How to search and get line in the textbox, using C#

Question

0.00/5 (No votes)

See more:

Hello, I have a list data in textbox. Example:
35480745295701728, 416433146831396068 || Carrien
35480709562394675, 379026073325960916 || Lean
96154183216121221, 515151515159611872 || Sunailo
18151851515151818, 815618181215187187

I want to search and show a line on windows form C#. Please help!
Example: search 35480709562394675. It will be show: 35480709562394675, 379026073325960916 || Lean

Thank you very much!

What I have tried:

System.IO.StreamReader ObjReader;
                ObjReader = new System.IO.StreamReader(File_name);

do
       {                    

         Textline = Textline + ObjReader.ReadLine();
         if (Textline.Contains(flag) == true)
         {
             for (int i = 0; i < txtInput.Lines.Length; i++)
               {
                //wrong somethings
               }
         else
         {
            lblOutput.Text = txtInput.Text + " : NOT FOUND";
         }
      }

      while (ObjReader.Peek() != -1);
      ObjReader.Close();

Posted 3-Jun-19 11:26am

phannhatthanh1510

Updated 4-Jun-19 8:01am

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Answer 1 · 2019-06-03T20:10:00

It's difficult to work out exactly what that code is supposed to do, but it's somewhat muddled at best.
You are adding each line you read to TextLine, regardless of what it contains:

Textline = Textline + ObjReader.ReadLine();

You then check that to see if contains a value:

if (Textline.Contains(flag) == true)

If it does, you loop through each character in an unrelated and unchanging string:

for (int i = 0; i < txtInput.Lines.Length; i++)

And ... do nothing with it:

{
 //wrong somethings
}

If it doesn't, you set the output to a "Not Found" message, but showing somethgin your didn't search for:

lblOutput.Text = txtInput.Text + " : NOT FOUND";

And then you go round and to it again for the next line!
If you are trying to find a line that contains a specific value, then sit down and think about it:
1) Set a flag to say "not found".
2) Loop through each line
2.1) If the line contains the text then
2.1.1) Set the "found flag"
2.1.2) Save the line
2.1.3) Exit the loop (hint: break is handy here)
3) After the loop, check the "found" flag
3.1 If it's set, show the line
3.2 If it's still "not found", report an error.

Me? I'd use File.ReadAllLines[^] and then use a foreach loop to make it easier to read.

phannhatthanh1510 · Answer 2 · 2019-06-04T08:02:00

Thank you very much! It's working with this

string File_name = @"E:\Data.txt";
            string flag = txtInput.Text.Trim(); 
            string[] readText = File.ReadAllLines(File_name);
            foreach (string s in readText)
            {               
                if ((s.Contains(txtInput.Text) == true))
                {
                    richTextBox1.Text = s.ToString();
                    break;                   
                }
                else
                {
                    richTextBox1.Text = "Not Found";
                }
            }

How to search and get line in the textbox, using C#

2 solutions

Solution 1

Solution 2

Add your solution here

Preview 0