In my application when the user touches the screen, I put an UIImageView on the screen like this:
- (void) drawPoint:(CGPoint) toLocation {
UIImageView *image = [[UIImageView alloc] initWithFrame:CGRectMake(toLocation.x, toLocation.y, SIZE_X, SIZE_Y)];
image.tag = 1;
[image setImage:[UIImage imageNamed:#"point.png"]];
[self.myView addSubview:image];
[image release];
}
Here MyView is an UIView.
When the user has finished touching, I want to remove my UIImageView. I have tried this:
- (void) removeFromPoint:(CGPoint) location{
UIImageView *image;
[[image viewWithTag:1] removeFromSuperview];
}
or
- (void) removeFromPoint:(CGPoint) location{
UIImageView *image = (UIImageView *)[self.MyView viewWithTag:1];
[image removeFromSuperview];
}
but both of them end up in EXC_BAD_ACCESS.
Do you know how can I accomplish this?
Thanks.
If you want to remove uimage under the touch try this:
UIView * imageView = [self.myView hitTest:location withEvent:nil];
if ([imageView isKindOfClass:[UIImageView class]] && imageView.tag == 1) {
[imageView removeFromSuperview];
}
(note I've typed it here, i haven't test that code)
If you wish to debug your code enable NSZombies and check why you gets the bad_access. (check this to learn more about NSZombieEnabled http://www.cocoadev.com/index.pl?NSZombieEnabled)
If you are going to add only one view. Then I would store it in a retained property and I would add/remove it on events like this:
#property (nonatomic,retain) UIImageView* marker;
#interface
#syntesize marker;
-(void) onTouchDown {
[self.view addSubview:marker];
}
-(void) onTouchUp {
[marker removeFromSuperview];
}
The first example of removing image view is wrong.
In the second one what is POINT_TAG equal to?
Try to use tag greater then 9.
Try to debug what UIImageView *image = (UIImageView *)[self.MyView viewWithTag:POINT_TAG];
returns.
Related
Here's my view hierarchy: parentView (UIView) has a UIImageView as its subview which in turn has a UIButton as its subview.
left = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"left.png"]];
left.userInteractionEnabled = YES;
[parentView addSubview:left];
back = [UIButton buttonWithType:UIButtonTypeCustom];
[back setImage:[UIImage imageNamed:#"Arrow-left.png"] forState:UIControlStateNormal];
[back addTarget:self action:#selector(back:) forControlEvents:UIControlEventTouchUpInside];
back.showsTouchWhenHighlighted = YES;
[left addSubview:back];
Everything shows up properly but the button does not respond to touches. It does respond if I move its frame out of the UIImageView's frame to somewhere else and set it as a subView to the parentView (UIView). But here's the thing.
Even if I set to parentView's subView the button does not respond if it is within the UIImageView's frame area. The userInteractionEnabled property has been already set to YES for the image view. Any idea what's going on?
UIImageView turns off userInteraction - turn it on and the button will work.
EDIT:
So I used your code almost exactly as written - the one red herring is that you said it all appears fine. For me, the custom button had a frame of 0,0,0,0 so I saw nothing. When I set the frame it all worked perfectly:
UIButton *back = [UIButton buttonWithType:UIButtonTypeCustom];
UIImage *image = [UIImage imageNamed:#"46-truck.png"];
assert(image);
[back setImage:image forState:UIControlStateNormal];
[back addTarget:self action:#selector(buttonAction:) forControlEvents:UIControlEventTouchUpInside];
back.showsTouchWhenHighlighted = YES;
back.frame = (CGRect){ {0,0}, image.size};
NSLog(#"FRAME: %#", NSStringFromCGRect(back.frame) );
[imageView addSubview:back];
So, if you need to probe the superviews during run time to figure out what is what, you can use this code below. [UIView dumpSuperviews:back msg:#"Darn Bark Button"];
#interface UIView (Utilities_Private)
+ (void)appendView:(UIView *)v toStr:(NSMutableString *)str;
#end
#implementation UIView (Utilities_Private)
+ (void)appendView:(UIView *)a toStr:(NSMutableString *)str
{
[str appendFormat:#" %#: frame=%# bounds=%# layerFrame=%# tag=%d userInteraction=%d alpha=%f hidden=%d\n",
NSStringFromClass([a class]),
NSStringFromCGRect(a.frame),
NSStringFromCGRect(a.bounds),
NSStringFromCGRect(a.layer.frame),
a.tag,
a.userInteractionEnabled,
a.alpha,
a.isHidden
];
}
#end
#implementation UIView (Utilities)
+ (void)dumpSuperviews:(UIView *)v msg:(NSString *)msg
{
NSMutableString *str = [NSMutableString stringWithCapacity:256];
while(v) {
[self appendView:v toStr:str];
v = v.superview;
}
[str appendString:#"\n"];
NSLog(#"%#:\n%#", msg, str);
}
+ (void)dumpSubviews:(UIView *)v msg:(NSString *)msg
{
NSMutableString *str = [NSMutableString stringWithCapacity:256];
if(v) [self appendView:v toStr:str];
for(UIView *a in v.subviews) {
[self appendView:a toStr:str];
}
[str appendString:#"\n"];
NSLog(#"%#:\n%#", msg, str);
}
#end
Maybe
parentView.userInteractionEnabled = YES;
Or parent view frame are to small and can`t hold button or image view. Check size of parent view;
I've had this happen before.. I think it was a super view swallowing the event.
