iPhone SDK - UIButton not working in custom view

Question

This is driving me nuts... I've seen a few posts on similar issues but can't seem to make it work, so here it is:

it is a very simple example, I am just creating a custom UIButton in a custom view, then assigning it a custom action to respond to touch events. When I run the app, the button is created, but nothing happens when I try to click it.

Here is the code for my custom class:

#import "MySegmentedControl.h"


@implementation MySegmentedControl
@synthesize button1;

- (id)initWithFrame:(CGRect)frame {
if ((self = [super initWithFrame:frame])) {


    CGFloat a = frame.origin.x+5;
    CGFloat b = frame.origin.y+5;
    CGFloat l = frame.size.width-15;
    CGFloat h = frame.size.height-15;

    CGFloat c = a+l;
    CGFloat d = b;

    CGRect frame2 = CGRectMake(a, b, l, h);


    UIButton *mybutton1 = [UIButton buttonWithType:UIButtonTypeCustom];
    mybutton1.frame = frame2;
    [mybutton1 setTitle:@"TEST" forState:UIControlStateNormal];
    mybutton1.titleLabel.textColor = [UIColor blackColor];
    mybutton1.backgroundColor = [UIColor blueColor];

    [mybutton1 addTarget:self action:@selector(action)forControlEvents:UIControlEventTouchUpInside];

    [self setButton1:mybutton1];

    self.userInteractionEnabled = YES;
    button1.userInteractionEnabled = YES;

    [self addSubview:button1];

    [self bringSubviewToFront:button1];


}

return self;
}

-(void)action {

    [button1 setTitle:@"done" forState:UIControlStateNormal];
    button1.backgroundColor = [UIColor greenColor];
    NSLog(@"Working!");

}

And here is the appDelegate:

#import "MySegmentedControlAppDelegate.h"
#import "MySegmentedControl.h"

@implementation MySegmentedControlAppDelegate

@synthesize window;


#pragma mark -
#pragma mark Application lifecycle

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    

    // Override point for customization after application launch.

    [window makeKeyAndVisible];

    MySegmentedControl *mycontrol = [[MySegmentedControl alloc] initWithFrame:CGRectMake(10,50,135,50)];

    [window addSubview:mycontrol];

    return YES;
}

as you can see from the custom class, from what I've read in other posts I've tried to add a few things to increase my chances of success:

• enabling the custom's view userinteraction
• bringing the UIButton to front
• making sure the button's frame is completely included in the view's frame
• ...

... yet it still doesn't work!...

Any help would be greatly appreciated - thanks!

Edit: here is also the header for the custom view:

#import <UIKit/UIKit.h>


@interface MySegmentedControl : UIView {

    UIButton *button1;
}

@property (nonatomic, retain) IBOutlet UIButton *button1;

- (void)action;

@end

Answer 1

Can you join the header file of your custom view too?

(Sorry to do that in answer, I don't just have enough reputation for the moment).

Edit (and real answer) :

I've build a projet similar to yours and I think I've find the problem.

Your button frame is not good. Look at this screenshot from simulator, custom UIView frame is in red (just add self.backgroundColor=[UIColor redColor]; in your view constructor) :

By using this code :

CGFloat a = frame.origin.x+5;
CGFloat b = frame.origin.y+5;
CGFloat l = frame.size.width-15;
CGFloat h = frame.size.height-15;

You refer at the frame in windows base coordinates ! So your button is outside of your view and it can't handle touch event.

If you want to place your button dynamically, you should use this :

CGFloat a = self.bounds.origin.x+5;
CGFloat b = self.bounds.origin.y+5;
GFloat l = self.bounds.size.width-15;
CGFloat h = self.bounds.size.height-15;

By using self.bounds you use view base coordinate and it's working (see screenshots below) !

Hope this helps !