i am adding two labels and two image view to subview.
when ever i tap on the button i add this subview to mainview.
I am getting images from the web server and save it in local simulator documents.
NSMutableString *about_name_str = [[NSMutableString alloc]init];
[about_name_str appendString:[myDictionary objectForKey:#"firstname"]];
[about_name_str appendString:#" "];
[about_name_str appendString:[myDictionary objectForKey:#"lastname"]];
[about_name_label setText:about_name_str];
NSMutableString *about_addr_str = [[NSMutableString alloc]init];
[about_addr_str appendString:[myDictionary objectForKey:#"state"]];
[about_addr_str appendString:#","];
[about_addr_str appendString:[myDictionary objectForKey:#"country"]];
[about_addr_label setText:about_addr_str];
about_image.image = [UIImage imageWithContentsOfFile:imagepath];
about_logo.image = [UIImage imageWithContentsOfFile:logopath];
if ([myDictionary objectForKey:#"companyurl"]) {
[about_url_button setTitle:[myDictionary objectForKey:#"companyurl"] forState:UIControlStateNormal];
about_url_button.userInteractionEnabled = YES;
}
else {
about_url_button.userInteractionEnabled = NO;
}
[self.view addSubview:about_view];
this my code.
some times i got Program received signal: "EXC_BAD_ACCESS". and application quits.
i check by placing break points,and in debugger i did n't get where i am getting error.
can any one please help me,How can i resolve this.
Thank u in advance.
Try to use NSZombie.. It is a easy way to find where the EXCBADACCESS occurs...
It will specify which Method where and Which object gets deallocated(Its pretty awesome concept i like in Instruments)...
See this Link
http://www.markj.net/iphone-memory-debug-nszombie/
You should insert a breakpoint before this code is executed then step through it to find the exact line which is causing the bad access. You probably have a null or wild pointer somewhere.
Related
This is my code in my application,
[imageview setAlpha:1.0f];
[imageview setImage:[UIImage imageNamed:[NSString stringWithFormat:#"%#.png",[pages objectAtIndex:swipeCount]]]];
[imageview setFrame:CGRectMake(-300, 0, 1368, 1000)];
Edit:
pages = [[NSArray alloc] initWithObjects:#"page1",#"page2",#"page3",#"page4",#"page5",#"page6",#"page7b",#"page8",#"page9",#"page10a",#"page11",#"page12",#"page13b",#"page14",#"page15",#"page16a",#"page17",#"page18",#"page19",#"page20",#"page21",#"page22",#"page23",#"page24",#"page25", nil];
imageview=[[UIImageView alloc]init];
its working properly, problems except when the app enters background and comes back to foreground shows the following error,
*** -[UIImage isKindOfClass:]: message sent to deallocated instance 0x1e8b10
What wrong with the code?
Please help me out
Yes, you need to allocate memory to your UIImage. What is basically happening is that your image is being temporarily stored in the memory and deallocated upon closing the app so iOS could allocate that memory to more immediate needs. You can fix that as below. I'm also gonna allocate a string since stringWithFormat returns an autorelease String.
NSString *imageName = [[NSString alloc] initWithFormat::#"%#.png",[pages objectAtIndex:swipeCount]];
UIImage *myImage = [UIImage imageNamed:myImage];
[imageview setImage:image];
Try using properties. Make array,imageView as a property and then use
self.pages and self.imageView
see this good article on properties
Objective-c properties
I have face strange problem on UIButton.
When i tap button the app is crash .
I wrote below code for that...
-(IBAction)renameTest:(id)sender
{
NSLog(#"Tapped");
// UIButton *button = (UIButton *)sender;
NSUInteger row = 1;//button.tag;
NSString * titlename = [titleArray objectAtIndex:row];
RenameTest *renameVC = [[RenameTest alloc]initWithNibName:#"RenameTest" bundle:nil];
renameVC.titlespell = titlename;
NSLog(#"titlespell = %#",renameVC.titlespell);
NSLog(#"title = %#",titlename);
// [button release];
[self.navigationController pushViewController:renameVC animated:YES]; //here APP is cresh
[renameVC release];
}
I check also my .Xib file name .It is ok and files are there.
error msg is below :
2012-07-11 14:28:29.079 TestApp[238:207] -[__NSCFDictionary _isNaturallyRTL]: unrecognized selector sent to instance 0x73d8a80
Thanks in Advance.
