I'm moving a UIView up with a swipe, but I want the imageView within the UIView to stay in its position. I got this working by placing my imageView under a separate UIView ( I needed to include a label under the imageview) by doing [self.view insertSubview:self.imageViewHolder aboveSubview:self.panedView];. The problem now is that when i swipe down over the imageView, my view that I swiped up won't come back down unless I swipe around the imageView. This is because the UIGestureRecognizer is associated with the view under the imageView. Any simple ways around this?
Gesture recognizer code:
UISwipeGestureRecognizer * swipeUpRec = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(handleUpSwipe:)];
[self.panedView addGestureRecognizer:swipeUpRec];
[self.imageViewHolder addGestureRecognizer:swipeUpRec];
I have a ViewController on which I can move multiple UIImageViews using gesture recognizers. it's working fine but the UIImageView selected is not on top of the others.
The UIImageViews keep the order of their creation so the last ones are always bellow the first ones.
Any advice?
When you've selected your new UIImageView - from your UIViewController you should call:
[self.view bringSubviewToFront:imageView];
That should help.
You can use,
[superView bringSubviewToFront:touchedview]; for bringing the subview to the front
What you need to do it programmatically reorder them . You can do this in the following way
-(void)bringTheDesiredImageViewInFront:(int))_tagForImageView
{
for(UIImageView *_subView in self.view.subviews)
{
if([_subView isKindOfClass:[UIImageView class]])
{
UIImageView *temp=(UIImageView *)_subView;
if([temp tag]==_tagForImageView)
[self.view bringSubviewToFront:temp];
}
else
continue;
}
}
Call this method whenever the selector for any gestureRecognizer is called on any UIImageView . Also set the different tag values for different UIImageView . The above method could be called like this ,
UIImageView *imageView=[[UIImageView alloc] init];
[imageView setTag:1];
[self bringTheDesiredImageViewInFront:imageView.tag]
It may seem like duplicate, but I can't actually find any good answer to my concrete situation.
I have some button with background image (1pt-wide, streched), icon-like image inside along with the text label. It's height is 33pt, I need to make it's hittest area 44pt-high.
I saw two solutions, but neither of them works for me.
First solution is to enlarge frame and adjust image so it would have some padding. But that is not acceptable for me, because I have both background image and image inside the button.
Second solution is to subclass UIButton (which is absolutely acceptable) and override - (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event. I did that, when I put some breakpoints in this method and tried to tap in desired area nothing happened (breakpoints worked when tapped inside the button frame).
Are there any other solutions? What could be possibly wrong with the second solution?
If you create the view programmatically, you can instantiate a UIView that is 44px high, add a tap gesture recognizer to it, and add your UIButton as a subview inside this view:
CGRect bigFrame = CGRectMake(0,0,100,44);
UIView *big = [[UIView alloc] initWithFrame:bigFrame];
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(doPress)];
[big addGestureRecognizer:tapRecognizer];
UIButton *yourButton = ...
[big addSubview:yourButton];
[self.view addSubview:big];
Then implement the selector as:
- (void)doPress {
[yourButton sendActionsForControlEvents:UIControlEventTouchUpInside];
}
In that way, the outer view taps will be interpreted as button presses for your button.
I have a UIScrollView, created programmatically, inside of a UIView. What do I need to do to ensure that I can use the delegate method scrollViewDidEndDecelerating?
Here's what I have set up, please assume that within the UIScrollView, that there are three UIImageViews. When the page first loads, I am looking at the center UIImageView and I can scroll once backwards or once forwards. The reason why I need this delegate method is because I intend to use it to calculate which UIImageView I am currently looking at.
ViewController.h
#interface ViewController : UIViewController <UIScrollViewDelegate>
ViewController.m
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:self.view.bounds];
scrollView.pagingEnabled = YES;
[self.view addSubview: scrollView];
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
NSLog(#"scrollViewDidEndDecelerating");
}
Add
scrollView.delegate = self
after the scroll view initialization.
In your delegate method, you can test each uiimageview center to see Which one match the uiview center, That's the uiimageview you are looking at.
I have placed an image (UIImageView) on the navigation bar. Now I want to detect the touch event and want to handle the event. How can I do that?
In practical terms, don't do that.
Instead add a button with Custom style (no button graphics unless you specify images) over the UIImageView. Then attach whatever methods you want called to that.
You can use that technique for many cases where you really want some area of the screen to act as a button instead of messing with the Touch stuff.
A UIImageView is derived from a UIView which is derived from UIResponder so it's ready to handle touch events. You'll want to provide the touchesBegan, touchesMoved, and touchesEnded methods and they'll get called if the user taps the image. If all you want is a tap event, it's easier to just use a custom button with the image set as the button image. But if you want finer-grain control over taps, moves, etc. this is the way to go.
You'll also want to look at a few more things:
Override canBecomeFirstResponder and return YES to indicate that the view can become the focus of touch events (the default is NO).
