I am using an array to try to load images into specific UIImageViews. I have 10 UIImageViews set up on my storyboard.
I also have a Game Over method that runs whenever the frame of one UIImageView intersects with another UIImageView. For some reason, whenever I try to use the array to load my UIImageViews, my Game Over method immediately triggers. I can't figure out why. As soon as I remove the initWithImage line, the game runs normally. Any ideas?
- (void)viewDidLoad
{
KanaCharacters = [[NSArray alloc] initWithObjects:[UIImage imageNamed:#"a.png"],...
nil];
int imageDisplay = arc4random_uniform([KanaCharacters count]);
Monster1 = [[UIImageView alloc] initWithImage:[KanaCharacters objectAtIndex:imageDisplay]];
}
-(void) Collision
{
if ((CGRectIntersectsRect(Monster1.frame, Ship.frame)) && (Monster1Hit==NO))
{
[self GameOver];
}
}
-(void)GameOver
{
WinOrLose.hidden=NO;
WinOrLose.text = [NSString stringWithFormat:#"You Lose!"];
}
I suspect that Collision if firing once an image in Monster1 and Ship.frame.
This is because I suspect your Monster is being placed where your ship is?
you may want to move the ship or the monster before you add the image into the view.
Related
My first post to the forums but I have been using answers posted here for the last several months and find the answers incredibly useful! I'm still learning objective c and still learning some basics.
My code is several hundred lines right so I don't want to the post the whole code. The basic premise of the code is to load a series of random images to random locations on the screen.
When I was trying to figure out how to deal with this idea I made a simple test version that would add one balloon when a button is pressed and then when you hit pop balloons delete all the balloon images that were created.
This balloon code worked just fine, and then I added this same concept into my main code. However now when I use it only a larger scale the code would freeze at 99% cpu usage and 18.5 MB memory. The code never failed but would sit frozen. The larger version is basically just adding multiple balloons when a button is pressed instead of one. Sometimes as many as 15 images.
Is there any reason a code of this style would not work on a larger scale? Or how do you go about problem solving an issue when the code freezes and no error is given.
.h file
#interface ViewController : UIViewController
{
// Holds an array of images of the balloons
NSMutableArray *BalloonArray;
// Holds an array file names of the balloon PNG files
NSMutableArray *BalloonNames;
}
-(void)AddBalloon:(id)sender;
-(void)PopBalloons:(id)sender;
#end
.m file
#interface ViewController ()
#end
#implementation ViewController
-(void)viewDidLoad
{
// Allocates memory for the array
BalloonArray = [[NSMutableArray alloc] init];
// Allocates memory and inputs the names of the images
BalloonNames = [NSMutableArray arrayWithObjects:[UIImage imageNamed:#"pink.png"],[UIImage imageNamed:#"blue.png"],[UIImage imageNamed:#"green.png"], nil];
[super viewDidLoad];
}
-(void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
-(void)AddBalloon:(id)sender
{
int x; // x position of the balloon image created
int y; // y position of the balloon image created
int i; // Random index value to pull a random balloon image out
// Random number generator for the x and y position
x = arc4random_uniform(230) + 30;
y = arc4random_uniform(400) + 150;
// Random index value from 0 to 2
// Random based on how many images there are to chose from
i = arc4random_uniform(3);
// Uses the image from the index value previously randomnized
UIImage *Balloon = [BalloonNames objectAtIndex:i];
// Places the UIImage in a UIImageView
UIImageView *BalloonView = [[UIImageView alloc] initWithImage:Balloon];
// Sizes the image to the correct size
BalloonView.frame = CGRectMake(0, 0, 50, 100);
// Centers the image using the x and y coordinates
BalloonView.center = CGPointMake(x,y);
// Adds the image view to the view
[self.view addSubview:BalloonView];
// Adds the image view to the array
[BalloonArray addObject:BalloonView];
}
-(void)PopBalloons:(id)sender
{
// Removes each image in the array out of the main view
for(UIImageView *Test in BalloonArray)
{
[Test removeFromSuperview];
}
// Removes all object from the array
[BalloonArray removeAllObjects];
}
#end
Make the method -(void)AddBalloon:(id)sender to run on a Separate Thread. Perhaps you can use [NSThread detachNewThreadSelector:#selector(myThreadMainMethod:) toTarget:self withObject:nil];. Have a look at Apple Documentation
I'm trying to create horizontal scroll view(s). Each view containing one image. [done]
Initially when app is opened I'd display couple of images i.e 3, so user can scroll back and forth between images. [done]
However I want to be able to go to another view controller and pick another image(s) maybe two for example and display five images in the scroll view instead of displaying 3 initially.
