I am having problems with getting the datasource or delegate methods to execute.
I am using a Paging View in my MainViewController and it pages just fine, but when it comes to the tableview is blank and when I put a breakpoint where the datasource methods are, it never gets called.
MainViewController to Load the View
if ((NSNull *)controller2 == [NSNull null])
{
if(page == 2)
{
controller2 = [[requestDetailThreeViewController alloc] initWithRequestNumber:[request objectForKey:#"RequestID"]];
[viewControllers replaceObjectAtIndex:page withObject:controller2];
CGRect frame = scrollView.frame;
frame.origin.x = frame.size.width * 2;
frame.origin.y = 0;
controller2.view.frame = frame;
[scrollView addSubview:controller2.view];
}
}
The TableViewController (requestDetailThreeViewController)
- (void)viewDidLoad
{
[super viewDidLoad];
[History fullHistoryWithBlock:^(NSArray *netMessages, NSError *error) {
if (error) {
[[[UIAlertView alloc] initWithTitle:NSLocalizedString(#"Error", nil) message: [error localizedDescription] delegate:nil cancelButtonTitle:nil otherButtonTitles:NSLocalizedString(#"OK", nil), nil] show];
} else {
NSLog(#"Number of Historical Entries: %d", [netMessages count]);
self.historyFromNet = [NSMutableArray arrayWithArray:netMessages];
}
} forID:requestNum];
}
- (id) initWithRequestNumber:(NSString *)requestID
{
if (self = [super initWithNibName:#"View" bundle:nil])
{
self.requestNum = requestID;
}
return self;
}
(Apologize for the spacing on the 2nd block of code, hard time getting it into code mode.
It executes these two methods, but it doesn't execute the datasource methods I also have in the class.
In the XIB file I have the owner of the xib set to the requestDetailThreeViewController
The tableView is set to datasource/delegate and view
If I set the tableview to hidden in the ViewDidLoad, it does disappear.
I just can't get it to execute the methods to populate the table.
Update:
Some more information-
The View XIB only has a TableView in it, no controllers.
Thanks!
Alan
You are adding a child view controller so you will need to use the UIViewController containment methods.
Something like:
controller2 = [[requestDetailThreeViewController alloc] initWithRequestNumber:[request objectForKey:#"RequestID"]];
[viewControllers replaceObjectAtIndex:page withObject:controller2];
[self addChildViewController:controller2];
CGRect frame = scrollView.frame;
frame.origin.x = frame.size.width * 2;
frame.origin.y = 0;
controller2.view.frame = frame;
[scrollView addSubview:controller2.view];
[controller didMoveToParentViewController:self];
}
Also consider using a UIPageViewController for a paging view rather than doing it manually via a scroll view
You can try to set self.tableView.delegate = self in -(void)viewDidLoad
that is
- (void)viewDidLoad
{
[super viewDidLoad];
self.tableView.delegate = self;
}
I am making a quiz app for chemistry reactions. The app gives the user a question, and the user types in the reactants and products in two separate textfields.
I have a data class, which contains all the possible quiz questions. Then, based on specific parameters, the data class selects a certain amount of questions from the pool of possible questions and shuffles them into an array, quizQuestions.
I also have a view controller, quizController. For each question, a new instance of quizController is loaded. The vc needs the data to know which question to display, what the correct answer is, etc.
This is my original solution to communicate between the data and the vc's.
I create an instance of the data class, data.
I create vc1 for the first question, and set data as a property of vc1, and set its tag as 1, so that it loads the 1st question from the data.
After the user answers the first question, I create a new view controller, vc2, in a method of vc1, make the tag 1 more than the last vc's so that the second question loads, and pass data from vc1's property to vc2's.
And then I repeat for the other questions.
However, this is not very good design, and I am looking for a better solution. I don't think I can use a class method because the data is supposed to contain a random set of questions. Below I have the code for the data class.
