I have seen that a few others have had this problem as well.
I'm trying to follow a tutorial online that shows how to create animated pins on a MapView.
I have implemented the code as shown in the tutorial and the project builds fine except I receive this exception:
-[MKPointAnnotation iconN]: unrecognized selector sent to instance
I have a subclass of 'MKPinAnnotationView' and in the .m file I create this method:
- (void)setAnnotation:(id<MKAnnotation>)annotation {
[super setAnnotation:annotation];
//Place *place = [[Place alloc] init];
Place *place = (Place *)annotation;
//The following line is where the program sends "SIGABRT"
icon = [UIImage imageNamed:[NSString stringWithFormat:#"pin_%d.png", [place.iconN intValue]]];
[iconView setImage:icon];
}
Here are a few parts from my "model" which is called Place.h/.m.
Here is where I create the property for 'iconN'.
#property (retain, nonatomic) NSNumber *iconN;
And here I synthesize it:
#synthesize iconN = _iconN;
Any help is greatly appreciated.
EDIT:
Here is the Place.h and Place.m
#import <MapKit/MapKit.h>
#import <CoreLocation/CoreLocation.h>
#interface Place : NSObject <MKAnnotation> {
CLLocationCoordinate2D coordinate;
NSString *title;
}
#property (retain, nonatomic) NSNumber *iconN;
#property (nonatomic, copy) NSString *title;
#property (nonatomic) CLLocationCoordinate2D coordinate;
- (id)initWithLong:(CGFloat)lon Lat:(CGFloat)lat iconNumber:(NSNumber *)iconNumber;
#end
And the Place.m
#import "Place.h"
#implementation Place
#synthesize coordinate;
#synthesize iconN = _iconN;
#synthesize title;
- (id)initWithLong:(CGFloat)lon Lat:(CGFloat)lat iconNumber:(NSNumber *)iconNumber {
self = [super init];
if (self) {
coordinate = CLLocationCoordinate2DMake(lat, lon);
self.iconN = iconNumber;
}
return self;
}
- (NSString *)title {
return [NSString stringWithFormat:#"Bus: %d", [self.iconN intValue]];
}
- (NSString *)subtitle {
return [NSString stringWithFormat:#"bus[%d] from database.", [self.iconN intValue] - 1];
}
#end
You cannot convert a MKAnnotation to a Place just by casting it. This line is wrong.
Place *place = (Place *)annotation;
You should post your Place.h and Place.m files if you're still stuck. You need to either set the iconN property on a new Place object, or create an init method in the Place class that accepts the MKAnnotation object as a parameter and sets it own internal values accordingly.
In the line
Place *place = (Place *)annotation;
has the variable place of annotation variable class (MKPointAnnotation), you are not able to bring the master class variable to a subclass in this way. Instead you'll have to make a constructor for Place from MKPointAnnotation and perform a check in the setAnnotation method that annotation is of MKPointAnnotation.
You are sending the message to the annotation but you seem to have subclasses the annotation view.
Posting as an answer what was originally just a comment:
I'm not familiar with the MapKit, but the thing that sticks out for me in this: -[MKPointAnnotation iconN]: unrecognized selector sent to instance is that the class is MKPointAnnotation. So the annotation you're receiving isn't actually a Place object, it's an MKPointAnnotation object - you can't just cast to Place. I suspect the root of your problem is where you create your annotation object in the first place.
Related
I'm trying to make a custom MKAnnotation class so it can hold additional information but i keep getting this error :
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '- [AnnotationForId setCoordinate:]: unrecognized selector sent to instance 0x16f63340'
I've tried looking up how to create one and i've followed what i've found online and i'm confused at why i keep getting this error.
Here is my custom annotation class.
#import <MapKit/MapKit.h>
#import <UIKit/UIKit.h>
#interface AnnotationForId : NSObject <MKAnnotation >{
NSString *title;
NSString *subtitle;
CLLocationCoordinate2D coordinate;
NSInteger shopId;
}
#property(nonatomic)NSInteger shopId;
#property (nonatomic, copy) NSString * title;
#property (nonatomic, copy) NSString * subtitle;
#property (nonatomic, readonly) CLLocationCoordinate2D coordinate;
#end
I've synthesized the property variables in .m class.
I try to call the custom class in my main controller:
for(Shop *shops in feed.shops){
NSLog(#"reached");
AnnotationForId *shop = [[AnnotationForId alloc] init];
CLLocationCoordinate2D coords = CLLocationCoordinate2DMake(shops.latitude, shops.longitude);
shop.coordinate = coords;
//[[CLLocationCoordinate2DMake(shops.latitude, shops.longtitude)]];
shop.title = shops.name;
shop.subtitle = #"Coffee Shop";
[map addAnnotation:shop];
}
Any help to why this isnt working would be awesome.
