Using the C1Document Class

As we mentioned earlier, the C1RichTextBox provides a linear, flat view of the control content, while C1Document class exposes the document structure.

To illustrate the advantages of working directly with the document object, suppose you wanted to add some functionality to the previous sample: when the user presses the CTRL key, you want to capitalize the text in all paragraphs of type Heading2.

The object model exposed by the C1RichTextBox is not powerful enough to do this reliably. You would have to locate spans based on their formatting, which would be inefficient and unreliable (what if the user formatted some plain text with the same format used by Heading2?).

Using the C1Document object model, this task becomes trivial:

Visual Basic	Copy Code
Public Sub New() ' Default initialization InitializeComponent() ' No changes here... ' Bind the second C1RichTextBox to the same document rtb2.Document = _rtb.Document AddHandler rtb2.KeyDown, AddressOf rtb2_KeyDown End Sub Private Sub rtb2_KeyDown(sender As Object, e As KeyEventArgs) If e.Key = Key.Ctrl Then For Each heading2 As var In _rtb.Document.Blocks.OfType(Of Heading2)() Dim text = heading2.ContentRange.Text heading2.ContentRange.Text = text.ToUpper() Next End If End Sub

Visual Basic

Copy Code

Public Sub New()
    ' Default initialization
    InitializeComponent()

    ' No changes here...

    ' Bind the second C1RichTextBox to the same document
    rtb2.Document = _rtb.Document
    AddHandler rtb2.KeyDown, AddressOf rtb2_KeyDown
End Sub
Private Sub rtb2_KeyDown(sender As Object, e As KeyEventArgs)
    If e.Key = Key.Ctrl Then
        For Each heading2 As var In _rtb.Document.Blocks.OfType(Of Heading2)()
            Dim text = heading2.ContentRange.Text
            heading2.ContentRange.Text = text.ToUpper()
        Next
    End If
End Sub

C#	Copy Code
public MainPage() { // Default initialization InitializeComponent(); // No changes here... // Bind the second C1RichTextBox to the same document rtb2.Document = _rtb.Document; rtb2.KeyDown += rtb2_KeyDown; } void rtb2_KeyDown(object sender, KeyEventArgs e) { if (e.Key == Key.Ctrl) { foreach (var heading2 in _rtb.Document.Blocks.OfType<Heading2>()) { var text = heading2.ContentRange.Text; heading2.ContentRange.Text = text.ToUpper(); } } }

Copy Code

public MainPage()
{
  // Default initialization
  InitializeComponent();

  // No changes here...

  // Bind the second C1RichTextBox to the same document
  rtb2.Document = _rtb.Document;
  rtb2.KeyDown += rtb2_KeyDown;
}
void rtb2_KeyDown(object sender, KeyEventArgs e)
{
  if (e.Key == Key.Ctrl)
  {
    foreach (var heading2 in _rtb.Document.Blocks.OfType<Heading2>())
    {
      var text = heading2.ContentRange.Text;
      heading2.ContentRange.Text = text.ToUpper();
    }
  }
}

The code monitors the keyboard. When the user presses the CTRL key, it enumerates all Heading2 elements in the document and replaces their content with capitals.

Doing the same thing using the C1RichTextBox object model would require a lot more code and the result would not be as reliable.