How would one do that? to "re-refresh" the initial scroll view ?
Update
Should I use delegate for this communication between view controllers? or how is this done?
1 main controller, other containing image selection?
This part above and much more explained by article here.(not advertising, I hope it will help someone as well).
Bounty update part 1 :
I think now that I found my way around delegates, I have additional question that I cannot find answer to, all examples I saw were about updating table views.
Bounty part 2 :
If I were to have a scrollview inside my view controller and some nsimages inside scroll view. i.e :
- (void)viewDidLoad {
[super viewDidLoad];
NSMutableArray *images = ...some images array;
for (int i = 0; i < images.count; i++) {
CGRect frame;
frame.origin.x = self.scrollView.frame.size.width * i;
frame.origin.y = 0;
frame.size = self.scrollView.frame.size;
UIImageView *subview = [[UIImageView alloc] initWithFrame:frame];
subview.image = [images objectAtIndex:i];
[self.scrollView addSubview:subview];
}
self.scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width * images.count, self.scrollView.frame.size.height);
}
And let say my view controller implemented some delegate method didAddImage or didRemoveImage.
Meaning that about images array would get updated.
Actual bounty question :
How would one actually "tell" the view controller, O.K now your scrollview has one more image to display, please re-fresh or reload?
If I were to have a table view instead scroll view and was inserting images I'd do it something like this(in my delegate method) :
-(void) mockDelegatetablemethod:(...) ...{
[self.images addObject:image];
NSIndexPath *indexPath =
[NSIndexPath indexPathForRow:[self.images count] - 1
inSection:0];
[self.tableView insertRowsAtIndexPaths:
[NSArray arrayWithObject:indexPath]
withRowAnimation:UITableViewRowAnimationAutomatic];
[self dismissViewControllerAnimated:YES completion:nil];
}
How would one do this to the scrollview?
Bounty update part 3:
This is "simple" case described above, naturally I'd have to support removing images also as well as if one wants to remove all images and add some new.
How would one actually "tell" the view controller, O.K now your
scrollview has one more image to display, please re-fresh or reload?
Well, you would just add the new image as a subview of the scroll view. So something like:
- (void)addImage:(UIImage*)image {
[images addObject:image];
CGRect frame;
frame.origin.x = self.scrollView.frame.size.width * images.count;
frame.origin.y = 0;
frame.size = self.scrollView.frame.size;
UIImageView *subview = [[UIImageView alloc] initWithFrame:frame];
subview.image = image;
[self.scrollView addSubview:subview];
self.scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width * images.count, self.scrollView.frame.size.height);
}
Or you could have a method that goes and "resets" the scroll view by removing all subviews and then re-adds all the images in your images array. Then call this method in viewDidLoad instead of your code there so that you're not duplicating code.
Basically, there's no silver bullet here. You roll your own.
You're going to need make your image scroller a class that you can tell to load up certain images. You'll need a reference to the existing image scroller, pass that pointer into your other "pick more images" controller. Then the "pick more images" controller can tell the image scroller that there is a new list of images.
This is already implemented by Apple in their iOS sample project "PhotoScroller". It has view reuse as well. They even have a WWDC 2010 video on this. I think its advanced scrollview techniques OR designing apps with scrollviews.