I know you've stated that adding it to the parentView only works if it doesn't overlap with the image view. If you disable user interaction on the image view, does the button event trigger consistently when added to the parentView?
You actually need to set userInteractionEnabled = NO to allow the touches to pass through.
Taken from here.
left.userInteractionEnabled = YES;
put this line in the end.
This is my first post and you are my last hope.
I have a list with images in my iPad app, if you select one, my class MyViewController which extends UIViewController is loaded and shown (by just setting window.rootViewController, by using UINavigationController, by presentModalViewController - tried everything, doesn't make any difference). It has a UIScrollView inside, which adds a big version of the image to the UIScrollView with this code:
UIImageView *tempImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:[[delegate getImageNames] objectAtIndex:(gameNr*2)]]];
tempImageView.frame = CGRectMake(0,0,tempImageView.frame.size.width/2,tempImageView.frame.size.height/2);
[self setMyImage:tempImageView];
[tempImageView release];
myScrollView.contentSize = CGSizeMake(myImage.frame.size.width, myImage.frame.size.height);
myScrollView.maximumZoomScale = 2.0;
myScrollView.minimumZoomScale = 1.0;
myScrollView.clipsToBounds = YES;
myScrollView.bounces = NO;
myScrollView.delegate = self;
[myScrollView addSubview: myImage];
myImage is a (nonatomic, retain) property of the type UIImageView inside my MyViewController.
After pressing a button and go back to the list of images, I release the reference to MyViewController and it's dealloc method is called like this:
- (void)dealloc
{
CFShow(#"dealloc!");
for(UIImageView *subview in [myScrollView subviews]) {
if(subview.frame.size.width > 20){
[subview removeFromSuperview];
[subview setImage:nil];
}
}
[myImage setImage:nil];
self.myScrollView = nil;
self.myImage = nil;
[myScrollView release];
[myImage release];
[super dealloc];
}
It works so far, but the problem is, that the memory of the images is not really deallocated this way. After opening and closing about 12 images, the app crashes with memory warning.
This is also confirmed by the report_memory method I got from here:
iOS Low Memory Crash, but very low memory usage
The dealloc method IS called, that's triple checked.
I checked the variables myImage and myScrollViewvia breakpoint in the debugger, they are set to 0x0 by those commands in the dealloc method. Why is the memory not freed????????
Thanks for any suggestion, I am working on this since three whole days, it's driving me crazy.
Replace this:
self.myScrollView = nil;
self.myImage = nil;
[myScrollView release];
[myImage release];
with this:
[myScrollView release];
self.myScrollView = nil;
self.myImage = nil;
And post code where you define property myScrollView and init it.
And you don't need loop for(UIImageView *subview in [myScrollView subviews]). When you will release myScrollView object it will automatically release all its subviews.
I'm using the following categories code to change
the background image of the navigation bar
#import <Foundation/Foundation.h>
#interface UINavigationBar (CustomImage)
- (void) setBackgroundImage:(UIImage*)image;
- (void) clearBackgroundImage;
#end
#import "UINavigationBar+CustomImage.h"
#implementation UINavigationBar (CustomImage)
- (void) setBackgroundImage:(UIImage*)image {
if (image == NULL) return;
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
imageView.frame = CGRectMake(0, 0, self.frame.size.width, self.frame.size.height);
[self insertSubview:imageView atIndex:0];
[imageView release];
}
- (void) clearBackgroundImage {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
NSArray *mySubviews = [self subviews];
for (int i = [mySubviews count] - 1; i >= 0; i--)
{
if ([[mySubviews objectAtIndex:i] isMemberOfClass:[UIImageView class]])
{
[[mySubviews objectAtIndex:i] removeFromSuperview];
return;
}
}
[pool release];
}
#end
And i'm using the following code to generate the custom back button
in my view
UIButton *btnBack = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 40, 40)];
[btnBack addTarget:self action:#selector(goBack) forControlEvents:UIControlEventTouchUpInside];
[btnBack setImage:[UIImage imageNamed:#"back.png"] forState:UIControlStateNormal];
UIBarButtonItem *barBtnBack = [[UIBarButtonItem alloc] initWithCustomView:btnBack];
self.navigationItem.leftBarButtonItem = barBtnBack;
[btnBack release];
[barBtnBack release];
But the button most of the time is hidden under the bg image
and some times it randomly appears.
Why is this happening? I'm not sure what's the problem the image is inserted at index 0
so as I understand it is supposed to be behind all the time.
Please help.
