Highlight duplicate question in MS Word Document in C# Windows Form

Hi PRA,

Refer the below code.

private void btnUpload_Click(object sender, EventArgs e)
{
    DialogResult result = openFileDialog1.ShowDialog();
    if (result == DialogResult.OK)
    {
        Microsoft.Office.Interop.Word.Application word = new Microsoft.Office.Interop.Word.Application();
        Document doc = new Document();
        string filePath = openFileDialog1.FileName;//Environment.CurrentDirectory.Substring(0, Environment.CurrentDirectory.IndexOf("bin")) + "Files\\Test.doc";
        object missing = System.Type.Missing;
        object fileName = filePath;
        doc = word.Documents.Open(ref fileName,
                ref missing, ref missing, ref missing, ref missing,
                ref missing, ref missing, ref missing, ref missing,
                ref missing, ref missing, ref missing, ref missing,
                ref missing, ref missing, ref missing);
        List<string> data = new List<string>();
        for (int i = 0; i < doc.Paragraphs.Count; i++)
        {
            string temp = doc.Paragraphs[i + 1].Range.Text.Trim();
            if (temp != string.Empty)
                data.Add(temp);
        }
        var duplicateQuestions = data.Where(x => x.Contains("@")).Select(y => y.Split('.')[1].Trim()).GroupBy(x => x).Where(z => z.Count() > 1).Select(k => k.Key);
        foreach (string item in duplicateQuestions)
        {
            int count = 0;
            for (int i = 0; i < doc.Paragraphs.Count; i++)
            {
                string temp = doc.Paragraphs[i + 1].Range.Text.Trim();
                if (temp.Split('.').Length > 1)
                {
                    if (item == temp.Split('.')[1].Trim())
                    {
                        count++;
                    }
                    if (item == temp.Split('.')[1].Trim() && count > 1)
                    {
                        doc.Paragraphs[i + 1].Range.Font.ColorIndex = Microsoft.Office.Interop.Word.WdColorIndex.wdRed;
                    }
                }
            }
        }
        doc.Save();
        doc.Close(ref missing, ref missing, ref missing);
        ((_Application)word).Quit();
    }
}

Screenshot