I have a single annotation on a map view. I can select it programmaticly, but the I tap it nothing happens. Could you help me? Did anyone encounter similar problem? Here is mehod for setting up anotations:
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
MKAnnotationView *aView = [mapView dequeueReusableAnnotationViewWithIdentifier:#"MapVC"];
if (!aView) {
aView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:#"MapVC"];
aView.canShowCallout = YES;
aView.draggable=YES;
aView.leftCalloutAccessoryView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 30, 30)];
// could put a rightCalloutAccessoryView here
}
aView.annotation = annotation;
[(UIImageView *)aView.leftCalloutAccessoryView setImage:nil];
return aView;
}
And adding them to map view:
- (void)updateMapView
{
if (self.mapView.annotations) [self.mapView removeAnnotations:self.mapView.annotations];
if (self.annotation) [self.mapView addAnnotation:self.annotation];
}
And mehod reacting to pressing of annotations:
- (void)mapView:(MKMapView *)mapView didSelectAnnotationView:(MKAnnotationView *)aView
{
NSLog(#"did select annotation");
}
By the way, method [self.mapView selectAnnotation:annotation] works, but doesn't put up a callout(i checked it with breakpoint). While just taping annotation doesn't(again cheked through breakpoints).
If an annotation's title is nil or blank, the callout will not show (even if everything else is set properly including canShowCallout).
When you tap on an annotation, the didSelectAnnotationView delegate method will get called and if the annotation has a non-blank title, the callout will be displayed.
Regarding your question in the comments:
...is it right I have a seperate class to wrap all my data in to, my
annotation class contains an instance of that data class?
There's nothing wrong with this.
If you want to keep map-related logic separate from the base class, that's fine and probably a good idea for a complex app where the base data class may be used for more than just annotations.
If your app is very simple and the data is only used for annotations, you could keep things very simple and combine the two but it's not a requirement.
As long as you stick to using direct references instead of trying to, for example, use array indexes or view/button tags to link back to some data object from the annotation, the "right" class implementation depends on what works for your app.
Try setting canShowCallout property of the MKAnnotationView to YES in case you didn't.
Related
i wondering if someone may be able to help me. I am new to xcode and im trying to build a basic app. i have followed this tutorial
http://rshankar.com/how-to-add-annotation-to-mapview-in-ios/
i have copied the source code directly, i don't get any errors or warnings, however when running the app the pin locations do not show. Im not sure if they are there ( just invisible ) or whether they are not showing at all. I can't seem to find the issue.
Would anyone be able to suggest what the problem could be?
Thanks in advance.
actually managed to fix this, turns out the coordinates were round the wrong way!!!! Noob error!! I would like to change the callout on the pins if anyone could shed some light on where to change the code on the tutorial.
Thanks
To change the callout of the pins:
make the class that has your map view implement the <MKMapViewDelegate> protocol
set the delegate of your map view to that class (e.g. mapView.delegate = self;)
implement MKMapViewDelegate's (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation method in that class
something like this:
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
// If it's the user location, just return nil
if ([annotation isKindOfClass:[MKUserLocation class]])
return nil;
// Handle custom annotations
if ([annotation isKindOfClass:[NAME_OF_CLASS_IMPLEMENTING_MKANNOTATION_PROTOCOL class]])
{
// Try to dequeue an existing annotation view first
MKAnnotationView *annotationView = (MKAnnotationView*)[mapView dequeueReusableAnnotationViewWithIdentifier:#"AnnotationViewIdentifier"];
if (!annotationView)
{
// If an existing pin view was not available, create one
annotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:#"AnnotationViewIdentifier"];
annotationView.canShowCallout = YES;
// set callout
UIButton *rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
annotationView.rightCalloutAccessoryView = rightButton;
}
else
{
annotationView.annotation = annotation;
}
return annotationView;
}
return nil;
}
On your map pins (which should be made from a class that implements the MKAnnotation protocol), you should be able to set the title and subtitle properties.
Is there a way to change MKAnnotationView style (like from red label with number to green colored label with number).
I want to change this style according to distance from target. My annotation is moving, with user.
I dont want to use remove / add annotation, because it causes "blinking".
Can it be done someway?
