i want draw a wave line with 4500 points when the finger moves,but I don't want to make my view 4500 wide.
In my limited experience , my idea is when the finger moves , increase width of the View and then draw the new increase rectangle use -setNeedsDisplayInRect:
CGRect frame = self.frame;
frame.size.width +=568;
self.frame = frame;
[self setNeedsDisplayInRect:CGRectMake(568* self.currentPage, 0, 568, self.bounds.size.height)];
the result is :
But if i didn't change the frame of the view,it works fine:
For this problem,I am searching for a long time on net. But no use.
What happened when I change the frame Of my view?
Try:
CGRect frame = self.bounds;
instead of CGRect frame = self.frame;
Related
i wonder if u could help out to fix my issue here.
For example i have 2 UIViews inside the UIScrollView, let say the first UIView i've changed the size of its height and at the same time i change the y axis of the second UIView as well through this animation method. here's my code:
[UIView animateWithDuration:0.1f animations:^{
CGRect rect = informationView.frame;
rect.size.height += 100.f;
informationView.frame = rect;
CGRect rectAddView = additionalView.frame;
rectAddView.origin.y += 100.f;
additionalView.frame = rectAddView;
}];
After those have been rendered (the height and Y axis). It works fine. And i changed the content size of that UIscrollview so it can be scroll it down. Here's the problem when i try to scroll down, surprisingly the height of the First UIView and Y axis of the second UIView are back like from the beginning. i don't how & why. So i just need wise explanation if there's somebody could help me here. Thank you
I have created mainView objcet of UIView and added one subview on it. I applied transform on mainView for reducing frame size. But frame of subview of mainView was not reduced. How to reduce the size of this subview.
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
CGFloat widthM=1200.0;
CGFloat heightM=1800.0;
UIView *mainView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, widthM, heightM)];
mainView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"te.png"]];
[self.view addSubview:mainView];
CGFloat yourDesiredWidth = 250.0;
CGFloat yourDesiredHeight = yourDesiredWidth *heightM/widthM;
CGAffineTransform scalingTransform;
scalingTransform = CGAffineTransformMakeScale(yourDesiredWidth/mainView.frame.size.width, yourDesiredHeight/mainView.frame.size.height);
mainView.transform = scalingTransform;
mainView.center = self.view.center;
NSLog(#"mainView:%#",mainView);
UIView *subMainView= [[UIView alloc] initWithFrame:CGRectMake(100, 100, 1000, 1200)];
subMainView.backgroundColor = [UIColor redColor];
[mainView addSubview:subMainView];
NSLog(#"subMainView:%#",subMainView);
}
NSlog of these views:
mainView:<UIView: 0x8878490; frame = (35 62.5; 250 375); transform = [0.208333, 0, 0, 0.208333, 0, 0]; layer = <CALayer: 0x8879140>>
subMainView:<UIView: 0x887b8c0; frame = (100 100; 1000 1200); layer = <CALayer: 0x887c160>>
Here the width of mainView is 250, the width of subview is 1000. but when i get the output in simulator, subview is occupied correctly, but it's not cross the mainView. How it is possible? How to get frame of subview with respect mainView frame after transformation?
What you're seeing is expected behavior. The frame of an UIView is relative to its parent, so it doesn't change when you apply a transformation to its superview. While the view will appear 'distorted' too, the frame won't reflect the changes since it's still at exact the same position relative to its parent.
However, I assume you would like to get the frame of the view relative to the topmost UIView. In that case UIKit offers these functions:
– [UIView convertPoint:toView:]
– [UIView convertPoint:fromView:]
– [UIView convertRect:toView:]
– [UIView convertRect:fromView:]
I applied these to your example:
CGRect frame = [[self view] convertRect:[subMainView frame] fromView:mainView];
NSLog(#"subMainView:%#", NSStringFromCGRect(frame));
And this is the output:
subMainView:{{55.8333, 83.3333}, {208.333, 250}}
In addition to s1m0n answer, the beautiful thing about applying a transform matrix to your view, is that you can keep reasoning in terms of its original coordinate system (in your case, you can handle subMainView using the non-transformed coordinate system, which is why, even though subMainView's frame is bigger than mainView's transformed frame, it still doesn't cross the parent view, as it gets automatically transformed). This means that when you have a transformed parent view (for example rotated and scaled) and you want to add a subview in a particular point relative to this parent view, you don't have to first keep track of the previous transformations in order to do so.
