iOS dynamic object creation and storage - ios

Question

What I have is a UIButton. What I want to do is, every time the button is clicked, a new UIImageView is created (I will set the size/image etc... in a method) and the UIImageView falls to the bottom of the screen. How do I do this? I've tried creating the object and storing it in an NSMutableArray and doing a for loop on the array but that doesn't seem to work. (example of what I'm doing)
-(IBAction) button {
[self createUiImage];
}
-(void) createUiImage {
UIIMageView *iv = [[UIImageView alloc] initWithFrame:CGRectMake(50, 50, 15, 3)]
iv.image = [UIImage imageNamed:#"image.png"];
iv.hidden = NO;
[self.view addSubview:iv];
[array1 addObject:iv];
}
-(void) dropImageDown {
for (UIImageView *a in array1) {
a.center = CGPointMake(a.center.x, a.center.y + 10);
if (a.center.y > 500) {
[array1 removeAllObjects];
[a removeFromSuperview];
}
}
}
and this dropImageDown method is being controlled by an NSTimer.
forgot to add this: The problem is that the shape isn't falling to the bottom, it appears and doesn't move!
I've also tried a for (int i = 0; i < array size; i ++) but thats not working either
Appreciate the help, thanks

Answer 1

Don't try to use a timer and move the view in steps yourself. It will give jerky animation that puts a large burden on the CPU.
Use UIView animation instead.
Something like this:
-(void) animateImagesDown {
for (UIImageView *a in array1)
{
[UIView animateWithDuration: 1.0
animations: ^
{
a.center = CGPointMake(a.center.x, 500);
}
completion: ^(BOOL finished)
{
[a removeFromSuperview];
}
];
}
}
That code would animate all the view to a center position of 500, then remove them. (They would all be animated at the same time.)
UIView animations use ease-in, ease-out animation by default. There are other variations on the animateWithDuration UIView animation methods that let you control the animation timing. (look at the docs on the methodanimateWithDuration:delay:options:animations:completion:(Specifically the options parameter.)

Answer 2

https://developer.apple.com/library/ios/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/WorkingwithObjects/WorkingwithObjects.html use this link which can be help to understand the concept

Answer 3

Found the reason I was having issues... I was not initializing the NSMutableArray therefore it wasn't being recognized.