// the data class as it is now, designed for instance methods
- (id)init {
self = [super init];
if (self) {
//Questions of the same type belong to a "ROW" (Reaction of Week)
//individual questions
// Items in array: (1)Question, (2)Reactants, (3)Products, (4)Elements for keyboard
NSArray *R1Q1 = [[NSArray alloc] initWithObjects:#"Methanol is burned completely in air", #"2CH₃OH(l) + 3O₂(g)", #"2CO₂(g) + 4H₂O", #"C,H,O", nil];
NSArray *R1Q2 = [[NSArray alloc] initWithObjects:#"Ammonia is burned in excess oxygen gas", #"4NH₃(g) + 7H₂O(l)", #"4NO₂(g) + 6H₂O(l)", #"N,H,O", nil];
NSArray *R1Q3 = [[NSArray alloc] initWithObjects:#"Hydrogen sulfide gas is burned in excess oxygen gas", #"2H₂S(g) + 3O₂(g)", #"CO₂(g) + 2SO₂(g)", #"H,S,O", nil];
NSArray *R2Q1 = [[NSArray alloc] initWithObjects:#"Solid potassium is added to a flask of oxygen gas", #"K(s) + O₂(g)", #"KO₂(s)", #"K,O", nil];
NSArray *R2Q2 = [[NSArray alloc] initWithObjects:#"Sodium metal is dropped into a flask of pure water", #"2Na(s) + H₂O(l)", #"2Na⁺(aq) + 2OH⁻(aq) + H₂(g)", #"Na,H,O", nil];
NSArray *R2Q3 = [[NSArray alloc] initWithObjects:#"A piece of lithium is heated strongly in oxygen", #"4Li(s) + O₂(g)", #"2Li₂O(s)", #"Li,O", nil];
NSArray *R3Q1 = [[NSArray alloc] initWithObjects:#"Solutions of potassium chloride and silver nitrate are mixed", #"Ag⁺(aq) + Cl⁻(aq)", #"AgCl(s)", #"K,Cl,Ag,N,O", nil];
NSArray *R3Q2 = [[NSArray alloc] initWithObjects:#"Solutions of iron(III) nitrate and sodium hydroxide are mixed", #"Fe³⁺(aq) + 3OH⁻(aq)", #"Fe(OH)₃(s)", #"Fe,N,O,Na,H", nil];
NSArray *R3Q3 = [[NSArray alloc] initWithObjects:#"Solutions of nickel iodide and barium hydroxide are mixed", #"Ni²⁺(aq) + 2OH⁻(aq)", #"Ni(OH)₂(s)", #"Ni,I,Ba,OH", nil];
// add rest
//organize questions into groups
row1 = [[NSArray alloc] initWithObjects:R1Q1, R1Q2, R1Q3, nil];
row2 = [[NSArray alloc] initWithObjects:R2Q1, R2Q2, R2Q3, nil];
row3 = [[NSArray alloc] initWithObjects:R3Q1, R3Q2, R3Q3, nil];
//add rest
// array containing all questions
allRows = [[NSMutableArray alloc] initWithObjects:row1, row2, row3, nil];
//in a real situation, needs to be given to class dynamically
self.maxRowNumber = 3;
self.questionsPerRow = 2;
}
return self;
}
- (void)selectQuestions {
self.quizQuestions = [[NSMutableArray alloc] init];
for (int j = 0; j<self.maxRowNumber; j++) {
//shuffle each row
NSMutableArray *row = [NSMutableArray arrayWithArray:[allRows objectAtIndex:j]];
[row shuffle];
//add questions from each row
for (int k = 0; k<self.questionsPerRow; k++)
[quizQuestions addObject:[row objectAtIndex:k]];
}
[quizQuestions shuffle];
}
View Controller code excerpts
# pragma mark Cell Setup
//1st cell in tableview
- (void) setUpEquationCell: (UITableView *) tableView {
equationCell = (EquationCell *) [tableView dequeueReusableCellWithIdentifier:#"equationCell"];
if (equationCell == nil) {
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"EquationCell" owner:self options:nil];
equationCell = (EquationCell*) [nib objectAtIndex:0];
[equationCell.leftButton addTarget:self action:#selector(addDissociateCell) forControlEvents:UIControlEventTouchUpInside];
[equationCell.rightButton addTarget:self action:#selector(addBalanceCell) forControlEvents:UIControlEventTouchUpInside];
}
}
- (void) setUpBalanceCell: (UITableView *) tableView {
//2nd cell in tableview
balanceCell = (BalanceCell *) [tableView dequeueReusableCellWithIdentifier:#"balanceCell"];
if (balanceCell == nil) {
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"BalanceCell" owner:self options:nil];
balanceCell = (BalanceCell*) [nib objectAtIndex:0];
// stores data from equation cell into model
for (FormulaLabel *label in equationCell.leftView.equationOrder)
[leftData.equation addObject:label.text];
for (FormulaLabel *label in equationCell.rightView.equationOrder)
[rightData.equation addObject:label.text];
[leftData setUpBalancedEquation];
