private void UpdateItemNames()
 {
     for (int i = 0; i < _selectedItemsIndices.Count; i++)
     {
         File currentFile = Files[_selectedItemsIndices[i]];
         currentFile.NewName = GetNewName(currentFile.OldName, i);
     }
     Files = new BindableCollection <File>(Files); // Forces an UI refresh.
 }
 public void RenameFiles()
 {
     try
     {
         for (int i = 0; i < _selectedItemsIndices.Count; i++)
         {
             File currentFile = Files[_selectedItemsIndices[i]];
             System.IO.File.Move(_dirPath + "/" + currentFile.OldName, _dirPath + "/" + currentFile.NewName);
         }
         MessageBox.Show(_selectedItemsIndices.Count.ToString() + " files successfully renamed.");
         UpdateList(Directory.GetFiles(_dirPath));
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.Message, "Error");
     }
 }