In this recipe, we will learn how to add and use toolbars within our application.
In this recipe, we will discuss the usage of the Toolbar object and how we can use the associated properties to display an animated progress bar.
In order to see how this can be achieved, we need to modify our ViewObjectsExample application that we created in the previous recipe. Perform the following steps to do so:
- Open the
ViewObjectsExample.xcodeprojproject file. - Select the
ViewController.xibfile from the project navigator window. - From Object Library, drag a Toolbar object into the main view controller, and place it at the top of the main view.
- Next, select the button it contains by default and set its Title property to Fade In.
- Next, add a
Flexible Space Bar Button Itemobject to the toolbar to the right of the Fade In button. - Then, from Object Library, drag a UIBarButtonItem object to the toolbar and place this after the
Flexible Space Bar Button Itemobject. - Next, select the button and set its Title property to Fade Out.
- Next, create the outlets and properties for the Fade In and Fade Out buttons, and name them
btnFadeInandbtnFadeOut. - Next, create the action methods for the Fade In and Fade Out buttons, and name them
viewFadeInandviewFadeOut. - After creating the button outlets and properties, save the document by selecting File | Save from the menu bar, or alternatively by pressing command + S. The layout should look like the following screenshot:
Our next step is to create the code functionality that will be responsible for updating the label to display what button was pressed within the toolbar:
- Open the
ViewController.mimplementation file from the project navigator. - Modify the
viewFadeInandviewFadeOutmethods, as shown in the following code snippet:- (IBAction)viewFadeIn:(UIBarButtonItem *)sender { lblInfo.text = @"Fade In button clicked."; } - (IBAction)viewFadeOut:(UIBarButtonItem *)sender { lblInfo.text = @"Fade Out button clicked."; } - Then, build and run the application by selecting Product | Run from the Product menu, or alternatively by pressing command + R.
When the compilation completes, the iOS Simulator will appear. Tap on both of the toolbar buttons to see the label update based on which button has been clicked.
The UIToolbar object is used to hold items relating to the UIBarButtonItem object type. These types of objects are special kinds of buttons and spacers. A UIBarButtonItem object can be system defined or custom type, and can use any of the predefined types as listed in the Identifier attribute within Interface Builder and provides a specific icon to the button.
The UIBarButtonItem objects can also be customized to contain an image to make your application more
professional and visually intuitive. This can be achieved by using the Image attribute within Interface Builder.