Checking Them Out

To see how these work in practice, take a peek at (available from the Source Code section of the Apress Web site), containing the following layout:

and the following Java code:

Public class extends implements

Public onCreate

Super onCreate

SetContentView

FindViewById

SetOnClickListener this

FindViewById

SetOnClickListener this

Public onClick

If

New Builder this

SetTitle

SetMessage

SetNeutralButton new OnClickListener

Public onClick

// do nothing – it will close on its own

Show

Else

MakeText this

Show

The layout is unremarkable – just a pair of buttons to trigger the alert and the .

When the Raise an Alert button is clicked, we use a builder () to set the title (), message (), and neutral button () before showing the dialog. When the button is clicked, the callback does nothing; the mere fact the button was pressed causes the dialog to be dismissed. However, you could update information in your activity based upon the user action, particularly if you have multiple buttons for the user to choose from. The result is a typical dialog box like the one in Figure 14‑1.

Figure 14‑1. The MessageDemo sample application, after clicking the Raise an Alert button

When you click the Make a Toast button, the Toast class makes us a text‑based , which we then . The result is a short‑lived, non‑interrupting message (see Figure 14‑2).

Figure 14‑2. The same application, after clicking the Make a Toast button