MACROMEDIA COLDFUSION MX 7.0.2-USING COLDFUSION MX WITH FLEX 2 Guia do Utilizador descarregar pdf (Página 147)

Associate the listener with an event with MXML 147

The keyword public specifies the function’s scope. In this case, the function is available

throughout your code.

The keyword

void specifies the function’s return type. All ActionScript functions should

specify a return type. The

convertCurrency function returns no value.

The price entered by the user,

txtPrice.text, is cast as a number and then validated to

make sure the user entered a number. If the price is a number, the calculation is performed

and the result is cast back to a string for display in the lblResults control.

In a real-world application, the value of the rate variable would be set at run time by

calling a web service and retrieving the current exchange rate. As well, the result would be

formatted as a currency.

4. Save the file.

Associate the listener with an event with

MXML

Associating a listener to an event, or registering it, means to include logic in your application

that notifies the listener of a triggering event of a particular type from a particular source. For

your application, you want the event listener to be notified of a click event from the Convert

to Yen button. When notified that the event has occurred, the listener performs the currency

calculation and displays the results.

One way to register the listener is to specify it as the value of the

click property in the

<mx:Button> tag.

You can also use ActionScript to register the listener. For more information, see “Associate the

listener with an event with ActionScript” on page 148.

1. In Design mode, select the Button control and enter convertCurrency() in the On Click

text box in the Properties view.

1 2 ... 142 143 144 145 146 147 148 149 150 151 152 ... 255 256

Sem comentários

MACROMEDIA COLDFUSION MX 7.0.2-USING COLDFUSION MX WITH FLEX 2 Guia do Utilizador Página 147