Shouldn't be hard to port over to mac
Let's imagine that I have 2 UIScrollViews with different UIImageViews inside. When I trigger an action I would like the contents, parameters etc (besides the location) of the 2nd UIScrollView to be passed onto the 1st UIScrollView.
So, here's the code that I've come up with:
-(void) someAction {
UIScrollView * scroll = [[UIScrollView alloc] init]; // create an intermediary scrollView
scroll = secondScroll; // here I intent to pass the content of secondScroll to scroll
scroll.frame = firstScroll.frame; // here I assign the frame of firstScroll to scroll
so that it doesn't take the frame of secondScroll;
firstScroll =scroll; // and then pass all the contents of scroll to firstScroll;
}
But when I execute that and trigger the action, the firstScroll seems to take the content of secondScroll, but secondScroll seems to be deleted. I need it to stay as is.
Any help?
Thanks
-(void) someAction {
UIScrollView * scroll = [[UIScrollView alloc] init]; // create an intermediary scrollView
That's WRONG. You'll be leaking memory with it, since you're losing the pointer to that scroll view after assigning it to a different object. You'd better simply declare UIScrollView *scroll; for that purpose.
scroll = secondScroll; // here I intent to pass the content of secondScroll to scroll
But that's not what happens. The scroll views don't magically copy themselves; if you assign one to another, you only assign the pointer.
scroll.frame = firstScroll.frame; // here I assign the frame of firstScroll to scroll
// so that it doesn't take the frame of secondScroll;
So, from now on, if you operate on scroll, it will effect secondScroll.
firstScroll = scroll; // and then pass all the contents of scroll to firstScroll;
And with this, you assign firstScroll to SecondScroll. So firstScroll will now essentially be secondScroll, losing it (leaking memory again and again) and having done nothing useful.
}
What on Earth are you trying to do with this?
Assuming you want to exchange the two views, you should do something like this instead:
BOOL firstScrollVisible = NO; // in -init or whatever
- (void) someAction
{
if (fistScrollVisible)
[self.view bringSubviewToFront:secondScroll];
else
[self.view bringSubviewToFront:firstScroll];
firstScrollVisible = !firstScrollVisible;
}
Try doing the following:
- (void)someAction {
[firstScroll removeFromSuperview]; // So that we do not leave the old firstScroll as a subview
firstScroll = [secondScroll copy]; // Makes a copy of secondScroll and stores it in firstScroll
[self addSubview:firstScroll]; // Add the new firstScroll to the view
}
Important Note(s):
This code will leak memory, as -copy returns an object with a reference count of +1, but we do not release firstScroll. I highly suggest you make firstScroll and secondScroll into nonatomic, retain properties (#property (nonatomic, retain) UIScrollView *firstScroll). If you want more info on this, just ask. Furthermore, you will need to make sure that firstScroll and secondScroll are never garbage values when this code gets run (it will crash) - depending on when and how it is called you may be fine.
If you want to clone a UI element, you use NSCoder (just like the nib file loader does).
NSData *scrollViewData = [NSKeyedArchiver archivedDataWithRootObject:self.firstScroll];
CGRect oldFrame = self.secondScroll.frame;
self.secondScroll = [NSKeyedUnarchiver unarchiveObjectWithData:scrollViewData];
self.secondScroll.frame = oldFrame;
This serializes the UIView and all its subviews into an NSData and then creates a complete copy of those from the NSData.
#jrtc27 Thanks for your answer. I think I've found a solution and it seems to accomplish what I'm looking for. But I'm not sure if it's the right way or not. Here's what I do:
- (void)someAction {
[[firstScroll subviews] makeObjectsPerformSelector:#selector(removeFromSuperView:);//here I sort of blank out the content of the firstScroll
NSArray * array = [secondScroll subviews];//place all subview of the secondScroll in array
int i = 0;
int nrOfSubviews = [array count];
for (i=0;i<nrOfSubviews;i++) { //appoint them one by one to firstScroll
[firstScroll addSubview:[array objectAtIndex:i]];
}
}
I wanted to create a gallery. It loads different images based on the category, that a user selects. I used to populate images in UIImageViews.
