Long Press Gesture and subview not working - iphone

Question

I have a UIView,with a subview of a UISCrollView with a subview of a view(lastView). What I wanted is when I long press the view it will remove the lastView. then after a long press again the lastView will appear again. I tried it, but I only got this far. My lastView isnt appearing and my long press gesture isnt working too.
Here is my code:
- (void)handleLongPress:(UILongPressGestureRecognizer*)sender {
if (sender.state == UIGestureRecognizerStateEnded) {
[self.slotView removeFromSuperview];
NSLog(#"Long press Ended");
}
else {
NSLog(#"Long press detected.");
}
}
- (void) createScrollView {
self.slotBg = [[UIView alloc] initWithFrame:CGRectMake(43, 370, 300, 143)];
CAGradientLayer *gradient = [CAGradientLayer layer];
gradient.frame = self.slotBg.bounds;
gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor grayColor] CGColor], (id)[[UIColor whiteColor] CGColor], nil];
[self.slotBg.layer insertSublayer:gradient atIndex:0];
[self.view addSubview:self.slotBg];
UILongPressGestureRecognizer *longPress =
[[UILongPressGestureRecognizer alloc] initWithTarget:self
action:#selector(handleLongPress:)];
longPress.minimumPressDuration = 2.0;
[slotBg addGestureRecognizer:longPress];
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0.0f,0.0f,300.0f,134.0f)];
[slotBg addSubview:scrollView];
self.slotView = [[UIView alloc] initWithFrame:CGRectMake(0.0f,0.0f,300.0f,134.0f)];
[scrollView addSubview:slotView];
int row = 0;
int column = 0;
for(int i = 0; i < _thumbs.count; ++i) {
UIImage *thumb = [_thumbs objectAtIndex:i];
UIButton * button = [UIButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(column*60+10, row*60+10, 60, 60);
[button setImage:thumb forState:UIControlStateNormal];
[button addTarget:self
action:#selector(buttonClicked:)
forControlEvents:UIControlEventTouchUpInside];
button.tag = i;
[scrollView addSubview:button];
if (column == 4) {
column = 0;
row++;
} else {
column++;
}
}
[scrollView setContentSize:CGSizeMake(330, (row+1) * 60 + 10)];
}

Answer 1

In view's touchesBegan: you can call your "long tap" handle with some delay.
[touchHandler performSelector:#selector(longTap:) withObject:nil afterDelay:1.5];
Then in view's touchesEnded: you can cancel that call if not enough time has passed:
[NSObject cancelPreviousPerformRequestsWithTarget:touchHandler selector:#selector(longTap:) object:nil];
Add bool *flag in .h file of view; and in viewDid load add this flag = true;
Now selector longTap: would be:
-(void)longTap:(id)sender
{
if(flag){
flag = false;
[lastView removeFromSuperView];
}
else{
flag = true;
//Create lastView reference
[scrollView addSubView:lastView];
}
}

Answer 2

Add UIGestureRecognizerDelegate and write [longPress setDelegate:self]; in - (void) createScrollView. I think it will helpful to you.