Part 4 - Form Events

Next we will need to handle some form events. When the user clicks the mouse on the form or presses a key it will cause the application to quit so copy and paste the fallowing code into Form1



We will also want the ability to drag a scent trail on the scene by using the mouse. To do this, set the player position to the position of the mouse as it moves across the form. Copy and paste the code below into Form1



Next we will need to perform a check to see if the form is closing so we can dispose of the variables we have declared. We do this using the FormClosing event. If the form is not being canceled we can clean up our variables by calling the DoCleanUp method. Copy and paste the code below into Form1



Finally we can add code to the forms Load event. Copy and paste the code below into Form1.



The first thing we do is resize the form so the it’s client area is 512 wide by 512 high. Second we create the player and position it in the center of the form, as well as set it’s size to 10. The next thing is to create the flies and scent collections.

Next we create our flies. But before we do that we create a new collection that will contain the flies Receptor’s. The Receptor collection will have two receptors added to it. The first receptor will be a distance of 10 from the position of the fly, and facing -45 degrees from the direction the fly is facing. We also specify that the receptor has a size value of 5. The second receptor is the same as the first except that it will be +45 Degrees to the right from the direction the fly is facing. Keep in mind that every fly in the scene will be referencing these same 2 receptors that were declared. Each fly does not hold it’s own unique collection of receptors.

Now that we have a collection of receptors we can begin creating the flies. Each new fly we create will be randomly placed on the form and given a random starting direction.

After the flies have been created we specify that we want to control the painting on the form by calling the SetStyle method. Second we need to specify the maximum size of the buffer we will be drawing to. And third we allocate a new BufferedGraphics object by calling the allocate method and passing in a new graphics object that was created by the form, as well as the area on the form we will be drawing to.

The next thing to do is create the timer objects. Each timer has been setup to begin running, and after the interval of time has elapsed will raise it’s Elapsed event once.