get a line after a specific word from text file

darma teja

Hi All,

In my text file I have data like this:

[data]
123.txt
blabla

[Mobile]
345.txt
456.txt
[calls]
vsjs.txt
dsfs.txt

I would like to get these data (345.txt, 456.txt) and and the keyword to get is "[Mobile]".

I want to show 345.txt, 456.txt in rich textbox. If user makes any changes than I want to save it back. It means If user writes 345test.txt then the text file should be like this:

[data]
123.txt
blabla

[Mobile]
345test.txt
456.txt
[calls]
vsjs.txt
dsfs.txt

Advance thanks,
Darma

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes12y ago
Accepted answer
The following code assumes that there is only one [Mobile] section in the file and that the relevant lines will be loaded to the RTB when button1 is pressed and any changes saved when button2 is pressed:

using System.IO;

// ....

private string filePath = @"c:\myfiles\somefile.txt"; // or whatever it is
private string[] lines;
private int startIndex;
private string originalText = "";
private int originalCount;

private void button1_Click(object sender, EventArgs e)
{
lines = File.ReadAllLines(filePath);
var mobileLines = new List();
startIndex = -1;

for(int i = 0; i < lines.Length; i++)
{
if (lines[i].StartsWith("[Mobile]"))
{
startIndex = i + 1;
}
else if(lines[i].StartsWith("[") && startIndex > -1)
{
break;
}
else if(startIndex > -1)
{
mobileLines.Add(lines[i]);
}
}

if(mobileLines.Count > 0)
{
richTextBox1.Lines = mobileLines.ToArray();
originalText = richTextBox1.Text;
originalCount = mobileLines.Count;
}
}

private void button2_Click(object sender, EventArgs e)
{
if (richTextBox1.Text != originalText)
{
var allLines = lines.ToList();
allLines.RemoveRange(startIndex, originalCount);
allLines.InsertRange(startIndex, richTextBox1.Lines);
File.WriteAllLines(filePath, allLines);
}
}
0
darma teja12y ago
Thanks allot Vulpes!
0
Vulpes12y ago
Just in case the user decides to make some changes and press button2, then make some more changes and press button2 again, I'd add some lines to the button2_Click handler:

private void button2_Click(object sender, EventArgs e)
{
if (richTextBox1.Text != originalText)
{
var allLines = lines.ToList();
allLines.RemoveRange(startIndex, originalCount);
allLines.InsertRange(startIndex, richTextBox1.Lines);
File.WriteAllLines(filePath, allLines);
lines = allLines.ToArray();
originalText = richTextBox1.Text;
originalCount = richTextBox1.Lines.Length;
}
}

I'd also disable button2 until button1 has been pressed.
0