hold down the control key; click the File's Owner icon in thme main nib window
and keep the mouse button down.Drag away the File's Owner icon toward the
View window. A bule guideline should appear. Keep dragging util your cursor is over the label in the View window Even though you won't be able to see the lael
it willl magicallyapper once you over it
and a small gray menu like the one show in Figure should pop up.
Select statusText from the gray menu.
telling Interface Builder that you want to connect one of the File's Owner's
outlets to this Object when the nib file is loaded. In this case, the file's owner
is the class Button_FunViewController, and the
oulet point to the label,
Specifying Actions
using the connections inspector.
c2
More User Interface Fun
to tie a button control to a text label. controls to a whole new level.
an image view, a slider,two different text fields,
a segmented control, a couple of switches, and an IOS
button that looks more like, well, an ios button.
use the view hierarchy to group multiple items under a common parent
view and make manipulating the interface at runtime easier.
set and retrieve the values of various controls , both by using outlets
and by using the sender argument of our action methods.
using action sheets to force the user to make a choice and alerts to give the user important
the use of stretchable images
break our application into pieces,implementing our piece at a time and bouncing back and
forth between Xcode and the IOS simulator, testing each piece before we move
on to the nex
Dividing the process of building a complex interface into smaller
chunks make it much less intimidating ,
A Screen Full of Controls
The logo at the top of the iPhone screen is an image view,
and in this application , it does nothing more than display a static image
alphanumeric text and one that allows only numers.
Below the text fields ia a slider.
segmented control and two switches.
an action sheet pops up,asking users if thy really meant to tap the button.
Active, and Passive Controls
Uer interface controls come in three basic forms: active and passive
active controls.push them, and something happens, a piece of code fires
work in a passive manner, simply holding on to a value that the user has entered until you're
ready for it. dont't trigger action methods, but the user can interact with
them and change their values. text field on a web page.
the vast majority of web page text fields are simpl containers
for data that's submitted to the server when you click the sbmit button.
many of the available controls can be used in all both ways, depending on your needs.
All IOS controls are subclasses of UIControl and ,because of that are capable of triggering action methods
Ｃreating the Application
Control Fun.
The image must be imported into Xcode before it will be available for us inside IB,
import it now
itis a .png image sized correctly for the space available
Add the image to the Resources folder of your project, by dragging the image form the Finder to
the Resources folder
Determin Outlets
figure out which of these objects requires an outlet
remerber that outlets must be defined in your controller class's header file before you can connect them to anything in the ib edior.
The image view is just a static image.
that image won't change while our application is running.
As a result. It does not require an outlet.
If we want to change the image or any of its characteristics at runtime
we would need an outlet. That is not the case here.
use an outlet,
#import <UIKit/UIKit.h>
@interface Control_FunViewController : UIViewController {
UITextField *nameField;
UITextField *numberField;
}
@property (nonatomic, retain) IBOutlet UITextField *nameField;
@property(nonatomic, retain) IBOutlet UITextField *numberField;
@end
add our @synthesize directives to Control_FunViewController.m
#import "Control_FunViewController.h"
@implementation Control_FunViewController
@synthesize nameField;
@synthesize numberField;
careful about memor.
with the retain keyword, release them both in our dealloc method
- (void)dealloc {
[nameField release];
[numberField release];
[super dealloc];
}
Determing Actions
Building the Interface
select library from the Tools menu.
Resize the image View
the same size as your image.
to press c= to select Size to Fit from the layout menu
hierarchical View Mode button in the main nib window.
find and select the image view when it comes to resizing
hold down the option key
The Mode Attribute
pop-up menu labeled Mode
how the image will be aligned inside the view and whether
it will be scaled to fit.
display the same image at multipage sizes, generally it's etter to have
multiple copies of the image at different sizs in your project
The Alpha Slider
Alpha, how transparent your image is: how much of what's beneath
it shows through.
spend processor cycles calculating transparency.
Ignore the Background
The Tag Attribute
numeric value that you can set that will tag along with your image view
Tags provide an easy,language-independent way of identifying objects on your inerface.
a single action method to handle all five buttons.
button's title tags will never change, so if you set a tag value here in Inetvace
Builder, you can then use that as a fast and reliable way to check
which control was passed into an action method in the sender argument.
The Drawing checkboxes
The Drawing Checkboxes
a series of Drawing checkboxes. labeled Opaque
Adding the Text Field
The Text Field Inspector Settings
default value for this field.
Placeholder, specify a bit of text that will be displayed
in gray inside the text field,but only when the field has no
value.
Type in the text Type in a name as the placeholder for this text field.
the appearance of your text field,
to look a certain way.
Background and Disabled field and leave them blank.
Border four buttons.
the text field's edge will be drawn.
Clear When Editing Begins checkbos happens
when the user touches this field.
any value that was previously in this field will get deleted , and the user will
start with an empty field. If this box is unchecked, the prevos vlue
will stay in the field, and the user will be able to edit it.
Text Color field is a combination of a color well
Adjust to Fit checkbox specifies whether the size
of the text should shrink if the text firld is reduced in size
Text Input Traits
how th keyboard will look and behave when this text field is being used. Since we're expecting
a name, let's chagen the Capitalize drop-down to Words, which
will cause every word to be automatically capitalized, which
is what you typically want with names.
Return Key pop-up to Done