Can i access DrawContext variable globally? ( in any class of my app)

Question

My programming skills are not too good and em still very amateur at C# i would like to ask about Draw_Context what i am doing here is finding out angle between the joint ... what i wanted to do is when then angle comes between 70 and 90 timer starts and using Drawcontext.DrawText method show any message on the screen but as you can see i can't access the draw variable in on_time_event if i try to introduce a new variable of DrawContext and assign value of draw to it ... it gives and exception ... because new variable of Draw context never assigned a value what should i do? Please Please any help in this regard i will be very helpful

 class angle
  {
    System.Timers.Timer timer = new System.Timers.Timer();
    bool timer_start = false;
    int index = 5; 
    public DrawingContext draw_contex;


  public void angle_between_left_shoulder(Skeleton sk1, DrawingContext draw, JointType    
  Shoulder_cntre, 
        JointType Shoulder_left, JointType Elbow_left, KinectSensor sen)
    {

        //draw_contex= draw;
        Joint sh_cntr = sk1.Joints[Shoulder_cntre];
        Joint sh_left = sk1.Joints[Shoulder_left];
        Joint elb_left = sk1.Joints[Elbow_left];

        Vector3 v_shoulder = new Vector3(sh_cntr.Position.X, sh_left.Position.Y, 
        sh_cntr.Position.Z);
        Vector3 v_should_l = new Vector3(sh_left.Position.X, sh_left.Position.Y, 
        sh_left.Position.Z);
        Vector3 v_elbow_l = new Vector3(elb_left.Position.X, elb_left.Position.Y, 
        elb_left.Position.Z);

        Vector3 va = v_shoulder - v_should_l;
        Vector3 vb = v_elbow_l - v_should_l;

        va = Vector3.Normalize(va);
        vb = Vector3.Normalize(vb);

        float len_prod = va.Length() * va.Length();
        float dot_pro = Vector3.Dot(va, vb);
        double angle = Math.Acos(dot_pro);

        angle = angle * 180 / Math.PI;
        angle = 180 - angle;

        System.Windows.Point shoul_l = this.point_toScreen(sh_left.Position, sen);
        draw.DrawText(new FormattedText(angle.ToString("0"), new 
         System.Globalization.CultureInfo("en-us"),
         FlowDirection.LeftToRight,
         new Typeface("Verdana"), 16, Brushes.OrangeRed),
         new System.Windows.Point(shoul_l.X+10, shoul_l.Y +20));

        if (angle > 70 && angle < 90)
        {
            if (timer_start == false)
            {

                timer.Interval = 2000;
                timer.Start();
                timer.Elapsed += new ElapsedEventHandler(on_time_event);




            }
        }
    }

    void on_time_event(object sender, ElapsedEventArgs e)
     {
      --index;
       if (index != 0)
       {

        MessageBox.Show(index.ToString());

        /*
         draw_contex.DrawText(new FormattedText(index.ToString("0"), new 
        System.Globalization.CultureInfo("en-us"),
             FlowDirection.LeftToRight,
             new Typeface("Verdana"), 16, Brushes.OrangeRed),
             new System.Windows.Point(10, 120));
       }
      else
       {
        timer.Stop();
       }

Answer 1

If you're looking to simply display a formatted string in your window, you can write to a TextBlock. In your XAML, you'll have something along the lines of:

<Grid>
  <!-- whatever other controls you have -->
  <TextBlock Name="MyMessage" />
</Grid>

Then in your code-behind you can just write a new string to the TextBlock:

MyMessage.Text = "You moved too soon!";

You can just as easily format a string and send it to that as well.

Also, if my answer in your previous question on this subject was useful please accept it. It would be appreciated! :) body joints angle using kinect (checking time interval)