[button release] is causing the problem. Remove it and check.
_isNaturallyRTL is an NSString method (private), and it looks like you are passing a dictionary instead of a string somewhere.
Breaking on the exception and showing us the call stack at that point would help tremendously.
If u have created the button in xib file then u cannot release it because you have not allocated it and claimed ownership.. U should call release only on objects you have allocated by calling alloc..
Remove the [button release] statement .. that should fix the crash!
You have a crash which is related to a dictionary and your titlename string is set equal to, titleArray objectAtIndex:row. I believe, without seeing the declaration of your variables, that titleArray is a dictionary, or is a NSMutableArray importing from a plist of dictionaries, either way you need to use objectForKey, when using dictionaries, like this:
[[titleArray objectAtIndex:(NSUInteger *)] objectForKey:(NSString *)]
Obviously replace (NSUInteger *) with your integer row and (NSString *) with the name of your key. This may not be the answer but from your crash report and visible code, this is what I assume.
Happy November to all,
Well I tried Xcode Build and analyze on my project, and it showed some unusual leaks, which I couldn't quite accept with my knowledge of Objective C.
So I decided to put up a test project and ask here..
MemoryTestController.h
#interface MemoryTestController : UIViewController{
UIImageView *tstImageView;
}
#property(nonatomic,retain) UIImageView *tstImageView;
#end
MemoryTestController.m
#implementation MemoryTestController
#synthesize tstImageView;
- (void)viewDidLoad{
[super viewDidLoad];
self.tstImageView = [[UIImageView alloc] //<==This object is leaking
initWithFrame:<SomeFrame>];
self.tstImageView.image = [UIImage imageNamed:#"SomeImage.png"];
[self.view addSubview:tstImageView];
[tstImageView release];
}
-(void)dealloc{
[tstImageView release];
[super dealloc];
}
#end
When I try Build and analyze, clang static analyzer say
Potential leak of an object at line xx
And the culprit line is
self.tstImageView = [[UIImageView alloc]initWithFrame:<SomeFrame>];
I think I am releasing once for every time I am allocing/retaining. Am I missing something, or Static analyzer has some bugs?
EDIT : Is there any leak there?
Well I run the above project using Leak tool in instrument..It didn't show any leak even though I tried many times..Whom should I believe? Static analyzer or Leak instrument?
your problem is how you release it:
- (void)viewDidLoad{
[super viewDidLoad];
self.tstImageView = [[UIImageView alloc] //<==This object is leaking
initWithFrame:<SomeFrame>];
self.tstImageView.image = [UIImage imageNamed:#"SomeImage.png"];
[self.view addSubview:tstImageView];
[tstImageView release]; // << here
}
you should do it this way:
- (void)viewDidLoad{
[super viewDidLoad];
UIImageView * imageView = [[UIImageView alloc] initWithFrame:<SomeFrame>];
imageView.image = [UIImage imageNamed:#"SomeImage.png"];
self.tstImageView = imageView;
[imageView release];
[self.view addSubview:self.tstImageView];
}
The checker is correct because it cannot assume that the variable is identical to the one you set. Therefore, the form you use in the OP could introduce a reference count imbalance because the ivar's value may not be what you assigned to it by the time you message release upon the ivar.
These cases are not likely for a UIImageView, and quite unlikely in the context of your program, but these examples should give you an idea as to why the checker assumes that object->ivar associations shall not be trusted:
Between creation of the image view and the message to release it via the ivar, you have:
self.tstImageView = [[UIImageView alloc] initWithFrame:<SomeFrame>];
self.tstImageView.image = [UIImage imageNamed:#"SomeImage.png"];
[self.view addSubview:tstImageView];
1) assignment of the image view via the setter
2) access of the image view via the getter
3) direct access of the ivar, when adding to self.view
the setter may have taken a copied or used a cached value. UIImageView is a bad example, but the checker does not know how types are generally passed around - even if it did, it would (at times) make unsafe assumptions.
the simplest example would be:
- (void)setName:(NSString *)inName {
NSString * prev = name;
if (inName == prev) return;
if (0 == [inName count]) name = #"";
else name = [inName copy];
[prev release];
}
the value held by the ivar could change in the meantime. not likely an issue in this case, but let's say that adding the image view as the subview could end up calling back and altering self in the process/effect of adding the subview, and replacing or removing the image view you passed. In that case, the variable view you passed would leak and the view it replaced it with would have a negative imbalance.
