I created an app that reads two columns from excel file and search for each file in column A. if file is found then it is renamed to what column b says and moved to a separate folder.

This part of the code that i am having issue, please help!!!

DirectoryInfo di = new DirectoryInfo(sourceFile);
FileInfo[] files = di.GetFiles(oldName, SearchOption.AllDirectories);

foreach (FileInfo file in files)
     file.MoveTo(destinationFile + @"\\" + newName);

In debugging mode:
this is what i see in each variable

sourceFile = "c:\test"
oldName = "128-421.jpg"
newName = "128.jpg"
di = "C:\\test"
files = {System.IO.FileInfo[0]}
file = Null

Why do i keep getting Null in variable file.

Hi there,

Here's some code that I hope it will help you.

// Folder path;
            string sourcePath = Application.StartupPath;

            DirectoryInfo di = new DirectoryInfo(sourcePath);

            // File name;
            string oldName = "file.txt";

            FileInfo[] files = di.GetFiles(oldName, SearchOption.TopDirectoryOnly);

            // Path to destination folder;
            string destinationPath = sourcePath + @"\Folder\";
            // New name of file;
            string newName = "newfile.txt";

            foreach (FileInfo file in files)
                file.MoveTo(destinationPath + newName);

This is having source folder where your executable runs,
Destination folder is a folder inside the source folder named 'Folder'.

And note, if you use @ you shouldn't escape the bar... Either use "\\" or @"\". Using @"\\" as in your code above will give you as result "\\" and that will give you an invalid path.
See some explanation about it here http://blogs.msdn.com/b/csharpfaq/archive/2004/03/12/what-does-an-before-the-start-of-a-string-literal-mean.aspx.