Thanks.
It seems like you're trying to set your readonly property.
You declared it as readonly:
#property (nonatomic, readonly) CLLocationCoordinate2D coordinate;
But then you're trying to use setter:
shop.coordinate = coords;
readonly means that no setter will be defined for other classes to leverage.
Edit:
I think you should add convenience initializer to your AnnotationForId class like:
-(id)initWithCoordinate:(CLLocationCoordinate2D)coord
{
self = [super init]; // assuming init is the designated initialiser of the super class
if (self)
{
coordinate = coord;
}
return self;
}
So your code will look like this:
for(Shop *shops in feed.shops){
NSLog(#"reached");
CLLocationCoordinate2D coords = CLLocationCoordinate2DMake(shops.latitude, shops.longitude);
AnnotationForId *shop = [[AnnotationForId alloc] initWithCoordinate:coords];
//[[CLLocationCoordinate2DMake(shops.latitude, shops.longtitude)]];
shop.title = shops.name;
shop.subtitle = #"Coffee Shop";
[map addAnnotation:shop];
}
This is Simple Example For how to Create Custom AnnotationView.
Create custom AnnotationView:
#import <MapKit/MapKit.h>
#interface AnnotationView : MKPlacemark
#property (nonatomic, readwrite, assign) CLLocationCoordinate2D coordinate;
#property (nonatomic, strong) NSString *title;
#property (nonatomic, strong) NSString *subtitle;
// you can put here any controllers that you want. (such like UIImage, UIView,...etc)
#end
And in .m file
#import "AnnotationView.h"
#implementation AnnotationView
- (id)initWithCoordinate:(CLLocationCoordinate2D)coordinate addressDictionary:(NSDictionary *)addressDictionary
{
if ((self = [super initWithCoordinate:coordinate addressDictionary:addressDictionary]))
{
self.coordinate = coordinate;
}
return self;
}
#end
// Use Annotation Add #import "AnnotationView.h" in your relevant .m file:
CLLocationCoordinate2D pCoordinate ;
pCoordinate.latitude = LatValue;
pCoordinate.longitude = LanValue;
// Create Obj Of AnnotationView class
AnnotationView *annotation = [[AnnotationView alloc] initWithCoordinate:pCoordinate addressDictionary:nil] ;
annotation.title = #"I m Here";
annotation.subtitle = #"This is Sub Tiitle";
[self.mapView addAnnotation:annotation];
Above is simple Example of how to create AnnotationView.
You have given the property as readonly, which sets only a getter method for the property. So please make the property retain and try it once again.
I'm setting a string in a view controller called ViewController and trying to access it somewhere else. This is the code:
ViewController.h
NSString *string;
...
#property (retain) NSString *string;
ViewController.m
#synthesize string;
...
-(void)viewDidLoad {
...
string = #"Test";
}
OtherViewController.m
#import "ViewController.h"
...
-(void)viewDidLoad {
ViewController *vc;
vc = [[ViewController alloc] init];
NSLog(#"String: %#", vc.string);
}
However, the log is showing: String: (null). What am I doing incorrectly? Thanks.
The viewDidLoad of ViewController is only called when the view is loaded. The view is lazily loaded when required e.g. when a call to vc.view is made.
I'm not sure what you are trying to achieve but this certainly seems like a code smell to me.
As #Fscheidl points out you are creating a new instance and not accessing an existing instance so this may add to your problem. I still believe your main issue is that you assume viewDidLoad is being called just by creating the viewController, which is not the case
edit : it doesn't necessarily need to be an NSObject class, if you want to, you could also do this on your viewController class, just be sure to also include
-(id)init
on your header
---- end of edit
if you're trying to make a class that's accessible to another view controller, why not try NSObject instead of view controller (considering you only need to take that string value)
for instance, lets call that viewController class "global" class
so at global.h, you put up
#import <Foundation/Foundation.h>
#interface GlobalVar : NSObject
#property (nonatomic, strong) NSString *myString;
-(id)init;
#end
and then, at global.m you put up
#import "GlobalVar.h"
#implementation GlobalVar
#synthesize myString;
-(id)init
{
self = [super init];
if(self)
{
myString = [[NSString alloc]initWithFormat:#"the String"];
}
return self;
}
#end
after this, everytime you need to access the "myString" object that contained in global class, you could put up
at header :
#import "GlobalVar.h"
...
...
