Read, Write And Delete Text File Content Using C#

Today, I am going to show you a small demo of how to read, write and delete the text file content in listbox, using C# Window Application.

 

Step1

Create one empty text file and named it as your desired name and add into your project, as shown below.

 

Step 2

Create a form design. Here, I have added one textbox, one list box and three button events to add, delete and view the content from the text file.

 

 

Step3

Just add it, using System.IO; namespace in your Server side coding.

 

Now, begin writing the code for each button event. 

 

Add the new line to the text file.

 

Just write the code given below in an ADD button event. 

// Declare the File Information
FileInfo file = new FileInfo(@ "C:\Users\shekhart\documents\visual studio 2013\study\Demo\Demo\Demo.txt");
// write the line using streamwriter
using(StreamWriter sw = file.AppendText()) {
    sw.WriteLine(textBox1.Text);
}
// Read the content using Streamreader from text file
using(StreamReader sr = file.OpenText()) {
    string s = "";
    while ((s = sr.ReadLine()) != null) {
        listBox1.Text = s; // Display the text file content to the list box
    }
    sr.Close();
}

Delete the line from the text file

 

Write the code given below in Delete button event and while executing, just click the lines which you want to delete from the listbox.  

string path = @ "C:\Users\shekhart\documents\visual studio 2013\study\Demo\Demo\Demo.txt";
string word = Convert.ToString(listBox1.SelectedItem); // delete the selected line
var oldLines = System.IO.File.ReadAllLines(path);
var newLines = oldLines.Where(line => !line.Contains(word));
System.IO.File.WriteAllLines(path, newLines);
FileStream obj = new FileStream(path, FileMode.Append);
obj.Close();
// once deleted the selected line and once again read the text file and diplay the new text file in listBox
FileInfo fi = new FileInfo(@ "C:\Users\shekhart\documents\visual studio 2013\study\Demo\Demo\Demo.txt");
using(StreamReader sr = fi.OpenText()) {
    string s = "";
    while ((s = sr.ReadLine()) != null) {
        listBox1.Text = s;
    }
    sr.Close();
}
FileStream obj1 = new FileStream(path, FileMode.Append);
obj1.Close();

View the entered content from the text file

Now, write code to view the content of the text file in listBox  or you can write this code on page load event, so you can view the content while loading the page. 

string[] lines = System.IO.File.ReadAllLines(@ "C:\Users\shekhart\documents\visual studio 2013\study\Demo\Demo\Demo.txt");
foreach(string line in lines) // Read all line from the text file
{
    listBox1.Items.Add(line);
}

The output would be, as shown below.