[rightData setUpBalancedEquation];
[self setUpView:balanceCell.leftView fromArray:leftData.equation toArray:leftBalanceItems];
[self setUpView:balanceCell.rightView fromArray:rightData.equation toArray:rightBalanceItems];
[self addBalanceTapMethodInArray:leftBalanceItems Data:leftData];
[self addBalanceTapMethodInArray:rightBalanceItems Data:rightData];
}
}
- (void) setUpDissociateCell: (UITableView *) tableView {
dissCell = (DissociateCell *) [tableView dequeueReusableCellWithIdentifier:#"dissCell"];
if (dissCell == nil) {
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"DissociateCell" owner:self options:nil];
dissCell = (DissociateCell*) [nib objectAtIndex:0];
leftData.disEquation = [[NSMutableArray alloc] init];
rightData.disEquation = [[NSMutableArray alloc] init];
// stores data from equation cell into model
for (FormulaLabel *label in equationCell.leftView.equationOrder)
[leftData.disEquation addObject:label.text];
for (FormulaLabel *label in equationCell.rightView.equationOrder)
[rightData.disEquation addObject:label.text];
[self setUpView:dissCell.leftView fromArray:leftData.disEquation toArray:leftDisItems];
[self setUpView:dissCell.rightView fromArray:rightData.disEquation toArray:rightDisItems];
[self addDissTapToArray:leftDisItems fromData:leftData inView:dissCell.leftView];
[self addDissTapToArray:rightDisItems fromData:rightData inView:dissCell.rightView];
[dissCell.dissociateButton addTarget:self action:#selector(dissociate) forControlEvents:UIControlEventTouchUpInside];
}
[dissCell.rightButton addTarget:self action:#selector(addBalanceCell) forControlEvents:UIControlEventTouchUpInside];
}
- (void)addDissociateCell {
[cellOrder addObject:#"dissociateCell"];
[table reloadData];
NSIndexPath *myIndexPath = [NSIndexPath indexPathForRow:0 inSection:([cellOrder count]-1)];
[table scrollToRowAtIndexPath:myIndexPath atScrollPosition:UITableViewScrollPositionTop animated:YES];
}
- (void) addDissTapToArray:(NSMutableArray*)viewOrder fromData:(EquationData*)data inView:(UIView*)view {
NSString *leftOrRight;
if (view == dissCell.leftView)
leftOrRight = #"left";
else
leftOrRight = #"right";
for (int j=0; j < [viewOrder count]; j++) {
if (j%2==0) {
UIView *formulaView = [viewOrder objectAtIndex:j];
//dissociate method
FalseTarget *target = [[FalseTarget alloc] initWithVC:self leftOrRightView:leftOrRight];
UITapGestureRecognizer* tap = [[UITapGestureRecognizer alloc] initWithTarget:target action:#selector(dissTap:)];
[formulaView addGestureRecognizer:tap];
// cancelling method
FalseTarget *target2 = [[FalseTarget alloc] initWithVC:self Data:data ViewList:viewOrder view:view];
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:target2 action:#selector(dissLongTap:)];
[formulaView addGestureRecognizer:longPress];
}
}
}
- (void)addCompoundToLabel:(UIGestureRecognizer *)recognizer leftOrRight:(NSString*)leftRight{
if( [recognizer state] == UIGestureRecognizerStateEnded ) {
FormulaLabel* label = (FormulaLabel*)[recognizer view];
dissIndex = label.tag;
dissCell.unDissociated.text = label.text;
currentDissCellView = leftRight;
}
}
- (void)dissociate {
EquationData *data;
NSMutableArray *viewOrder;
UIView *view;
if ([currentDissCellView isEqualToString:#"left"]) {
data = leftData;
viewOrder = leftDisItems;
view = dissCell.leftView;
}
else {
data = rightData;
viewOrder = rightDisItems;
view = dissCell.rightView;
}
FormulaLabel *c1 = [dissCell.leftTextField.equationOrder objectAtIndex:0];
FormulaLabel *c2 = [dissCell.rightTextField.equationOrder objectAtIndex:0];
[data updateDisEquationAtIndex:dissIndex withCompound1:c1.text Compound2:c2.text];
for (UIView *view in viewOrder)
[view removeFromSuperview];
[viewOrder removeAllObjects];
[self setUpView:view fromArray:data.disEquation toArray:viewOrder];
[self addDissTapToArray:viewOrder fromData:data inView:view];
}
