add string after filename in c#

var files = Directory.GetFiles(@"C:\yourFolder", "*.pdf"); string prefix = "SomePrefix"; foreach (var file in files) { string newFileName = Path.Combine(Path.GetDirectoryName(file), (prefix + Path.GetFileName(file))); File.Move(file, newFileName); } 

tep 1 : as a first step identify wether the file exists or not before copying the file.
using File.Exists() method

Step 2: if the file already exists with same name then delete the existing file using File.Delete()method

Step 3: now copy the File into the new Location using File.Copy() method.

Step 4: Rename the newly copied file.

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