ArcGIS Pro 2.7 API Reference Guide
SetTextProperties Method
Example 

ArcGIS.Desktop.Layouts Namespace > TextElement Class : SetTextProperties Method
TextProperties
Sets the TextProperties for a TextElement. This method must be called on the MCT. Use QueuedTask.Run.
Syntax
public void SetTextProperties( 
   TextProperties textProperties
)
Public Sub SetTextProperties( _
   ByVal textProperties As TextProperties _
) 

Parameters

textProperties
TextProperties
Exceptions
ExceptionDescription
This method or property must be called within the lambda passed to QueuedTask.Run.
Example
//Update text element properties for an existing text element.

// Reference a layoutitem in a project by name
LayoutProjectItem layoutItem = Project.Current.GetItems<LayoutProjectItem>().FirstOrDefault(item => item.Name.Equals("MyLayout"));
if (layoutItem != null)
{

  //Perform on the worker thread
  QueuedTask.Run(() =>
  {
    // Reference and load the layout associated with the layout item
    Layout layout = layoutItem.GetLayout();
    if (layout != null)
    {
      // Reference a text element by name
      TextElement txtElm = layout.FindElement("MyTextElement") as TextElement;
      if (txtElm != null)
      {
        // Change placement properties
        txtElm.SetAnchor(Anchor.CenterPoint);
        txtElm.SetX(x);
        txtElm.SetY(y);

        // Change TextProperties
        TextProperties txtProperties = new TextProperties("Hello world", "Times New Roman", 48, "Regular");
        txtElm.SetTextProperties(txtProperties);
      }
    }
  });
}
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

TextElement Class
TextElement Members