- (void) cancelIons:(id)sender fromData:(EquationData *)data inView:(UIView *)view withViewList:(NSMutableArray *)viewlist {
if( [sender state] == UIGestureRecognizerStateEnded ) {
FormulaLabel* label = (FormulaLabel*)[sender view];
int index = label.tag;
[data.disEquation removeObjectAtIndex:index];
for (UIView *formulaView in viewlist)
[formulaView removeFromSuperview];
[viewlist removeAllObjects];
[self setUpView:view fromArray:data.disEquation toArray:viewlist];
[self addDissTapToArray:viewlist fromData:data inView:view];
}
}
- (void)addBalanceCell {
[cellOrder addObject:#"balanceCell"];
[table reloadData];
NSIndexPath *myIndexPath = [NSIndexPath indexPathForRow:0 inSection:([cellOrder count]-1)];
[table scrollToRowAtIndexPath:myIndexPath atScrollPosition:UITableViewScrollPositionTop animated:YES];
leftBalanceItems = [[NSMutableArray alloc] init];
rightBalanceItems = [[NSMutableArray alloc] init];
}
- (void) addBalanceTapMethodInArray:(NSMutableArray *)balanceItems Data:(EquationData *)data {
FalseTarget *target = [[FalseTarget alloc] initWithVC:self Data:data ViewList:balanceItems view:nil];
for (UIView *view in balanceItems) {
UITapGestureRecognizer* tap = [[UITapGestureRecognizer alloc] initWithTarget:target action:#selector(tap:)];
[view addGestureRecognizer:tap];
}
}
- (void)updateBalanceLabelofSender:(UIGestureRecognizer*)sender fromData:(EquationData *)data inArray:(NSMutableArray *)balanceItems {
FormulaLabel* label = (FormulaLabel*)[sender view];
int oldWidth = label.frame.size.width;
label.text = [data updateBalancedatIndex:label.tag];
[label sizeToFit];
int newWidth = label.frame.size.width;
int difference = newWidth - oldWidth;
int labelIndex = label.tag * 2;
for (int j = 0; j<[balanceItems count]; j++) {
// adjusts coordinate of all views to the right of tapped item
if (j > labelIndex){
UIView *item = [balanceItems objectAtIndex:j];
item.frame = CGRectMake(item.frame.origin.x + difference, item.frame.origin.y, item.frame.size.width, item.frame.size.height);
}
}
}
- (void)setUpView:(UIView *)view fromArray:(NSMutableArray *)equationData toArray:(NSMutableArray *)balanceItems {
int labelCount = 0; //label #
int startingPoint = 5; //x vaiue where first label starts
for (NSString *equationText in equationData) {
//add text
FormulaLabel *tempLabel = [[FormulaLabel alloc] initWithFrame:CGRectMake(startingPoint, 2, 10, 22)];
tempLabel.text = equationText;
[tempLabel sizeToFit];
[view addSubview:tempLabel];
tempLabel.tag = labelCount;
[balanceItems addObject:tempLabel];
//set location of '+'
startingPoint = tempLabel.frame.origin.x + tempLabel.frame.size.width + 3;
if (labelCount != [equationData count]-1) { //not the last label
UILabel *plus = [[[UILabel alloc] initWithFrame:CGRectMake(startingPoint, 5, 10, 10)]autorelease];
plus.text = #"+";
plus.font = [UIFont systemFontOfSize:13];
[plus sizeToFit];
[view addSubview:plus];
startingPoint = plus.frame.origin.x + plus.frame.size.width + 3;
[balanceItems addObject:plus];
}
labelCount ++;
[tempLabel release];
}
}
Why can't you use one view controller class with a question-property where you overload the property's setter method to update the UI to the new data:
in QuestionViewController.h file:
#property (retain, nonatomic) Question* myQuestionData;
in QuestionViewController.m
-(void) setMyQuestionData:(Question*)newData {
[myQuestionData autorelease];
myQuestionData = [newData retain];
[self updateUIElements];
}
I wouldn't do like that, because you are forcing the UIViewController to know about the data model (while making it it's property). What I would do, would be a class and using class methods (and not object methods) would create the data source. You would still have to hold the data in the UIViewController somehow, but I think a NSArray or a NSDictionary would be good enough:
-(void)viewDidLoad{
[superViewDidLoad];
myArray = [MyModel createDataSourceForTag:myTag];
}
I guess here you should go with Model structure.
