Seems simple, but I can't get this to work with all the different methods I try.
All I want to do, is fade in an image from a black background when I open a new view controller.
So far I've tried this:
//I've set the image alpha to 0 on the storyboard already
- (void)viewDidLoad
{
[UIView animateWithDuration:5.0
delay:0
options: UIViewAnimationOptionCurveEaseIn
animations:^{
myImage.alpha = 1;
}
completion:^(BOOL finished){
NSLog(#"Done!");
}];
}
It runs, and the image comes up immediately (just doesn't seem to be animating!)
I know this is a simple question but I have already spent hours looking for a solution.
If anyone could help it would be much appreciated!
Thanks!
Animation should work from within -viewDidLoad but you may be doing something more in -viewDidLoad that is disrupting the animation.
or...
You could instead move your animation code to -viewDidAppear:
-(void)viewDidAppear:(BOOL)animated
{
//do the animation here
}
Related
I have the following code to animation some view in my app:
void (^animate)() = ^() {
CGRect leftFrame = centerFrame;
leftFrame.origin.x -= centerFrame.size.width;
newViewController.view.frame = centerFrame;
oldViewController.view.frame = leftFrame;
};
if (animated) {
[UIView animateWithDuration:0.3f
delay:0.0f
options:nil
animations:animate
completion:^(BOOL finished){}];
} else {
animate();
}
This animates correctly on iOS 6, however on iOS 7 there is no animation. Oddly the code inside the block does get called and the view does update, just without the animation duration taken into account.
Is there a reason why this block isn't getting called?
I had the same issue: an animation block that works like a charm in iOS6 is executed without the animation in iOS7.
Not sure if this might help you but I moved the animation trigger to viewDidAppear: and now its being animated.
So for you this might look like this:
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
animate();
// do your other stuff here...
}
Your animation may be colliding with another competing animation block, perhaps one called by UIKit during a transition. Instead of passing nil to the animation options, use:
UIViewAnimationOptionOverrideInheritedOptions | UIViewAnimationOptionBeginFromCurrentState
and see if this helps.
I had exactly the same regression between iOS6 and iOS7.
In my case, it was due to the fact that animateWithDuration: was called before the UIView it animates appeared on screen.
In iOS7 it appears that you shouldn't call animateWithDuration: before -(void)viewDidAppear:(BOOL)animated is called on the controlling UIViewController.
I was having the same issue. What it turned out for me is I needed to reference a different part of the UITableViewCell I was animating than I did with iOS 6. It might be a similar issue for you.
It is probably autolayout in iOS 7 which is giving you troubles. I just had the same problem. Instead of animating the frame, you need to animate the constraints.
See Are NSLayoutConstraints animatable? for how to do it.
try using :
[UIView setAnimationsEnabled:YES];
I have to give a delete thumbnail animation in my ipad application just like iphone/ipad applications delete effect.
Any body help me please sample photo is attached
If you need more details then kindly mention it in comments
I have done this using CGAffineTransformMakeRotation. Don't know there is some other better method. But What I have done is my logic you can copy that as it is and you just need to add a delete button on the left top of that view. In the following code I am just animating the thumbnail or any view just like iPad does on its home screen. One thing, You need to declare int direction globally. and every time when you will call this method you will set direction = 1;
-(void)shakeToDelete:(UIView *)shakeMe
{
[UIView animateWithDuration:0.1 animations:^
{
shakeMe.transform = CGAffineTransformMakeRotation(0.05 * direction);
}
completion:^(BOOL finished)
{
direction = direction * -1;
[self shakeToDelete:shakeMe];
}];
}
/// edit
I tried this way and got it working in my sample screen as attached in photo
You better should use an autoreverse and looped animation, cause creating animations over and over will fulfill the phone memory.
With this code, only one animation is retained.
view.transform = CGAffineTransformMakeRotation(-kDeleteAnimationAmplitude);
[UIView animateWithDuration:0.1 delay:0 options:UIViewAnimationOptionRepeat|UIViewAnimationOptionAutoreverse animations:^{
view.transform = CGAffineTransformMakeRotation(kDeleteAnimationAmplitude);
} completion:nil];
Then if you want to stop your animation, just call:
[view.layer removeAllAnimations];
[UIView transitionWithView:imageView
duration:3.0
options:UIViewAnimationOptionTransitionCrossDissolve
animations:^{
imageView.image = [UIImage imageNamed:[welcomePhoto objectAtIndex:photoCount]];
}
completion:^(BOOL finish){
}];
When the animation transition at the three second,
imageView can't receive custom gesture,
other times is fine.
