searching a textfile for a keyword

I have a text file with names as balamurugan,chendu开发者_StackOverflowrpandian,...... if i give a value in the textbox as ba ....

If i click a submit button means i have to search the textfile for the value ba and display as pattern matched....

I have read the text file using

 string FilePath = txtBoxInput.Text;

and displayed it in a textbox using

  textBoxContents.Text = File.ReadAllText(FilePath);

But i dont know how to search a word in a text file using c# can anyone give suggestion???

You can simply use:

textBoxContents.Text.Contains(keyword)

This will return true if your text contains your chosen keyword.

Depends upon the kind of pattern matching that you needs - you can use as simple as String.Contains method or can try out Regular Expressions that will give you more control on how you want to search and give all matches at the same time. Here are couple of links to get you started quickly on regular expressions:

http://www.codeproject.com/KB/dotnet/regextutorial.aspx http://www.developer.com/open/article.php/3330231/Regular-Expressions-Primer.htm

First, you should split up the input string, after which you could do a contains on each value:

// On file read:
String[] values = File.ReadAllText(FilePath);

// On search:
List<String> results = new List<String>();
for(int i = 0; i < values.Length; i++) {
    if(values[i].Contains(search)) results.Add(values[i]);
}

Alternatively, if you only want it to search at the beginning or the end of the string, you can use StartsWith or EndsWith, respectively:

// Only match beginnging
values[i].StartsWith(search);
// Only match end
values[i].EndsWith(search);