I have a big scroll view. I just wish to scroll around the scroll view with fixed steps on every button press. However when I write the following code the scroll view scrolling is very jaggy. Can someone explain why?
CGPoint lstructCurrentPoint = self.objScrollView.contentOffset;
lstructCurrentPoint.x += 400;
[UIView animateWithDuration:1.0f
delay:0.0f
options:UIViewAnimationOptionCurveLinear
animations:^{
[self.objScrollView scrollRectToVisible:CGRectMake(lstructCurrentPoint.x,
lstructCurrentPoint.y,
self.objScrollView.bounds.size.width,
self.objScrollView.bounds.size.height)
animated:NO];
} completion:^(BOOL finished)
{
}];
I do not use the animated:Yes arguement because I need custom scroll speeds between the different contentOffsets.
when you update your scroolview content frame while scrolling with an animation is like you try to update something that is in the past that is already changed... (probably is not the best explanation :D )
try with this in your animation option:
options:UIViewAnimationOptionCurveLinear|UIViewAnimationOptionBeginFromCurrentState
Why don't you just try using
[self.objScrollView scrollRectToVisible:CGRectMake(lstructCurrentPoint.x, lstructCurrentPoint.y,self.objScrollView.bounds.size.width,self.objScrollView.bounds.size.height) animated:YES];
instead of using this within UIView animation function.
Try to use
[self.objScrollView setContentOffset: CGPointMame(lstructCurrentPoint.x, lstructCurrentPoint.y) animated: YES];
instead of scrollRectToVisible.
scrollRectToVisible animated is an animation by itself.
With your current code, you are trying to animate the animation.
Hence it is jerky.
Just use to scroll the rect to visible:
[self.objScrollView scrollRectToVisible:CGRectMake(lstructCurrentPoint.x,lstructCurrentPoint.y,self.objScrollView.bounds.size.width,self.objScrollView.bounds.size.height) animated:YES];
No one can properly answer your question without knowing what content you have in the scrollView.
However, you can find out what is causing this yourself.
Profile the app on your device. This will open Instruments. Select the Core Animation tool.
When the app is running scroll the view so that instruments captures the data.
Now the Time Profiler section will tell you exactly what is taking a long time. Fix this and you'll have smooth scrolling.
Related
I have a UITableView that I'm autoscrolling with setContentOffset. Like so:
CGFloat point = self.table.tblMinutes.contentSize.height - self.table.tblMinutes.bounds.size.height;
[self.table.tblMinutes setContentOffset:CGPointMake(0, point) animated:false];
[self.table.tblMinutes layoutIfNeeded];
[UIView animateWithDuration:20.0 delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
[self.table.tblMinutes setContentOffset:CGPointMake(0, point - 500) animated:false];
} completion:nil];
What I want to achieve is for the scrolling to smoothly slow down and stop. I haven't been able to achieve that.
Calling [self.table.tblMinutes.layer removeAllAnimations] stops the animation, but moves the contentOffset for some reason, not achieving what I want.
I tried using the UIViewAnimationOptionBeginFromCurrentState option in a animation but that did nothing.
Any suggestions?
This is a subset of the classic problem of interrupting an existing animation and replacing it with a different animation.
The problem here is that if you merely remove the existing animation, you will jump to the end of that animation.
The solution to that is to consult the presentation layer and set the layer to that position before removing the existing animation. Now you are starting from midstream and can apply another animation.
Take a look at Kyle Truscott's excellent blog post about this for UIScrollView. UITableView inherits from UIScrollView, so in theory, it should work.
I have a problem that my custom navigation bar appears for the first time with animation. I think it happens because I use auto-layout and it animates it self into the state of landscape or portrait. But I want to have a functionality, that after first time I enter the screen everything is still, and where it belongs. and after that if I turn the screen or if I do something all the animations appears like now.
Is there a good think to omit the first animations when the view creates itself?
