach(string lines in words){
.....
}

[TestCategory("THISISATEST")]
public void TestResourcesReacheability()
{
byte[] x = NAMESPACE.Properties.Resources.ExcelTestFile;
string fileTempLocation = Path.GetTempPath() + "temp.xls";
System.IO.File.WriteAllBytes(fileTempLocation, x);
File.Copy(fileTempLocation, "D:\\new.xls");
}
You get the resouce file as a byte array, so you can use the WriteAllBytes to create a new file. If you don't know where can you write the file (cause of permissions and access) you can use the Path.GetTempPath() to use the PC temporary folder to write the new file and then you can copy or work from there.

C# - Appending text files

I have code that reads a file and then converts it to a string, the string is then written to a new file, although could someone demonstrate how to append this string to the destination file (rather than overwriting it)
private static void Ignore()
{
System.IO.StreamReader myFile =
new System.IO.StreamReader("c:\\test.txt");
string myString = myFile.ReadToEnd();
myFile.Close();
Console.WriteLine(myString);
// Write the string to a file.
System.IO.StreamWriter file = new System.IO.StreamWriter("c:\\test2.txt");
file.WriteLine(myString);
file.Close();
}

If the file is small, you can read and write in two code lines.
var myString = File.ReadAllText("c:\\test.txt");
File.AppendAllText("c:\\test2.txt", myString);
If the file is huge, you can read and write line-by-line:
using (var source = new StreamReader("c:\\test.txt"))
using (var destination = File.AppendText("c:\\test2.txt"))
{
var line = source.ReadLine();
destination.WriteLine(line);
}

using(StreamWriter file = File.AppendText(#"c:\test2.txt"))
{
file.WriteLine(myString);
}

Use File.AppendAllText
File.AppendAllText("c:\\test2.txt", myString)
Also to read it, you can use File.ReadAllText to read it. Otherwise use a using statement to Dispose of the stream once you're done with the file.

Try
StreamWriter writer = File.AppendText("C:\\test.txt");
writer.WriteLine(mystring);

C# Using Lists to read, write and search text file lines

I need to perform the following operations with a text file and a List:
Read all lines of text file (non delimited) into a string based list
Whilst the application is open I need to do the following:
Check for instances of a string in the List
Add new entries to the List
Remove all identical instances of a defined string from the List
Write the contents of the List back to the text file including any changes made as soon as they are made
Firstly, how do I read and write between Lists and text files?
Secondly, how do I search a List for a string?
Lastly, how do I safely remove an item out of a List without leaving gaps in the text file I write?

public void homework()
{
string filePath = #"E:\test.txt";
string stringToAdd = "test_new";
IList readLines = new List();
// Read the file line-wise into List
using(var streamReader = new StreamReader(filePath, Encoding.Default))
{
while(!streamReader.EndOfStream)
{
readLines.Add(streamReader.ReadLine());
}
}
// If list contains stringToAdd then remove all its instances from the list; otherwise add stringToAdd to the list
if (readLines.Contains(stringToAdd))
{
readLines.Remove(stringToAdd);
}
else
{
readLines.Add(stringToAdd);
}
// Write the modified list to the file
using (var streamWriter = new StreamWriter(filePath, false, Encoding.Default))
{
foreach(string line in readLines)
{
streamWriter.WriteLine(line);
}
}
}
Try to google before you post the question.

I'd start here:
Read from text file: http://dotnetperls.com/readline
List Actions
1. Removing from a list
2. Searching in a List
Write to a text file: http://www.csharp-station.com/HowTo/ReadWriteTextFile.aspx

I'll just share my idea...
using System.IO;
public void newMethod()
{
//get path of the textfile
string textToEdit = #"D:\textfile.txt";
//read all lines of text
List<string> allLines = File.ReadAllLines(textToEdit).ToList();
//from Devendra's answer
if (allLines.Contains(stringToAdd))
{
allLines.Remove(stringToAdd);
}
else
{
allLines.Add(stringToAdd);
}
//extra: get index and edit
int i = allLines.FindIndex(stringToEdit => stringToEdit.Contains("need to edit")) ;
allLines[i] = "edit";
//save all lines
File.WriteAllLines(textToEdit, allLines.ToArray());
}