private void compareFile(object sender, EventArgs e) { if (listView1.SelectedItems.Count > 0) { var item = listView1.Items[listView1.SelectedItems[0].Index].Tag as FileEntry; if (item.Status == EntryStateEnum.Modified) { string beforeFilePath = Path.Combine(txtFileBefore.Text, item.FileName); string afterFilePath = Path.Combine(txtFileAfter.Text, item.FileName); CompareFile form = new CompareFile(File.ReadAllText(beforeFilePath), File.ReadAllText(afterFilePath)); form.Text = string.Format("Compare {0} with {1}", beforeFilePath, afterFilePath); form.Show(); } } }