The animations are : labels floating from left to right. and 1 label appears as from 0px width and height it scales into 100% width and height
code:
[self.navigationController.navigationBar addSubview:self.topBar];
self.topbar is UIView. I have added it to block [UIView performWithoutAnimation:^{ }]; but it does not helps, everytime the view appears for the first time I have my labels floating from left to right.
The answer is that I used some methods [self layoutIfNeeded]; After setting the constraint. The solution is to have a method set like this:
- (void) yourAnimation:(BOOL)animated{
if(animated){
[UIView animateWithDuration:0.3 animations:^{
//your animated code
//[self layoutIfNeeded];
}];
}else{
[UIView performWithoutAnimation:^{
//your stuff without animation
}];
}
}
I am trying to create a sliding menu (like the one in google maps app) in which menu screen should be shown or added as subview over the existing screen on tapping a button. While showing it, the sub view should be animated from left to right. I tried to animate while adding it as subview, but failed in doing so. Can any one suggest how to do it? (or) Can I do it using navigation controller?
Thanks in advance!!
You need to add the subview, and set it's frame out of the screen.(320,0,100,568 for example).
Of course it's better to use auto layout for that.
Add as subview:
[self.view addSubView:sideMenu];
When you want to show it, just change it's frame using animation block.
[UIView animateWithDuration:0.2 delay:0.1 options:UIViewAnimationOptionCurveEaseInOut animations:^{
sideMenu.frame = CGRectMake(220,0,100,568);
} completion:^(BOOL finished) {
}];
As I said, it's better to use auto layout and not setting frames. I did it only for the example.
I have made a "pull-to-refresh" and when finished updating the inset is removed using animation block. However I'm getting unwanted animations in the custom uitableviewcell, see movie:
https://www.youtube.com/watch?v=rZcEBm_fTUc&feature=youtu.be
Watch carefully at the bottom. I found this:
How can I exclude a piece of code inside a core animation block from being animated?
But don't know how to use it, here is the code that I'm using:
id animation = ^{
//Remove the contentinset
[self.tableView setContentInset:refreshView.initialInset];
};
[UIView animateWithDuration:0.5
delay:0
options:UIViewAnimationOptionAllowUserInteraction |UIViewAnimationOptionBeginFromCurrentState
animations:animation
completion:nil];
[refreshView endAnimation];
}
Thankful for any help on this matter!
I was not reusing my UITableViewCells correctly. Before i removed all subviews from the cell and added them again, which is the wrong way to do it.
By using "reuseIdentifier" for my different UITableViewCells and only instantiating the UILabels and UIButtons once the problem disappeared (along with a lot of other problems)
I have a UITableView in an iPad, and its right half side is covered with a view.
What I want is: when the user scroll the UITableView, I want the covering view to slide (with an animation) to the right until its origin.x is at the end of the right side of the table, so the UITableView is clear to see (just like in the Twitter app for iPad).
The problem is: You can scroll the UITableView and animate a view at the same time. When I start scrolling, I use didStartDraging and even DidScroll to create a [UIView animate...] method, but this method stuck my scrolling.
I tired with block animation. I tried with Gestures. I tried with CABasicAnimation, and it goes quite OK, but somehow all the UISubview "Touch area" in my sliding view stay at the old place (what I mean is that the view gets its new frame, but I can scroll a UIScrollView, which is a UISubview of my view, even when my finger is out of the superviews frame S-:, even that there is no view at that point on screen.)
Any thoughts how can I make the animation without damaging the scroll of the table? (and I heard about the timer in the K and the runloop common modes. Not so helping)
Thanks.
scrollview Delegate methods will be invoked for tableView also ............
you can use following code it worked for me and hope will work for you also.......
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
[UIView animateWithDuration:0.3 animations:^{
[scrollView setFrame:CGRectMake(50, scrollView.frame.origin.y, scrollView.frame.size.width, scrollView.frame.size.height)];
}];
}
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
[UIView animateWithDuration:0.3 animations:^{
[scrollView setFrame:CGRectMake(100, scrollView.frame.origin.y, scrollView.frame.size.width, scrollView.frame.size.height)];
}];
}
set x position of scrollView(tableView) as your requirement......
Have a happy coding....