Working with Files in C#

This article was contributed by Anand Narayanaswamy.In this article, you will learn how to manipulate directories and files in your system. Further, we will discuss how to read from and write to a file by using the powerful .NET classes.

Get File Extension Using C#

private string getFileExtension(string fileName)
{

string extension=””;

char []arr=fileName.ToCharArray();

int index=0;

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

{

if(arr[i]==’.’)

{

index=i;

}

}

for(int x=index+1;x<arr.Length;x++)

{

extension=extension+arr[x];

}

return extension;

}

How to loop through all files in a folder using C#

// How much deep to scan. (of course you can also pass it to the method)
const int HowDeepToScan=4;

public static void ProcessDir(string sourceDir, int recursionLvl)
{
if (recursionLvl<=HowDeepToScan)
{
// Process the list of files found in the directory.

string [] fileEntries = Directory.GetFiles(sourceDir);
foreach(string fileName in fileEntries)
{
// do something with fileName
Console.WriteLine(fileName);
}

// Recurse into subdirectories of this directory.
string [] subdirEntries = Directory.GetDirectories(sourceDir);
foreach(string subdir in subdirEntries)
// Do not iterate through reparse points
if ((File.GetAttributes(subdir) & FileAttributes.ReparsePoint) != FileAttributes.ReparsePoint)
{
ProcessDir(subdir,recursionLvl+1);
}
}
}

Source: weblogs.asp.net