UPDATE:
I am adding code, how I am doing it right now
MKAnnotationView *av = [mapView viewForAnnotation:an];
if ([data->type isMemberOfClass:[UserAnnotationImage class]])
{
UIImage *img = [UIImage imageNamed: ((UserAnnotationImage *)data->type)->url];
[av setImage:img];
}
else if ([data->type isMemberOfClass:[UserAnnotationLabel class]])
{
UIView * v = [av viewWithTag:0];
v = ((UserAnnotationLabel *)data->type)->lbl;
av.frame = ((UserAnnotationLabel *)data->type)->lbl.frame;
}
else if ([data->type isMemberOfClass:[UserAnnotationView class]])
{
UIView * v = [av viewWithTag:0];
v = ((UserAnnotationView *)data->type)->view;
av.frame = ((UserAnnotationView *)data->type)->view.frame;
}
Sadly, its not working :(
Yes, basically you get a reference to the annotation view and update its contents directly.
Another way, if you have a custom annotation view class, is to have the annotation view monitor the changes it is interested in (or have something outside tell it) and update itself.
The first approach is simpler if you are using a plain MKAnnotationView or MKPinAnnotationView.
Wherever you detect that a change to the view is needed, get a reference to the view by calling the map view's viewForAnnotation instance method. This is not the same as calling the viewForAnnotation delegate method.
Once you have a reference to the view, you can modify as needed and the changes should appear immediately.
An important point is that the logic you use to update the view outside the delegate method and the logic you have in the viewForAnnotation delegate method must match. This is because the delegate method may get called later (after you've updated the view manually) by the map view and when it does, the code there should take the updated data into account.
The best way to do that is to have the annotation view construction code in a common method called both by the delegate method and where you update the view manually.
See change UIImage from MKAnnotation in the MKMapView for an example that updates just the annotation view's image.
For an example (mostly an idea for an approach) of updating the view using a custom annotation view class, see iPad Mapkit - Change title of "Current Location" which updates the view's pin color periodically (green, purple, red, green, purple, red, etc).
There are too many unknowns in your code to explain why it doesn't work. For example:
What is data? Is it annotation-specific (is it related to an)? What is type? Does it change after the annotation has been added to the map?
Why is data storing entire view objects like a UILabel or UIView instead of just the underlying data that you want to show in those views?
imageNamed requires the image to be a resource in the project (not any arbitrary url)
Don't use a tag of 0 (that's the default for all views). Start numbering from 1.
You get a view using viewWithTag but then replace it immediately with another view.
I'll instead give a more detailed but simple(r) example...
Assume you have an annotation class (the one that implements MKAnnotation) with these properties (in addition to coordinate, title, and subtitle):
#property (nonatomic, assign) BOOL haveImage;
#property (nonatomic, copy) NSString *labelText;
#property (nonatomic, copy) NSString *imageName;
#property (nonatomic, assign) CLLocationDistance distanceFromTarget;
To address the "important point" mentioned above (that the viewForAnnotation delegate method and the view-update-code should use the same logic), we'll create a method that is passed an annotation view and configures it as needed based on the annotation's properties. This method will then be called both by the viewForAnnotation delegate method and the code that manually updates the view when the annotation's properties change.
In this example, I made it so that the annotation view shows the image if haveImage is YES otherwise it shows the label. Additionally, the label's background color is based on distanceFromTarget:
-(void)configureAnnotationView:(MKAnnotationView *)av
{
MyAnnotationClass *myAnn = (MyAnnotationClass *)av.annotation;
UILabel *labelView = (UILabel *)[av viewWithTag:1];
if (myAnn.haveImage)
{
//show image and remove label...
av.image = [UIImage imageNamed:myAnn.imageName];
[labelView removeFromSuperview];
}
else
{
//remove image and show label...
av.image = nil;
if (labelView == nil)
{
//create and add label...
