Unable to call touchesBegan/touchesMoved method inside viewController in iOS - ios

Question

I have a viewController which contains a UITableView. This viewController implements UITableViewDelegate, and UITableViewDataSource, and I'm also trying to implement the following methods:
touchesBegan
touchesMoved
touchesEnded
However, these methods are not being called. I am trying to call these methods in response to the user touching a UIImageView that is inside a UITableView, but doing so only calls this method:
- (void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[self.view bringSubviewToFront:_imageView];
[UIView animateWithDuration:.3 animations:^{
CGRect rect = [self.view convertRect:[tableView rectForRowAtIndexPath:indexPath] fromView:tableView];
CGFloat floatx = _imageView.frame.origin.x - rect.origin.x;
_imageView.frame = CGRectMake(rect.origin.x + floatx, rect.origin.y, _imageView.frame.size.width, _imageView.frame.size.height);
}];
NSLog(#"Table row %d has been tapped", indexPath.row);
}
What I am hoping is to continue to call this method, but also call:
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
if ([touch view] == _imageView) {
//need to make sure user can only move the UIImageView up or down
CGPoint location = [touch locationInView:_imageView];
//ensure UIImageView does not move outside UIITableView
CGPoint pt = [[touches anyObject] locationInView:_imageView];
CGRect frame = [_imageView frame];
//Only want to move the UIImageView up or down, not sideways at all
frame.origin.y += pt.y - _startLocation.y;
[_imageView setFrame: frame];
_imageView.center = location;
return;
}
}
when the user is dragging the UIImageView inside the UITableView.
Can anyone see what I am doing wrong?
Thanks in advance to all who reply

Answer 1

I had a similar problem to this except I was trying to implement touch detection to an UIWebView. I eventually got over it by adding a UIPanGestureRecognizer to the UIWebView's .view property.
Implement this method:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
return YES;
}
and then add the UIPanGestureRecognizer to the UITableView like so:
UIPanGestureRecognizer *panGesture;
panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(panGestureDetected:)];
panGesture.maximumNumberOfTouches = 1;
panGesture.minimumNumberOfTouches = 1;
panGesture.delegate = self;
[self.tableView addGestureRecognizer:panGesture];
and then implement the method
- (void)panGestureDetected:(UIPanGestureRecognizer *)recognizer {
}
Now, every time the UIPanGestureRecognizer detects a pan gesture, it will call that method and you can get the location of the UIPanGestureRecognizer by calling the method [recognizer locationInView:self.tableView.view]; which will return a CGPoint. You can also get the state of the UIPanGestureRecognizer by calling [recognizer state] which returns a UIGestureRecognizerState.

Answer 2

Have you set userInteractionEnabled on your view that the touches will be inside?