How to read from a text file line by line?

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Hello, I need to read from a text file.

There are only 2 lines in the text file. And I need to read both, line by line as a string. After reading it, I want to use it (concatenate).

For example, each line is represented as string1 and string2. I will concatenate to make a sentence like

"Your number is " + string1 + " and your port is " + string2".

My question is, how do I do it? I read it as array? And convert it to string? Or vice versa?

I'm really confused.

Thanks in advance.

Posted 15-Nov-10 2:44am

Little Daffodil

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thatraja 15-Nov-10 9:23am

I mentioned in my answer like "Use Stringbuilder with below example"

thatraja 15-Nov-10 9:32am

Hi, check my updated answer for sample code

Little Daffodil 15-Nov-10 9:35am

ok, i need to understand the stringbuilder 1st.. ill get back to this post later.
thanks thatraja!

2 solutions

Solution 3

C#

public static string MyMethod(string filename)
{
    string result = string.Empty;
    try
    {
        string[] lines = File.ReadAllLines(filename);
        result = "Your number is " + lines[0] + " and your port is " + lines[1] + ".";
    }
    catch (FileNotFoundException e)
    {
        // Deal with it!
    }
    catch (IndexOutOfRangeException e)
    {
        // Deal with it too! (there aren't two lines in the file)
    }
    // Catch other possible Exceptions here!
    return result;
}

Posted 15-Nov-10 8:50am

Toli Cuturicu

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thatraja · Accepted Answer · 2010-11-15T02:53:00

Solution 1

Use Stringbuilder with below example...that's all

C# Read Text File Line-by-Line[^]

Stringbuilder sample code

C#

StringBuilder sb = new StringBuilder();
int count = lines1.Length;
for (int i = 0; i < count; i++)
{
string line = lines1[i];
sb.AppendLine(line);
}
Console.WriteLine(sb.ToString());

Posted 15-Nov-10 2:53am

thatraja

Updated 15-Nov-10 3:31am

v2

Comments

thatraja 15-Nov-10 9:21am

[Comment from OP][Moved from Answer]
Thanks thatraja.
But the code only displays both lines..

Now, I want to use the string and concatenate it. How do I do that?

Thanks.

Little Daffodil 18-Nov-10 8:46am

thatraja, this is what I'm trying to do:

using (StreamReader sr = File.OpenText(@"C:config.txt"))
{
String input;
string[] lines = new string[2];
while ((input = sr.ReadLine()) != null)
{
int i;
if ((input = sr.ReadLine()) != null)
{
for (i = 0; i < 2; i++)
{
input = lines[i];
}
MessageBox.Show("COM Port is " + lines[0]);
MessageBox.Show("Phone number is " + lines[1]);
}
}

}

However, it's not working. MessageBox does not appear the comport and phone number. :-(
My main problem now is how do I assign each line read from the file as a string variable.. Please help.

Thanks.

(btw, from my reading, i still dont quite get the concept of stringbuilder :-( )

Little Daffodil 18-Nov-10 8:55am

I've managed to get what I want. This is my code:

using (StreamReader sr = File.OpenText(@"C:\config.txt"))
{

String input;
string[] lines = File.ReadAllLines(@"C:\config.txt");
while ((input = sr.ReadLine()) != null)
{
int i;
// if ((input = sr.ReadLine()) != null)
for (i = 0; i < 2; i++)
{
input = lines[i];
}
}
MessageBox.Show("COM Port is " + lines[0]);
MessageBox.Show("Phone number is " + lines[1]);
}

thatraja 18-Nov-10 9:16am

Put the message box inside the loop. Create 2 variables like sNumber, sPort assign the array values to these variables then concatenate with your string. That's all.
Actually I shouldn't confused you by including the string-builder in this issue, apologize.