#property (nonatomic, strong) GlobalVar *globalVar;
at implementation file :
#synthesize globalVar;
...
...
self.globalVar = [[GlobalVar alloc]init];
NSString *theString = globalVar.myString;
NSLog(#"content of my string is : %#",theString);
there you go ;)
You do create a new instance of ViewController by calling [[ViewController alloc] init]; This instance hasn't had string even set. You have to access that exact instance of ViewController.
If you create the instance of OtherViewController directly from ViewController, you can add the following to OtherViewController.h:
#import "ViewController.h"
#property (nonatomic, retain) ViewController *previousViewController
When creating the OtherViewController, you can then set:
//alloc and init instance of OtherViewController
myOtherViewController.previousViewController = self;
In your viewDidLoad: method, you can then access your string as follows:
NSLog(#"String: %#", previousViewController.string);
I am passing an NSDictionary object from one view class to another as I transition from a table view to a normal view to show details:
Passing Controller:
[tweetController setTweet:tweet];
Receiving Controller.h:
#interface TweetViewController : UIViewController {
NSDictionary *tweet;
}
#property (nonatomic, retain) NSDictionary *tweet;
Receiving Controller.m:
#implementation TweetViewController
#synthesize tweet = _tweet;
I then try to use this information to set the properties of some fields in my view:
- (void)viewDidLoad
{
[super viewDidLoad];
tweetLabel.text = [_tweet objectForKey:#"text"];
}
The result is a blank label and if I inspect the value of _tweet at this stage it is nil.
I originally had a method which set the value of tweet which I called at the same location as I am now setting the value. If I inspected the value at this stage it was fine.
I presume that the automagic setter through #synthasize is working, but somewhere else the value is being lost.
Sorry this is my first objective C anything! Thanks for any help in advance.
You are using your "tweet" instance variable, whereas the "tweet" property is synthesized to the "_tweet" variable.
You are probably calling the setTweet method after viewDidLoad executes.
I usually pass this kind of thing into a custom init method.
Alternatively, you could do the set before pushing the detail VC onto the nav stack.
Are you sure that tweetLabel isn't nil?
I've made a few corrections & optimisations to your code. You don't need to declare ivars in the header file anymore, they are generated automatically by #synthesize
- (void)dealloc; is only needed if you're not using ARC.
//.h
#interface TweetViewController : UIViewController
#property (strong, nonatomic) NSDictionary *tweet;
#property (strong, nonatomic) IBOutlet UILabel *tweetLabel
#end
//.m
#implementation TweetViewController
#synthesize tweet = _tweet;
#synthesize tweetLabel = _tweetLabel;
- (void)viewDidLoad {
[super viewDidLoad];
self.tweetLabel.text = [self.tweet objectForKey:#"text"];
}
- (void)dealloc {
[_tweet release];
[_tweetLabel release];
[super dealloc];
}
#end
Note: strong is equivalent to retain
To expand on #Rayfleck's answer, since you are new to Objective-C, your custom init method could look like this:
In TweetViewController.h:
- (id)initWithTweet:(NSDictionary*)tweet;
In TweetViewController.m:
- (id)initWithTweet:(NSDictionary*)tweet
{
self = [super init];
if (self) {
_tweet = tweet;
}
return self;
}
and then in your passing controller you'd allocate and initialize like this:
TweetViewController *tvc = [[TweetViewController alloc] initWithTweet:myTweet];
I have a mapview where i update my currentlocation with CoreLocation, but I also have checks which uses userLocation.
I still haven't found an alternative in fixing my problem
But for some reason I can't use userLocationVisible to hide the blue dot.
When I enter my MapView I start the locationManager, but before I have updated my location, the blue dot appears and my pin doesn't show up.
I've tried to use a custom MKAnnotation and init the coordinates with the newLocation from DidUpdateToLocation. But when I run this I get:
-[CustomPlacemark setCoordinate:]: unrecognized selector sent to instance 0x1de6c0
this is my CustomPlacemark:
#import <Foundation/Foundation.h>
#import <MapKit/MapKit.h>
#interface CustomPlacemark : NSObject<MKAnnotation> {
CLLocationCoordinate2D coordinate;
NSString *title;
NSString *subtitle;
}
#property (nonatomic, readonly) CLLocationCoordinate2D coordinate;
#property (nonatomic, retain) NSString *title;
#property (nonatomic, retain) NSString *subtitle;
-(id)initWithCoordinate:(CLLocationCoordinate2D) coordinate;
- (NSString *)subtitle;
- (NSString *)title;
#end
#import "CustomPlacemark.h"
#implementation CustomPlacemark
#synthesize coordinate;
#synthesize title, subtitle;
-(id)initWithCoordinate:(CLLocationCoordinate2D) c{
self=[super init];
if (self!=nil) {
coordinate=c;
}
return self;
}
-(NSString*)title{
return title;
}
-(NSString*)subtitle{
return subtitle;
}
-(void) dealloc
{
[title release]; title = nil;
[subtitle release]; subtitle = nil;
[super dealloc];
}
#end
Can someone also tell me why I can't use UserLocationVisible??
