Here are the steps:

Step 1: Open a blank app and add two TextBlocks and a button either from the toolbox or by copying the following XAML code into your grid.
  1. <StackPanel Margin="10,40,0,0">
  2. <TextBlock Text="Type the word to find" ></TextBlock>
  3. <TextBox Name="textToFind" Width="200" Margin="0,10,0,0" HorizontalAlignment="Left"></TextBox>
  4. <TextBlock Text="Type or Copy and Paste a sentence to find from " Margin="0,10,0,0" ></TextBlock>
  5. <TextBox Name="sentence" Height="100" Width="300" HorizontalAlignment="Left" Margin="0,10,0,0" TextWrapping="Wrap"></TextBox>
  6. <Button Name="find" Content="Find" Height="40" Width="120" Click="find_Click" Margin="0,10,0,0" ></Button>
  7. <TextBlock Name="result" TextWrapping="Wrap" Width="300" HorizontalAlignment="Left"></TextBlock>
  8. </StackPanel>


Step 2: Add the following namespaces to your project which is needed in further C# code.
  1. using System.Collections.Generic;
  2. using Windows.Data.Text;
  3. using Windows.UI.Text;
  4. using Windows.UI.Xaml.Documents;

Step 3: Copy and paste the following code to the cs page which will be called on button click event and the corresponding text will be highlighted.

  1. private void find_Click(object sender, RoutedEventArgs e)
  2. {
  3. result.Text = "";
  4. var mySemanticTextQuery = new Windows.Data.Text.SemanticTextQuery(textToFind.Text);
  5. IReadOnlyList<Windows.Data.Text.TextSegment> ranges = mySemanticTextQuery.Find(sentence.Text);
  6. HighlightRanges(result, sentence.Text, ranges);
  7. }
  9. public void HighlightRanges(TextBlock tb, String TextContent, IReadOnlyList<TextSegment> ranges)
  10. {
  11. int currentPosition = 0;
  12. foreach (var range in ranges)
  13. {
  14. if (range.StartPosition > currentPosition)
  15. {
  16. int length = (int)range.StartPosition - currentPosition;
  17. var subString = TextContent.Substring(currentPosition, length);
  18. tb.Inlines.Add(new Run() { Text = subString });
  19. currentPosition += length;
  20. }
  21. var boldString = TextContent.Substring((int)range.StartPosition, (int)range.Length);
  22. tb.Inlines.Add(new Run() { Text = boldString, FontWeight = FontWeights.Bold });
  23. currentPosition += (int)range.Length;
  24. }
  25. if (currentPosition < TextContent.Length)
  26. {
  27. var subString = TextContent.Substring(currentPosition);
  28. tb.Inlines.Add(new Run() { Text = subString });
  29. }
  30. tb.Inlines.Add(new Run() { Text = "\r\n" });
  31. }

Step 4: Run your application and test yourself.