iPhone - GestureRecognizer sometimes doesn't fire?

I am trying to get a long key press on a button working in objective c for iPhone.

Here is the code I have put together for the GestureRecognizer:

    UILongPressGestureRecognizer *longPressGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPress:)];
    longPressGesture.minimumPressDuration = 1.0; //1 second
    longPressGesture.delegate = self;
    [deleteButton addGestureRecognizer:longPressGesture];
    [longPressGesture release];

And here is the function that I use in the selector to call when a long key press is detected.

-(void)handleLongPress:(UILongPressGestureRecognizer *) gestureRecognizer
{
    if (gestureRecognizer.state == UIGestureRecognizerStateBegan) {
        NSLog(@"Got handle long key press");
        NumLabel.text = @"";

    }

}

I开发者_如何学运维 have also added the following functions as part of my delegate class but they don't seem to have had any impact:

-(BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer{

    return YES;
}

-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{

    return NO;

}

-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch{

    return YES;

}

My issue is that this sometimes works but then again sometimes it doesn't, most of the time I get the call to handleLongPress and it works fine but every so often when the button is pressed and held down I get nothing until I lift my finger off the button at which stage my normal code for the button is run.

Have I missed something in the tutorials or can anyone spot why it would work sometimes but I get nothing on other occasions?

EDIT

I actually think the issue is with the way the button is pressed, if I press the button straight on and hold it then it works fine, however if my finger slips on the button even a little bit then the handleLongPress function isn't called.

I'm assuming this is because it recognizes it as a separate gesture? Is there a way to make sure that handleLongPress gets called as long as the button is held down even if the finger moves across the button at all?

Gesture recognizers are only for TOUCHES, not for button states. A Long press is really just pressing and releasing. When the touch moves, the gesture will be canceled!!
If you just want to know if your button is pressed more than a specific time, you can handle TouchDown/TouchCancel events of your button and add some timing.

Yes we can implement gesture recognizer along with the buttons. here it goes:

UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressButton:)]; [someButtonName addGestureRecognizer:longPress]; longPress.minimumPressDuration = 2.0; //longPress.delegate = self; [longPress release];

use it where you are creating your button aur in the method where you want to implement it.and then

- (void)longPressButton:(UILongPressGestureRecognizer*)gesture { if ( gesture.state == UIGestureRecognizerStateEnded) { NSLog(@"Long Pressed"); //your stuff here when detected long hold } }