cordinate is read only property for customplacemark class . so u can not set cordinate property. to set cordinate property make it read and write.
change line#property (nonatomic, readonly) CLLocationCoordinate2D coordinate;
To #property (nonatomic, readwrite) CLLocationCoordinate2D coordinate;
The right way to do it will be initWithCoordinate rather than making the property readwrite
The blue dot appears when you set showsUserLocation=YES; If you want to hide the blue dot, set this to NO. Alternatively, you can determine if the user's location is visible on the screen using CoreLocation and enable showsUserLocation to YES.
Also, the blue dot is a special annotation class MKUserLocation that conforms to MKAnnotation protocol. If you are sending any messages to annotation objects that are your own class, you may want to exclude MKUserLocation annotation object.
If you want to know how to specifically deal with your custom annotation objects without sending incorrect messages to MKUserLocation class, let me know, I have the code that I can send.
I simply want to change a variable of an object from another class. I can compile without a problem, but my variable always is set to 'null'.
I used the following code:
Object.h:
#interface Object : NSObject {
//...
NSString *color;
//...
}
#property(nonatomic, retain) NSString* color;
+ (id)Object;
- (void)setColor:(NSString*)col;
- (NSString*)getColor;
#end
Object.m:
+(id)Object{
return [[[Object alloc] init] autorelease];
}
- (void)setColor:(NSString*)col {
self.color = col;
}
- (NSString*)getColor {
return self.color;
}
MyViewController.h
#import "Object.h"
#interface ClassesTestViewController : UIViewController {
Object *myObject;
UILabel *label1;
}
#property UILabel *label1;
#property (assign) Object *myObject;
#end
MyViewController.m:
#import "Object.h"
#implementation MyViewController
#synthesize myObject;
- (void)viewDidLoad {
[myObject setColor:#"red"];
NSLog(#"Color = %#", [myObject getColor]);
[super viewDidLoad];
}
The NSLog message is always Color = (null)
I tried many different ways to solve this problem, but no success.
Any help would be appreciated.
Thanks for the help so far.
I modified the code as follow, but it still doesn't work as it should.
MyViewController.h:
#import <UIKit/UIKit.h>
#import "Object.h"
#interface MyViewController : UIViewController {
Object *myObject;
}
#property (nonatomic, retain) Object *myObject;
#end
MyViewController.m:
#import "MyViewController.h"
#import "Object.h"
#implementation MyViewController
#synthesize myObject;
- (void)viewDidLoad {
Object *myObject = [Object new];
myObject = 0;
[myObject setColor:#"red"];
NSLog(#"color = %#", myObject.color);
[super viewDidLoad];
}
If I do it like this, NSLog returns color = null (and I think myObject is only visible in viewDidLoad). How can declare myObject and make it visible in MyViewController?
I stripped down my Object class to
Object.h:
#interface Object : NSObject {
NSString *color;
}
#property(nonatomic, retain) NSString *color;
#end
Object.m:
#import "Object.h"
#implementation Object
#synthesize color;
#end
I wasn't able to define an object myObject in ViewDidLoad so that I can access its properties from the whole ViewController class? What did I miss?
Side question: Why do I have to set myObject to 0?
You're declaring a property, then explicitly declaring the accessors in Object.h. You only need to do one or the other - they mean the same thing (well, almost - you'll have color instead of getColor)
To implement the property in Object.m you should use #synthesize color. The explicit implementations, again, are then redundant (unless they do anything extra).
The explicit setColor implementation in Object.m is calling the property - which you are implementing explicitly, so I would have expected you to get an infinite recursion here.
MyViewController.m should probably synthesize label1, since you declare the property in the header (although it's not being used in your snippet).
[myObject getColor] is calling the color property, which you declared but did not synthesize. If you had explicitly implemented it as color it would have picked that up - but it won't match getColor (which is fortunately as that would have led to an infinite recursion again.
I don't see anywhere where you create your myObject instance. If you don't it will be nil and methods called on it (including property accesses) will return 0 or nil.
I suspect (6) is the cause of your issue, but the others need to be addressed too. Make sure you read up on property syntax.