How can i fix it? Thanks.
The reason : when UIView animation starts from one point to another, the actual view goes to the new position straight away but it is just hidden. And the view you see moving is just an illusion.
My Given reason is based on paul hagerty's stanford lecture about animation.
The solution to this can be found in other given answer.
I use a UIView animation to randomly animate 5 squares (UIButtons) around the screen. Depending on a user selection, there are anywhere from 2 to 5 squares visible. When only 2 are visible, the other three's hidden values get set to YES, so they are actually still animating (right?), they just aren't visible. But when only 2 are visible, the animation is smooth, but when all five are visible, the animation gets choppy. I'm not really sure how to describe it, because the squares are still moving at the correct speed and moving to the correct points; the choppiness isn't terrible, just bad enough to be noticeable. Is there any way to get rid of it? This is the code I use to animate the squares:
Edit: changed animations to block:
[UIView animateWithDuration:animationSpeed
delay:0
options:UIViewAnimationOptionCurveLinear
animations:^{
view.center = destPoint;
}
completion:^(BOOL finished){
if([view isEqual:squareThree])
[self moveBadGuys];
}
];
/*for(UIButton* button in squareArray) {
if(!shouldMove)
return;
[UIView beginAnimations:#"b" context:nil];
[UIView setAnimationDuration:animationSpeed];
[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
view.center = destPoint;
[UIView commitAnimations];
}*/
Edit: the view presenting this is the third in a stack of three UIViewController presented with
ViewController* controller = [[[ViewController alloc] init] autorelease];
[self presentModalViewController:controller animated:NO];
Does this way of presenting views eat up memory?
There are a few things that can cause this. It always comes down to how complex the content is. Also, simulator can be really bad about handling animation, so be sure you are testing on real hardware.
Are there large images on the buttons? Are the buttons casting shadows? Those things can slow it down.
Also- use block based animation. Not the old begin-commit methods.
Not exactly sure why it's slow, but have you tried nesting the thing differently?
if(!shouldMove)
return;
[UIView beginAnimations:#"b" context:nil];
[UIView setAnimationDuration:animationSpeed];
[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
for(UIButton* button in squareArray) {
view.center = destPoint;
}
[UIView commitAnimations];
does (almost - the logic is a bit different in the !shouldMove case, but that's a different story) the same, but in a cleaner way.
I want my text box to blink (like the old LCD clocks).
Right now, I'm calling a myriad of NSTimers and selectors that wait, change the alpha, wait, then change it back. Even with this, it looks really bad, and I'm thinking I have to put an NSTimer to gradually change the alpha, but from what I hear they are not meant for things of that precision.
My thoughts are there must be a way to do this a lot better than how I am currently implementing it. It feels like hack.
Using an animation delegate might make it less "hacky":
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDelegate:self];
[UIView setAnimationDidStopSelector:#selector(animationDidStop:finished:context:)];
[myLabel setAlpha:0.0];
[UIView commitAnimations];
And then you can have your didStopSelector restart the animation:
- (void)animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context {
[self displayLabel];
}
Depending on the animationID, you could take different actions, etc. Using UIView's setAnimationDelay might come in handy as well.
UIView also has a setDuration call for animations:
[UIView setAnimationDuration:0.1];
If you are building for iOS4, check the documentation since you should be using block-based animation calls rather than these delegate based ones.
you can set the alpha of the lable with annimation just like
to hide lable with animation
[UIView animateWithDuration:0.2 delay:0.1 options:UIViewAnimationOptionCurveEaseOut animations:^{
lblDistance.alpha=0;
} completion:^(BOOL finished) {
if (finished) {
}
}];
to show lable with animation
[UIView animateWithDuration:0.2 delay:0.1 options:UIViewAnimationOptionCurveEaseOut animations:^{
lblDistance.alpha=1;
} completion:^(BOOL finished) {
if (finished) {
}
}];
this is the best way anyone can animate and create a blinking lable........
I would use an NSTimer, but instead of messing with alpha channels i would either not draw the text (if that's even possible with Apple's very attribute-limited SDK), or if that's not possible you could always draw something on top of it (like a rectangle).
Using this approach of drawing something over your text would yield better performance.
Though some (okay most) would consider this a ugly hack, let me just say this, "If it looks right, it is right."
NSTimers and changing the alpha is a perfectly acceptable way of doing it - that's certainly what I do. If you are having problems, perhaps a code sample might help us see where the issue is?