Neither of those are likely to happen in your example, but it does happen in real world programs, and the checker is correctly evaluating based on locality, not property (the checker can't assume much of what happens inside a method call). It also encourages one good idiomatic style in this case.
EDIT : Is there any leak there?
Well I run the above project using
Leak tool in instrument..It didn't shown any leak even though I tried
it many times..Whom should I believe? Static analyzer or Leak
instrument?
The static analyzer says there is a potential leak because it is unable to guarantee the reference/allocation it follows is correctly retained/released. You can guarantee that reference counting is correct and please the static analyzer by changing you program to look like I wrote it in my example.
The way you have written it has made it impossible for the analyzer to follow the reference.
If you have no leaks and no zombies, then there is not a leak. But the solution is easy to fix - and programs have a way of changing during development. It's much easier to use the form I posted so it is easier for the toolset and for you to verify the program is correct. The static analyzer is not always correct, but you should adjust your programs to please it because static analysis is very useful. The program I posted is also easier for a human to understand and confirm that it is correct.
when you declare a property with retain like this
#property(nonatomic,retain) UIImageView *tstImageView;
a setter is added that will incr the retainCount when you assign to the property. When you do as below the object you created has already a retainCount == 1
self.tstImageView = [[UIImageView alloc]
initWithFrame:<SomeFrame>];
so the tstImageView object has 2 in retainCount.
do instead
UIImageView* view = [[UIImageView alloc] initWithFrame:<SomeFrame>];
self.tstImageView = view;
[view release];
then, although unrelated to your leak when you release it write like this instead
self.tstImageView = nil;
since the setter will then will properly set the retainCount
I've read a lot of UIScrollView with UIImageView threads here or other googled pages. But I still cannot get the problem I'm confronting. I'm having a cold right now. Hope I can still make it clear, lol. Here is the problem:
I'm building one app which mainly uses UIScrollView to display a few images. Here the amount counts, not the size, which is averagely 100KB(I even converted PNG to jpg, not sure whether it helps or not). With no more than 10 images, my app crashes with memory warning. This is the first time I encounter memory issue, which surprised me as the compiled app is less than 10MB.
At the very beginning, I load all the images on launch, looping all names of image files and do
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:imgName]];
[scrollview addSubview:imageView];
[imageView release];
If I'm right, I think after launch, all the images are in memory, right? But the funny thing here is, the app could launch without any problem(at most a level 1 memory warning). After I scroll a few images, it crashed. I checked leaks for sure and also allocations. No leak and allocation almost had no change during scrolling.
So, is there something special done by imageNamed rather than cache?
And then, yes, I turned to lazy load.
For fear of checking page and loading images on demand might jerk the scrolling(which was proved true), I used a thread which runs a loop to check offset of the scroll view and load/unload images.
I subclassed UIImageView by remembering the image name. It also contains loadImage and unloadImage which will be executed on that thread.
- (void)loadImage {
/if ([self.subviews count] == 0) {
UIImageView iv = [[UIImageView alloc] initWithImage:[UIImage imageNamed:self.imageName]];
[self performSelectorOnMainThread:#selector(renderImage:) withObject:iv waitUntilDone:NO];
//[self addSubview:iv];
[iv release];
}*/
if (self.image == nil) {
//UIImage *img = [UIImage imageNamed:self.imageName];
UIImage *img = [[UIImage alloc] initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:[self.imageName stringByDeletingPathExtension] ofType:[self.imageName pathExtension]]];
// image must be set on main thread as UI rendering is main thread's responsibility
[self performSelectorOnMainThread:#selector(renderImage:) withObject:img waitUntilDone:NO];
[img release];
}
}
// render image on main thread
- (void)renderImage:(UIImage*)iv {
//[self addSubview:iv];
self.image = iv;
}
(void)unloadImage {
self.image = nil;
//[(UIView*)[self.subviews lastObject] removeFromSuperview];
}
You can see the commented code that I've played with.
