101 Rx Examples

I'm reading http://www.introtorx.com, which like the name suggests appears to be a concise introduction. There appear to be quite a lot of (very basic) examples, step-by-step, mostly using the console to print stuff out.

To start with - Here is a simple drawing application, so that when the user drags, we draw a red line from the initial mouse down position to the current location, and also a blue spot at the current location. This is the result of my last week's hack on Rx

And here is the source code.

//A draw on drag method to perform the draw
void DrawOnDrag(Canvas e)
        {

            //Get the initial position and dragged points using LINQ to Events
            var mouseDragPoints = from md in e.GetMouseDown()
                                  let startpos=md.EventArgs.GetPosition(e)
                                  from mm in e.GetMouseMove().Until(e.GetMouseUp())
                                  select new
                                  {
                                      StartPos = startpos,
                                      CurrentPos = mm.EventArgs.GetPosition(e),
                                  };


            //Subscribe and draw a line from start position to current position
            mouseDragPoints.Subscribe
                (item =>
                {
                    e.Children.Add(new Line()
                    {
                        Stroke = Brushes.Red,
                        X1 = item.StartPos.X,
                        X2 = item.CurrentPos.X,
                        Y1 = item.StartPos.Y,
                        Y2 = item.CurrentPos.Y
                    });

                    var ellipse = new Ellipse()
                    {
                        Stroke = Brushes.Blue,
                        StrokeThickness = 10,
                        Fill = Brushes.Blue
                    };
                    Canvas.SetLeft(ellipse, item.CurrentPos.X);
                    Canvas.SetTop(ellipse, item.CurrentPos.Y);
                    e.Children.Add(ellipse);
                }
                );
        }

Read my post with further explanation here and Download the source code here

Hope this helps

Another useful resource may be the Reactive Extensions (Rx) Koans: 55 progressive examples to help you learn Rx