In facebook app, when you scroll your TableView down, an UIView on the top will disappear with animation. How can i do this in code, that is, access and modify the Y position of the UIView depend on the contentoffset of tableview's scrollview
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I don't know if this is possible and I highly doubt that it is but I'm wondering if there's a way where I can prevent a button for example from scrolling in a UIScrollView using Objective-C programming?
Sure. Simply update the button's origin as the scroll view scrolls.
In your view controller, implement the appropriate scroll view delegate method. If not done already, setup your view controller as the scroll view's delegate.
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
CGPoint offset = scrollView.contentOffset;
CGRect frame = self.fixedButton.frame;
frame.origin.y = offset.y + 40;
self.fixedButton.frame = frame;
}
This will keep the self.fixedButton button 40 points below the top of the visible portion of the scroll view. Adjust as needed.
The above all assumes the button is a subview of the scroll view.
Of course it may be a lot easier if the button and the scroll view share a common parent view. Then the button isn't a subview of the scroll view and won't scroll at all.
In storyboard I have a UITableViewController-->UITableView-->UITableViewSecion--> with static cells
in the same UITableView I also have a UIView that holds a background image and UITextView.
A click on a button shows the UIView and set it's frame, which appears OK, but as soon as I click on the UITextView or make it firstResponder programmatically the keyboard appears and the view disappears
the code when clicking the button
self.myView.frame = CGRectMake(0, self.tableView.contentOffset.y+100, self.tableView.frame.size.width, self.tableView.frame.size.height-100);
self.myView.hidden = NO;
how can I fix this?
Can you copy paste us the code where you add the view to the tableview? Are you doing it with constraints or with frames?
The issue you are having is probably due to the fact the UITableViewControllers automatically shrink the contentSize of the UITableView they hold when the keyboard shows. If you add a UIView to your tableView with addSubview: programmatically, you might need to add a flexible bottom resize mask to make sure when the contentSize shrinks in height, your view stays attached to the top and not the bottom.
Try this on viewDidLoad:
[theViewYouAddedToTableView setAutoresizingMask:UIViewAutoresizingFlexibleBottomMargin];
I'm adding an UIImageView to my custom UITableViewCell. This image is then displayed outside the bounds of the cell. I've also added a UITapGestureRecognizer to the image so that when I tap on the image it will be removed from the view.
However when I tap on the image there is another cell beneath it that instead reacts on the tap. So it seems that adding a tap gesture recognizer to the image doesn't have any effect. And yes I have set userInteractionEnabled to YES for the image.
"This image is then displayed outside the bounds of the cell." your view will not receive touches outside it's bounds therefore the subview will not receive touches if it's parent does not
I have a big problem concerning the resizing of a derived UIView with a UIScrollView as subview.
In the layoutSubviews message I set the frame of the UIScrollView subview. the UIScrollView contains a UIImageView with a big image which can be moved/pinched and so on. The initial contenSize of the UIScrollView is the initial image size.
So far, so good. Moving and pinching of the image works well. Now I have to change the UIView frame (in my app to maximize the UIView). im doing that in a animation block (beginAnimations/commitAnimations). So I set the new frame (which will update the width & height) an then I call [myView layoutIfNeeded] to force the UIScrollView to update its frame in the layoutSubviews message of my view.
The UIView animates correct to its new frame and if the contentOffset of the UIScrollView is currently x 0, y 0 the UIScrollView frame will be updated properly. but here's my problem: if the contentOffset of the UIScrollView is bigger than x 0, y 0 the UIScrollView will "slide in" from upper left to its final position.
I want that the UIScrollView resizes its frame properly with the parents frame and aligns the content (in my case the UIImageView) right. But how could I achieve that?
after hours of web research i found the solution for this problem:
[UIView setAnimationBeginsFromCurrentState: YES];
this will animate all layers from the current state.
I want to make a View with three subviews stacked on top of each other with the middle subview scrollable with the others fixed.
How can I achieve this programmatically? I have tried
to set the contentsize of the root view to the size of the scrollable view but that makes all the views scroll.
-set the contentsize of the middle subview without setting any property for the root view but that makes all the views unscrollable.
Please help. I am new to iOS.
Thanks in advance
You can use the scrollViewDidScroll: delegate callback on the UIScrollView to adjust your view's position. In the callback, get the contentOffset of the scrollview and use that to set your fixed view's position.
For example, if you want your fixed view to always remain 100 px from the top of the scrollview, set its initial frame to (0, 100, width, height), and then in the callback set the frame to (0, contentOffset.y + 100, width, height).
The result is that the subview will appear fixed at a given height.
If your UIScrollView has a superview (i.e. a container view), you can add your 'fixed' view as a subview of the superview instead of the UIScrollView. You'll only have to calculate your frame coordinates once.
You can do it moving sub view from UIScrollView to super view of scrollview like:
Place/set your button over scroll view (not inside scroll view) as shown here in this snapshot. And also set button constraints (position) with respect to super view of your scrollview.
Here is ref. snapshot of hierarchy of position of each view over each-other.