In unloadImage, if I write [self.image release], then I get EXC_BAD_ACCESS, which is unexpected, as I think alloc and release are matched here.
The app still crashes with no leak. The initWithContentsOfFile version even crashed earlier than imageNamed version, and made the scrolling not that smooth.
I run the app on device. By checking allocations, I found imageNamed version used much less memory than initWithContentsOfFile version, though they both crash. Instruments also showed that the allocated images were 2,3 or 4, which indicated the lazy load did do his job.
I checked PhotoScroller of WWDC2010, but I don't think it solvs my problem. There is no zooming or huge picture involved.
Anybody helps! Thank you in advance.
The crash log says nothing. The app crashes mostly after memory warning level = 2. And if run on simulator, there will be no problem.
It doesn't matter which format do you use for your images. They're converted to bitmaps when you display them.
I'd suggest to use the technique similar to that one which is used by UITableView (hide the image and free the memory it uses when it disappears from the screen and instantiate the image only when you need to show it).
As an alternate way – if you need to show these images in a grid – you might take a look to a CATiledLayer.
Anyhow, loading all the images to the memory is not the best idea :)
You can load all the images to an array. And you can design a view having one image view and try the below code:
array name: examplearray and view name :exampleview
-(void)updateImagesInScrollView
{
int cnt = [examplearray count];
for(int j=0; j< cnt; ++j)
{
NSArray *nibContents = [[NSBundle mainBundle] loadNibNamed:#"exampleview"
owner:self
options:nil];
UIView *myView = [nibContents objectAtIndex:0];
exampleview * rview= (exampleview *)myView;
/* you can get your iamge from the array and set the image*/
rview.imageview.image = yourimage;
/*adding the view to your scrollview*/
[self.ScrollView addSubview:rview];
}
/* you need to set the content size of the scroll view */
self.ScrollView.contentSize = CGSizeMake(X, self.mHorizontalScrollView.contentSize.height);
}
I am developing an game in which i have to load images on finger swipe. For this i loaded all image 22 of size (788x525) at loading of the view itself. Then on finger swipe i just added image on view.
This works fine on iTouch but on iPhone game crashes after showing near about 12 images.
This is how i added images, graphicsArray is NSMUTableArray.
for ( int i=0; i<=totalNoofPages;i++){
NSString * graphicsFileName = #"Page";
graphicsFileName =
[graphicsFileName
stringByAppendingString:[NSString stringWithFormat:#"%d", i]];
UIImage *image =
[[UIImage alloc] initWithContentsOfFile:
[[NSBundle mainBundle] pathForResource:graphicsFileName
ofType:#"jpg"]];
GraphicsImages =
[[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 480,320 )];
GraphicsImages.image = image;
[image release];
[GraphicsImages setCenter:center];
GraphicsImages.transform = CGAffineTransformMakeRotation(M_PI/2);
[graphicsArray insertObject:GraphicsImages atIndex:i];
}
and on finger swipe i write,pageNo is number of page that will be displayed.
GraphicsImages = [graphicsArray objectAtIndex:pageNo];
[self addSubview:GraphicsImages];
Is there any way to release the previous loaded image from sub view as it might be kept on stack or is it due to large image size????
Please help me in this situation.
Thanks in advance.
Regards,
Vishal.
Are you crashing due to lack of memory?
You might try pre-loading the previous, current & next images only, and release them as soon as possible. Loading 22 images in memory takes up quite a lot of space.
Can you provide the error that you're getting when the app crashes? Knowing what exception is being triggered will help a lot in figuring out exactly what's going on.
I can tell you that you aren't releasing the GraphicsImages variable in your for loop, so that's causing memory leaks. I imagine that that's not enough to cause a crash, however. In any case, do this:
[ graphicsArray insertObject:GraphicsImages ];
[ GraphicsImages release ];
Note that you don't need to specify the insertion index in your case because the items will be added sequentially. Also, when you insert an object into an array, it is retained, so you can safely release it afterwards.