labelView = [[[UILabel alloc]
initWithFrame:CGRectMake(0, 0, 50, 30)] autorelease];
labelView.tag = 1;
labelView.textColor = [UIColor whiteColor];
[av addSubview:labelView];
}
if (myAnn.distanceFromTarget > 100)
labelView.backgroundColor = [UIColor redColor];
else
labelView.backgroundColor = [UIColor greenColor];
labelView.text = myAnn.labelText;
}
}
The viewForAnnotation delegate method would look like this:
-(MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
if ([annotation isKindOfClass:[MyAnnotationClass class]])
{
static NSString *myAnnId = #"myann";
MKAnnotationView *av = [mapView dequeueReusableAnnotationViewWithIdentifier:myAnnId];
if (av == nil)
{
av = [[[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:myAnnId] autorelease];
}
else
{
av.annotation = annotation;
}
[self configureAnnotationView:av];
return av;
}
return nil;
}
Finally, the place where the annotation's properties change and where you want to update the annotation view, the code would look something like this:
ann.coordinate = someNewCoordinate;
ann.distanceFromTarget = theDistanceFromTarget;
ann.labelText = someNewText;
ann.haveImage = YES or NO;
ann.imageName = someImageName;
MKAnnotationView *av = [mapView viewForAnnotation:ann];
[self configureAnnotationView:av];
I know you can create a custom annotation view using something like:
-(MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
MKPinAnnotationView *annotationView = [[[CustomAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:#"CustomAnnotation"] autorelease];
annotationView.image = [UIImage imageNamed:#"customPin.png"];
return annotationView;
}
.. but how do I change the image in other parts of my code.. (after it has been created with the above)?
You probably don't need the answer anymore, but still, the question is unanswered. What I usually do is add a property to the annotation, telling which image should be used. It can be a BOOL, a UIImage, or pretty much whatever you like.
In viewForAnnotation, I check for that value and set the appropriate image.
Whenever I want to update the image, I change the property's value, and I remove and add the annotation :
[theMapView removeAnnotation: myAnnotation];
[theMapView addAnnotation: myAnnotation];
That way, the annotation is re-drawn.
I was wondering if anyone knows of any subclasses for the MKAnnotationView class. On apples documentation they say one example is the MKPinAnnotationView so I was wondering if there were other pre-created subclasses like the one used to track the devices current location. If anyone has tips for creating my own subclass of the MKAnnotationView class that be great as well.
Thanks,
bubster
In case anyone is still interested in this:
You can get all the subclasses of a class using the Objective-C runtime functions, as described here: http://cocoawithlove.com/2010/01/getting-subclasses-of-objective-c-class.html
Other classes that inherit from MKAnnotationView are:
MKTransitCalloutView, MKAdAnnotationView, MKUserLocationView, MKUserLocationBreadCrumbView, and MKPinAnnotationView
where MKPinAnnotationView is the only one that is documented. All others are private classes that Apple uses internally.
I don't know of any other templates, but that does not mean that they don't exist. :)
Anyway, here's how to create custom ones:
Create a new class conforming to the MKAnnotation protocol. You will need to have two instance variables of type NSString* named title and subtitle and one of type CLLocationCoordinate2D named coordinate and an appropriate setter method (e.g. property). Those strings are going to be displayed in the callout. In the delegate of your mapView, implement the method -mapView:viewForAnnotation: in a similar way as you would implement the datasource for a UITableView. That is, dequeueing an annotationView by an identifier, setting the new properties (e.g. a button of type UIButtonTypeDetailDisclosure for the right accessory view). You will want to add an image to display underneath the offset. Just use the image property of your MKAnnotationView. The center of your custom image will be placed at the coordinate specified, so you may want to give an offset: aView.centerOffset = CGPointMake(0, -20)
Here is some sample code:
- (MKAnnotationView *) mapView: (MKMapView *) mapView viewForAnnotation: (id<MKAnnotation>) annotation {
// reuse a view, if one exists
MKAnnotationView *aView = [mapView dequeueReusableAnnotationViewWithIdentifier:#"pinView"];
// create a new view else
if (!aView) {
aView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:#"pinView"];
}
// now configure the view
aView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
[(UIButton*)aView.rightCalloutAccessoryView addTarget:self action:#selector(showDetails:) forControlEvents:UIControlEventTouchUpInside];
aView.canShowCallout = YES;
aView.enabled = YES;
aView.image = [UIImage imageNamed:#"green_pin.png"];
aView.centerOffset = CGPointMake(0, -20);
return aView;
}
I am managing my own UINavigationBar. I need to do this due to extensive skinning. The documentation for UINavigationController warns that there are limitations to skinning the UINavigationBar when used with a UINavigationController.