Set the userInteractionEnabled property to YES. The default for UIViews is YES, but for UIImageViews is NO so you have to explicitly turn it on.
If you want to respond to multi-touch events (i.e. pinch, zoom, etc) you'll want to set multipleTouchEnabled to YES.
To add a touch event to a UIImageView, use the following in your .m file:
UITapGestureRecognizer *newTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(myTapMethod)];
[myImageView setUserInteractionEnabled:YES];
[myImageView addGestureRecognizer:newTap];
-(void)myTapMethod{
// Treat image tap
}
You can also add a UIGestureRecognizer. It does not require you to add an additional element in your view hierarchy, but still provides you will all the nicely written code for handling touch events with a fairly simple interface:
UISwipeGestureRecognizer *swipeRight = [[UISwipeGestureRecognizer alloc]
initWithTarget:self action:#selector(handleSwipe:)];
swipeRight.direction = UISwipeGestureRecognizerDirectionRight;
[imgView_ addGestureRecognizer:swipeRight];
[swipeRight release];
UISwipeGestureRecognizer *swipeLeft = [[UISwipeGestureRecognizer alloc]
initWithTarget:self action:#selector(handleSwipe:)];
swipeLeft.direction = UISwipeGestureRecognizerDirectionLeft;
[imgView_ addGestureRecognizer:swipeLeft];
[swipeLeft release];
I've been on different threads on the past few hours trying to find a solution for my problem, to no avail. I see that many developers share this problem, and I think people here know about this. I have multiple images inside a UIScrollView, trying to get tap events on them.
I am not getting any events from an UIImangeView, but I do get an event from a similar UILable with very similar parameters I am setting to it. Under iOS 5.1.
I have already done the following:
set setUserInteractionEnabled to YES for both `UIImageView and parent
view .
set setMultipleTouchEnabled to YES for UIImageView.
Tried subclassing UIImageView, didn't help any.
Attaching some code below, in this code I initialize both a UIImageView and UILabel, the label works fine in terms of firing events. I tried keeping out irrelevant code.
UIImageView *single_view = [[UIImageView alloc]initWithFrame:CGRectMake(200, 200, 100, 100)];
single_view.image = img;
single_view.layer.zPosition = 4;
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(singleTapGestureCaptured:)];
[single_view addGestureRecognizer:singleTap];
[single_view setMultipleTouchEnabled:YES];
[single_view setUserInteractionEnabled:YES];
[self.myScrollView addSubview:single_view];
self.myScrollView.userInteractionEnabled = YES;
UILabel *testLabel = [[UILabel alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
testLabel.backgroundColor = [UIColor redColor];
[self.myScrollView addSubview:testLabel];
[testLabel addGestureRecognizer:singleTap];
[testLabel setMultipleTouchEnabled:YES];
[testLabel setUserInteractionEnabled:YES];
testLabel.layer.zPosition = 4;
And the method which handles the event:
- (void)singleTapGestureCaptured:(UITapGestureRecognizer *)gesture
{
UIView *tappedView = [gesture.view hitTest:[gesture locationInView:gesture.view] withEvent:nil];
NSLog(#"Touch event on view: %#", [tappedView class]);
}
As said, the label tap is received.
Instead of making a touchable UIImageView then placing it on the navbar, you should just create a UIBarButtonItem, which you make out of a UIImageView.
First make the image view:
UIImageView *yourImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"nameOfYourImage.png"]];
Then make the barbutton item out of your image view:
UIBarButtonItem *yourBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:yourImageView];
Then add the bar button item to your navigation bar:
self.navigationItem.rightBarButtonItem = yourBarButtonItem;
Remember that this code goes into the view controller which is inside a navigation controller viewcontroller array. So basically, this "touchable image-looking bar button item" will only appear in the navigation bar when this view controller when it's being shown. When you push another view controller, this navigation bar button item will disappear.
You might want to override the touchesBegan:withEvent: method of the UIView (or subclass) that contains your UIImageView subview.
Within this method, test if any of the UITouch touches fall inside the bounds of the UIImageView instance (let's say it is called imageView).
That is, does the CGPoint element [touch locationInView] intersect with with the CGRect element [imageView bounds]? Look into the function CGRectContainsPoint to run this test.
First, you should place an UIButton and then either you can add a background image for this button, or you need to place an UIImageView over the button.
Or:
You can add the tap gesture to a UIImageView so that get the click action when tap on the UIImageView.
For those of you looking for a Swift 4 solution to this answer, you can use the following to detect a touch event on a UIImageView.
let gestureRecognizer: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(imageViewTapped))
imageView.addGestureRecognizer(gestureRecognizer)
imageView.isUserInteractionEnabled = true
You will then need to define your selector as follows:
#objc func imageViewTapped() {
// Image has been tapped
}
Add gesture on that view. Add an image into that view, and then it would be detecting a gesture on the image too. You could try with the delegate method of the touch event. Then in that case it also might be detecting.