Since I am using a background image, none of these solutions worked well for me. Here is a solution that does some fun objective-c magic and offers a drop in solution with minimal code.
First, add a category to UIButton that overrides the hit test and also adds a property for expanding the hit test frame.
UIButton+Extensions.h
@interface UIButton (Extensions)
@property(nonatomic, assign) UIEdgeInsets hitTestEdgeInsets;
@end
UIButton+Extensions.m
#import "UIButton+Extensions.h"
#import <objc/runtime.h>
@implementation UIButton (Extensions)
@dynamic hitTestEdgeInsets;
static const NSString *KEY_HIT_TEST_EDGE_INSETS = @"HitTestEdgeInsets";
-(void)setHitTestEdgeInsets:(UIEdgeInsets)hitTestEdgeInsets {
NSValue *value = [NSValue value:&hitTestEdgeInsets withObjCType:@encode(UIEdgeInsets)];
objc_setAssociatedObject(self, &KEY_HIT_TEST_EDGE_INSETS, value, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
-(UIEdgeInsets)hitTestEdgeInsets {
NSValue *value = objc_getAssociatedObject(self, &KEY_HIT_TEST_EDGE_INSETS);
if(value) {
UIEdgeInsets edgeInsets; [value getValue:&edgeInsets]; return edgeInsets;
}else {
return UIEdgeInsetsZero;
}
}
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
if(UIEdgeInsetsEqualToEdgeInsets(self.hitTestEdgeInsets, UIEdgeInsetsZero) || !self.enabled || self.hidden) {
return [super pointInside:point withEvent:event];
}
CGRect relativeFrame = self.bounds;
CGRect hitFrame = UIEdgeInsetsInsetRect(relativeFrame, self.hitTestEdgeInsets);
return CGRectContainsPoint(hitFrame, point);
}
@end
Once this class is added, all you need to do is set the edge insets of your button. Note that I chose to add the insets so if you want to make the hit area larger, you must use negative numbers.
[button setHitTestEdgeInsets:UIEdgeInsetsMake(-10, -10, -10, -10)];
Note: Remember to import the category (#import "UIButton+Extensions.h") in your classes.
Best Answer
Unfortunately, you can't use stretchable/resizable images in the current version of Xcode 4. You have to do it programmatically.
Assuming that you are talking about iOS 5: the SDK is still under NDA for a few days, so I can't be more specific. But just as a hint: Apple doesn't discourage the use of
stretchableImageWithLeftCapWidth:topCapHeight:. If you look at the documentation (iOS 5 version) of this method again, you will find an answer there.