My when selecting different categories is that it does not clear the previously selected images. This is my code for populating images.
-(void)refresh{
categoryLabel.text = treatment.treatmentName;
NSMutableArray *galleryImages =[NSMutableArray alloc] ;
galleryImages = [[PatientImage alloc]find:treatment.treatmentId];
int imgCount = [galleryImages count];
for(int i=0;i<imgCount;i++){
PatientImage *apatientImage = [galleryImages objectAtIndex:i];
UIImage *img1 = [UIImage imageNamed:apatientImage.imageBefore];
UIImageView *myImageView = [[UIImageView alloc] initWithImage:img1];
myImageView.contentMode = UIViewContentModeTopRight;
myImageView.frame = CGRectMake(120+i*240,120.0,100.0, 100.0);
[self.view addSubview:myImageView];
UIImage *img2 = [UIImage imageNamed:apatientImage.imageAfter];
UIImageView *myImageView2 = [[UIImageView alloc] initWithImage:img2];
myImageView2.contentMode = UIViewContentModeTopRight;
myImageView2.frame = CGRectMake(120+i*240+300,120.0,100.0, 100.0);
[self.view addSubview:myImageView2];
}
}
First things first, You have some memory leaks there. You are allocating UIImageViews but are not releasing them anywhere, after you have added them to your view. I don't know if that applies to ARC, though. Same applies to your Mutable array, but I suppose you are releasing it after the 'for' loop somewhere, since it seems you posted code after omitting some of it.
As far as your actual question is concerned, I wouldn't do this this way. I would make the mutable array an object variable, and then fill it with my image views. When calling refresh again, I would first call -removeFromSuperview on each image view, then empty the array, then repopulate it and add the new subviews to my view. That is the simple way.
I don't know if you are using ARC, but you should be careful about memory management when using dynamically loaded views. Each time you add a view to another one, you increase its retain counter. You must then call release to remove ownership, and let the iOS runtime handle the rest.
Also note that operations such as this using views are expensive in terms of memory. So, another way of repopulating the gallery view is to just change the image an imageView holds. That will save you some memory, and time. In case the view doesn't have a constant number of images to be displayed, you can refine your algorithm to change the images on the already created image views, and then add more image views if necessary or delete the remaining ones, if any.
I hope I helped.
try at the start of refresh call
[[self subviews] makeObjectsPerformSelector: #selector(removeFromSuperview)];
or
for (id imageView in self.subviews){
if([imageView isKindOfClass:[UIImageView class]]) [imageView removeFromSuperview];
}
call [tableview reloadData] if You are using tableview to show your gallery images
or call view's
[self.view setNeedsDisplay] method for refreshing the view.
Okay so what I want to do is I have an app with many uiimageviews that you can move and do actions with them. Instead of creating many outlets for each, how can i create one variable that refers to all these outlets (not IBOutletCollection because i would have to use array and arrays dont have properties that uiimageviews do. Ive tried that if youre positive it works please show me the code). For example I have many uiimageviews, variable = all my uiimageviews
So then [variable move]; it moves all the uiimageviews. (NOT BITWISE & or && OPERATOR)
How about creating all of the UIImageView instances and wrapping them in a single transparent UIView. Then when you want to move all the UIImageViews you'd just need to move their wrapper (said UIView).
update
UIView *wrapper = [[UIView alloc] initWithFrame:bigFrame];
for (size_t i = 0; i<10; i++) {
UIImageView *iv = [[UIImageView alloc] initWithImage:someUIImage];
[wrapper addSubview:iv];
[iv release];
}
[self.view addSubview:wrapper];
[wrapper release];
This code creates an uiview that has 10 uiimageviews inside it. When you move that view (wrapper view) the child image views will move with it.