How to Add Another Event Handler Method

Learn how to install an Event Handler on other Command Button.

We have one last thing that we need to add to this application and it has to do with the second button on the webpage. So, if you go into the design model, remember we have installed an event handler for this button but we have not yet installed an event handler for this button visited last year. Let us do that now. Select visited last year on the page and click the event icon here and fully click event. Now, if you select from the drop down list, you can choose the existence of end handler method in the blue button underscore click. Okay and then double click the event name. So, here is the event handler, let us just make this a bit bigger so we could see what is going on. So this event handler button blue button underscore click is now actually handling the click event for two different buttons. So what we would really like to do is to output a differently formatted message depending on whether we are displaying on the countries visited by the user this year or last year. Now, to do that, we need to somehow differentiate between the two buttons. The sender prompter indicates which control – in our example, a button – generated the event. It is always represented as type object so probably the first to do in the code is to convert that into a button variable. That is declared a button variable and I have called it sender button. We will assign it. The sender prompter converted into a button they detected. This variable now identifies which particular button generated the event and we can make in this statement to generate the trend to say either this year or last year depending on which button it was. Let us declare this off a helper variable called year message and let us make ourselves a statement to test which button the user click. Now, in this moment, we have to ask ourselves which property on the sender button object do we test. One possibility is to test the text attribute and I could do that. I could say take the button that was clicked and have a look at its text property. Let us just remind myself what the text properties were. The first text property was visited this year, so I could test to see if the text property is visited this year. If it is, then I can assign the year message to be some text such as this year. Alternatively, if the sender button text is visited last year, then I can set the year message to be something like last year. Then what we will do is we will change the result label so that it says, “These are the countries visited by the person’s name.” I am just going to get rid of these breakpoints so we can actually see what we are doing a bit more clearly here. Counties visited by persons name and then I will add a set of curly brackets and that set of curly brackets will be filled in by the value of our helper variable year message.