sastgroup.com - Tutorials guide scripts web tool

Molto spesso può capitare che durante lo sviluppo di un'app si abbia la necessità di creare un elemento grafico tramite programmazione. Nel tutorial di oggi imparerete come creare un UI button tramite programmazione.

 
// Create a Button
UIButton *myButton = [[UIButton buttonWithType: UIButtonTypeRoundedRect];
 
// To be notified when a button changes state, add a target and action:
[myButton addTarget:self action: @selector(buttonClick:) forControlEvents:UIControlEvent TouchUpInside];
 
// To create a button with a image
 
-(void)buttonDown:(id)sender
{
	NSLog(@"Button pushed down");
}
 
-(void)buttonRelease:(id)sender
{
	NSLog(@"Button released");
}
 
-(void)checkboxClick:(UIButton *)btn
{
	btn.selected = !btn.selected;
}
 
- (void)viewDidLoad {
 
    [super viewDidLoad];
 
	//rounded-rect button
	UIButton *roundedRectButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
 
	CGRect buttonRect = CGRectMake(100,50,100,35);
	[roundedRectButton setFrame:buttonRect];
 
	[roundedRectButton setTitle:@"Normal" forState:UIControlStateNormal];
	[roundedRectButton setTitle:@"Highlighted" forState:UIControlStateHighlighted];
	roundedRectButton.showsTouchWhenHighlighted = YES;
 
    [roundedRectButton addTarget:self action:@selector(buttonDown:) forControlEvents:UIControlEventTouchDown];
    [roundedRectButton addTarget:self action:@selector(buttonRelease:) forControlEvents:UIControlEventTouchUpInside];
 
	//checkbox control
	UIButton *checkbox = [UIButton buttonWithType:UIButtonTypeCustom];
 
	CGRect checkboxRect = CGRectMake(135,150,36,36);
	[checkbox setFrame:checkboxRect];
 
	[checkbox setImage:[UIImage imageNamed:@"checkbox_off.png"] forState:UIControlStateNormal];
	[checkbox setImage:[UIImage imageNamed:@"checkbox_on.png"] forState:UIControlStateSelected];
 
    [checkbox addTarget:self action:@selector(checkboxClick:) forControlEvents:UIControlEventTouchUpInside];
 
	//custom circular button
	UIButton *circularButton = [UIButton buttonWithType:UIButtonTypeCustom];
 
	CGRect circularRect = CGRectMake(80,220,165,164);
	[circularButton setFrame:circularRect];
 
	UIImage *buttonImage = [UIImage imageNamed:@"circular_button.png"];
	[circularButton setImage:buttonImage forState:UIControlStateNormal];
 
    [circularButton addTarget:self action:@selector(buttonDown:) forControlEvents:UIControlEventTouchUpInside];
 
	//add all the buttons to the main view
	[self.view addSubview:roundedRectButton];
	[self.view addSubview:checkbox];
	[self.view addSubview:circularButton];
}