WPF- TextBox Control

Question

How can we calculate the width from the text of textbox control in WPF?

 

DoubleAnimation doubleAnimation = new DoubleAnimation();

doubleAnimation.From = -tbmarquee.ActualWidth;

doubleAnimation.To = canMain.ActualWidth;

doubleAnimation.RepeatBehavior = RepeatBehavior.Forever;

doubleAnimation.Duration = new Duration(TimeSpan.Parse("0:0:20"));

tbmarquee.BeginAnimation(Canvas.LeftProperty, doubleAnimation);

 

 

<Canvas ClipToBounds="True" Name="canMain" Grid.Column="0" Grid.Row="0">

<TextBlock FontSize="35" FontWeight="Bold" Foreground="#ffffe400" Margin="0,0,0,0" Name="tbmarquee"></TextBlock>

</Canvas>

 

tbmarquee.actualwidth giving 0 value 

 

please give me solution to find out the width of tbmarquee according to text