Try the following code to change background of the navigation bar in the class where you are loading the navigation bar.
#interface UINavigationBar (MyCustomNavBar)
#end
#implementation UINavigationBar (MyCustomNavBar)
- (void) drawRect:(CGRect)rect
{
UIImage *barImage = [UIImage imageNamed:#"image.png" ];
[barImage drawInRect:rect];
}
#end
Using the method Praveen S suggested you could have a global variable for the next background image name and set it in your viewDidLoad method, then in your draw rect method use the imageName stored in the variable rather than hardcoding it in the draw rect.
You should try creating the button after adding the image.
i have images in my UIScrollview which is added in View.
plz go through my code-
#interface ScrollViewController : UIScrollView <UIScrollViewDelegate>{
UIImageView *productImage;
UILabel *productName;
NSArray *productArray;
}
#property(nonatomic,retain) UIImageView *productImage;
#property(nonatomic,retain) UILabel *productName;
#property(nonatomic,retain) NSArray *productArray;
- (id)initWitProducts:(NSArray*)_data;
*.m*
- (id)initWitProducts:(NSArray *)_data
if ((self = [super init])){
productArray=[[NSArray alloc]initWithArray:_data];
[self setFrame:CGRectMake(0, 0, 320, 480)];
int countList=[self.productArray count];
self.contentSize=CGSizeMake(320, 585);
for(int i=0;i<countList;i++)
{
productImage=[[UIImageView alloc]initWithImage:[UIImage imageNamed:[[productArray objectAtIndex:i]objectForKey:#"ProductImage"]]];
productImage.frame=CGRectMake(95, 35+i*125, 100, 100);
[productImage setUserInteractionEnabled:YES];
[self addSubview:productImage];
}
return self;
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent*)event
{
if([[touches anyObject]view]==self.productImage)
NSlog(#"Image Touched");
}
This is working well but only for last image in Array
the touchesBegan is not working for other images in Array
what should i add here to detect the touch on all the images(1st,2nd,...etc) of Array
You know all the positions of images on UIScrollview, so you can touch position on scrollView into images position in you array.
And another point - you should never compare objective-c objects using "==", always use "isEqual" method instead.
That is because you keep on updating the variable productImage, change your code to read
UIImageView *imageInstance=[[UIImageView alloc]initWithImage:[UIImage imageNamed:[[productArray objectAtIndex:i]objectForKey:#"ProductImage"]]];
imageInstance.frame=CGRectMake(95, 35+i*125, 100, 100);
[imageInstance setUserInteractionEnabled:YES];
[self addSubview:imageInstance];
Is it possible to allow user input text on a UIImageView, just like the text tool in painter?
I cannot find any resource on this topic?
UIImageView is not designed to hold any text, but you could add a UILabel or UITextField either within it or on top / below it, depending on what you want to do.
For example, suppose you want to allow the user to edit a piece of text inside an image. You could do something like this:
UIImage* image = [UIImage imageNamed:#"my_image.png"];
UIImageView* imageView = [[UIImageView alloc] initWithImage:image];
imageView.userInteractionEnabled = YES;
UITextField* textField = [[UITextField alloc]
initWithFrame:CGRectMake(10, 10, 50, 20)];
textField.placeholder = #"type here";
[imageView addSubview:textField];
// You might also want to set the imageView's frame.
[self.view addSubview:imageView];
If you add a UITextField as a subview of a UIImageView, it's important to set the userInteractionEnabled to YES, since it defaults to NO for that superview (it's usually YES by default in most UIViews).
Addendum
If you want the user to be able to click anywhere in the image to edit the text, here is one way to do it: subclass UIControl and add a UIImageView and a UITextField as subviews of it, and connect the clicking action of the UIControl to the UITextField. Something like this (WARNING: not tested code, but it conveys the general idea):
#interface ImageAndTextView : UIControl {
UIImageView* imageView;
UITextField* textField;
}
#property (nonatomic, retain) UIImageView* imageView;
#property (nonatomic, retain) UITextField* textField;
- (void) click;
#end
#implementation ImageAndTextView
#synthesize imageView, textField;
- (id) initWithFrame: (CGRect) frame_ {
if (self = [super initWithFrame:frame_]) {
UIImage* image = [UIImage imageNamed:#"my_image.png"];
self.imageView = [[[UIImageView alloc] initWithImage:image] autorelease];
imageView.userInteractionEnabled = YES;
[self addSubview:imageView];
CGRect textFrame = CGRectMake(10, 10, 50, 20); // whatever frame you want
self.textField = [[[UITextField alloc]
initWithFrame:textFrame] autorelease];
[self addSubview:textField];
// Now register an event to happen if the user clicks anywhere.
[self addTarget:self action:#selector(click)
forEvent:UIControlEventTouchUpInside];
}
return self;
}
- (void) click {
[textField becomeFirstResponder];
}
#end
This is not possible with the current iPhone API (3.1). You will need to create your own custom uitextfields and your own image rendering methods to combine the layers into a captioned photo.