If you really are interested in knowing the subview's frame in terms of the transformed coordinate system, it will be enough to apply the same transformation to the subview's rectangle with:
CGRect transformedFrame = CGRectApplyAffineTransform(subMainView.frame, mainView.transform);
If you then NSLog this CGRect, you will obtain:
Transformed frame: {{20.8333, 20.8333}, {208.333, 250}}
Which, I believe, are the values that you were looking for. I hope this answers your question!
So in layoutSubviews, I'm calling positionTextView to adjust the frame of my UIScrollView subview (a UIImageView), which contains the following code.
CGRect frame = informationTextView.frame;
frame.origin = CGPointMake(self.contentOffset.x, self.contentOffset.y + 414-44);
informationTextView.frame = frame;
overlayView.frame = frame;
So on the simulator, the subview's frame location remains fixed (according to the contentOffset), but when testing on a device, the frame is moving, as if it wasn't taking the contentOffset into account.
Am I missing a difference between the behavior of the simulator and a device?
I have a round image that I want to "squish" vertically so that it looks more like a horizontal line, then expand it back to the original shape. I thought this would work by setting the layer's anchor point to the center and then animating the frame via UIViewAnimation with the height of the frame = 1.
[self.imageToSquish.layer setAnchorPoint:CGPointMake(0.5, 0.5)];
CGRect newFrame = CGRectMake(self.imageToSquish.frame.origin.x, self.imageToSquish.frame.origin.y, self.imageToSquish.frame.size.width, 1 );
[UIView animateWithDuration:3
animations:^{self.imageToSquish.frame = newFrame;}
completion:nil];
But the image shrinks toward the top instead of around the center.
You’re giving it a frame that has its origin—at the top left—in the same position as it started. You probably want to do something more like this, adding half the image’s height:
CGRect newFrame = CGRectMake(self.imageToSquish.frame.origin.x, self.imageToSquish.frame.origin.y + self.imageToSquish.frame.size.height / 2, self.imageToSquish.frame.size.width, 1);
Alternatively—and more efficiently—you could set the image view’s transform property to, say, CGAffineTransformMakeScale(1, 0.01) instead of messing with its frame. That’ll be centered on the middle of the image, and you can easily undo it by setting the transform to CGAffineTransformIdentity.
I'm trying to move and resize a label, but what happens is the label resizes immediately then moves into position. I first tried simply the commented out lbl.frame line. Next I found this question:
How to animate while resizing UIView
And added all the other code except for the contentMode. This did what I wanted, but the Label's font did not adjust downwards as the label shrunk. ( I tick adjust to fit in xib ). Finally adding the contentMode line gave me the same result as my original frame line - shrink immediately first them animate the move.
lbl.contentMode = UIViewContentModeRedraw;
[UIView animateWithDuration:1.0 delay:0.0
options:(UIViewAnimationOptionAllowUserInteraction)
animations:^{
//lbl.frame = CGRectMake(x, mStartingLine.frame.origin.y+mStartingLine.frame.size.height, 100, 100);
CGRect theBounds = lbl.bounds;
CGPoint theCenter = lbl.center;
theBounds.size.height = 100;
theBounds.size.width = 100;
theCenter.y = mStartingLine.frame.origin.y+mStartingLine.frame.size.height+50;
theCenter.x = x;
lbl.bounds = theBounds;
lbl.center = theCenter;
}
completion:nil
];
I suspect that the auto text resizing feature doesn't work with Core Animation.
What I would suggest doing is to set the label to it's final size (using it's bounds) then apply a transform to it that shrinks it back down to it's starting size. The end effect of those things is that it should stay at the same apparent size.
Finally, use animateWithDuration:animations: to set the view's transform back to the identity transform, so it grows to it's new size.
I don't know what drawing artifacts this will cause - you'll have to try it.