I have put in extensive logging and from everything I can tell, pushing the "Back" button in the UINavigationController pops two items off of of the stack instead of one. I get a single delegate callback telling me that it is removing the logical item, but it actually removes that one and one more.
The item added to the UINavigationController in awakeFromNib should never be removed. It is being removed for some reason.
There are two similar questions, but neither have satisfactory answers. The two questions are:
UINavigationBar .items accessor doesn't return the current UINavigationItem
UINavigationBar seems to pop 2 items off stack on "back"
- (void)awakeFromNib {
[headerView setDelegate: self];
[headerView pushNavigationItem: tableDisplay animated: NO];
}
- (void) selectedStory: (NSNotification *)not {
[headerView pushNavigationItem: base animated: NO];
NSLog(#"Selected story: %#", base);
}
- (void) baseNav {
NSLog(#"Current items: %#", [headerView items]);
BaseInnerItem *current = (BaseInnerItem *)[headerView topItem];
[self addSubview: [current view]];
}
- (BOOL)navigationBar: (UINavigationBar *)navigationBar shouldPushItem: (UINavigationItem *)item {
return YES;
}
- (BOOL)navigationBar: (UINavigationBar *)navigationBar shouldPopItem: (UINavigationItem *)item {
return YES;
}
- (void)navigationBar:(UINavigationBar *)navigationBar didPushItem:(UINavigationItem *)item {
NSLog(#"didPushItem: %#", item);
[self baseNav];
}
- (void)navigationBar:(UINavigationBar *)navigationBar didPopItem:(UINavigationItem *)item {
NSLog(#"didPopItem: %#", item);
[self baseNav];
}
Edited to add relevant debugging from a single run:
2010-10-13 02:12:45.911 Remix2[17037:207] didPushItem: <TableDisplay: 0x5d41cc0>
2010-10-13 02:12:45.912 Remix2[17037:207] Current items: (
"<TableDisplay: 0x5d41cc0>"
)
2010-10-13 02:12:49.020 Remix2[17037:207] didPushItem: <WebDisplay: 0x591a590>
2010-10-13 02:12:49.021 Remix2[17037:207] Current items: (
"<TableDisplay: 0x5d41cc0>",
"<WebDisplay: 0x591a590>"
)
2010-10-13 02:12:49.023 Remix2[17037:207] Selected story: <WebDisplay: 0x591a590>
2010-10-13 02:12:59.498 Remix2[17037:207] didPopItem: <WebDisplay: 0x591a590>
2010-10-13 02:12:59.499 Remix2[17037:207] Current items: (
)
You always have to call [super awakeFromNib] when your subclass implements that method, per the documentation for -awakeFromNib:
You must call the super implementation of awakeFromNib to give parent classes the opportunity to perform any additional initialization they require
Importantly, however, ...
I don't understand why you have to actually manage your own navigation bar. If you subclass UINavigationBar and only override certain drawing or layout methods such as -drawRect:, -layoutSubviews, etc., then all of the logic behind managing the navigation bar in a navigation controller will just fall back on the original UINaviationBar class.
I've had to do extensive view customization for almost every major UIKit class, but I always left the complicated logic to the original classes, overriding only drawing methods to customize the look and feel.
Incidentally, it's actually much easier to skin an entire app without subclassing at all if all you're doing is using custom image assets. By setting a layer's contents property, you can either customize the look and feel of a UIView-based class on an as-needed basis or throughout your entire app:
#import <QuartzCore/QuartzCore.h>
...
- (void)viewDidLoad
{
[super viewDidLoad];
UIImage * navigationBarContents = [UIImage imageNamed:#"navigation-bar"];
self.navigationController.navigationBar.layer.contents =
(id)navigationBarContents.CGImage;
}
You can set the contents for any class that inherits from UIView: navigation bars, toolbars, buttons, etc. It's a lot easier to manage this way without having to subclass at all.
This appears to be a bug in the implementation of -[UINavigationBar items]
When called from inside the -navigationBar:didPopItem: delegate method, it will omit the last object. You can check this by calling [navigationBar valueForKey:#"_itemStack"] to retrieve the underlying array and see that the expected items are still there.
Adding a dispatch_async inside -navigationBar:didPopItem:method successfully works around the issue in my app.