1. Model: Model represents to entity. Here in your case, there i can create two entities Round, Question
#interface Round: NSObject {
NSUInteger *roundId; // 1, 2 = if it is required to check then this mi
NSArray *questions; // Array that contains objects for Question entity
}
#interface Question:NSObject {
NSString *questionText;
NSString *options1Text;
NSString *options2Text;
NSString *options3Text;
}
#interface DataManager:NSObject {
NSArray *rounds; // Array that contains object for Round entity
}
+(void)sharedInstance;
2. DataManger: DataManager will manage your entity objects. This data manager will be an sharedInstance class. So while initializing manager, entities will be created and data will be inserted.
3. ViewController: Now in view controller you can directly use sharedInstace, like this:
[[DataManager sharedInstance] rounds]
You can easily get code for creating sharedInstance class.
Now you can use this rounds anywhere in the entire application.
So it will be quiet easy to access. For example, if you require 1st round 2nd question 3rd option then, write code for same way
Round 1
Round *r = [[[DataManager sharedInstance] rounds] objectAtIndex:0];
Question 2
Question *q = [[r questions] objectAtIndex:1];
Question Text and Option 3
NSLog(#"questionText : %# 3rd Option: %#", q.questionText, q.option3Text)
Enjoy Coding :)
I am new to trying to create a book app adapting the page-based application of the new xcode just using the single view app, because it is quite confusing learning the template.
i found this code and i am trying to replace the HTML content of this work to UIImageView but i failed.
- (void) createContentPages
{
NSMutableArray *pageStrings = [[NSMutableArray alloc] init];
for (int i = 1; i < 11; i++)
{
NSString *contentString = [[NSString alloc]
initWithFormat:#"<html><head></head><body><h1>Chapter %d</h1><p>This is the page %d of content displayed using UIPageViewController in iOS 5.</p></body></html>", i, i];
[pageStrings addObject:contentString];
}
pageContent = [[NSArray alloc] initWithArray:pageStrings];
}
what i am trying to is to display different images per page.
here is what i did. (i know it is so wrong i just tried it)
- (void) createContentPages
{
NSMutableArray *pageStrings = [[NSMutableArray alloc] init];
for (int i = 1; i < 11; i++)
{
NSArray *photos = [[NSArray arrayWithObjects:
[UIImage imageNamed:#"p1.png"],
[UIImage imageNamed:#"p2.png"],
[UIImage imageNamed:#"p3.png"],
[UIImage imageNamed:#"p4.png"],
nil];
[pageStrings addObject:photos];
}
pageContent = [[NSArray alloc] initWithArray:pageStrings];
}
and it has UIWebView in each page. is it possible that if i replace it with UIImageView it will run?
Here's the rest of the code:
- (void)viewDidLoad
{
[super viewDidLoad];
[self createContentPages];
NSDictionary *options =
[NSDictionary dictionaryWithObject:
[NSNumber numberWithInteger:UIPageViewControllerSpineLocationMin]
forKey: UIPageViewControllerOptionSpineLocationKey];
self.pageController = [[UIPageViewController alloc]
initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl
navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal
options: options];
pageController.dataSource = self;
[[pageController view] setFrame:[[self view] bounds]];
contentViewController *initialViewController =
[self viewControllerAtIndex:0];
NSArray *viewControllers =
[NSArray arrayWithObject:initialViewController];
[pageController setViewControllers:viewControllers
direction:UIPageViewControllerNavigationDirectionForward
animated:NO
completion:nil];
[self addChildViewController:pageController];
[[self view] addSubview:[pageController view]];
[pageController didMoveToParentViewController:self];
}
- (contentViewController *)viewControllerAtIndex:(NSUInteger)index
{
// Return the data view controller for the given index.
if (([self.pageContent count] == 0) ||
(index >= [self.pageContent count])) {
return nil;
}
// Create a new view controller and pass suitable data.
contentViewController *dataViewController =
[[contentViewController alloc]
initWithNibName:#"contentViewController"
bundle:nil];
dataViewController.dataObject =
[self.pageContent objectAtIndex:index];
return dataViewController;
}
- (NSUInteger)indexOfViewController:(contentViewController *)viewController
{
return [self.pageContent indexOfObject:viewController.dataObject];
}
- (UIViewController *)pageViewController:
(UIPageViewController *)pageViewController viewControllerBeforeViewController:
(UIViewController *)viewController
{
NSUInteger index = [self indexOfViewController:
(contentViewController *)viewController];
if ((index == 0) || (index == NSNotFound)) {
return nil;
}
index--;
return [self viewControllerAtIndex:index];
}
- (UIViewController *)pageViewController:
(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
{
NSUInteger index = [self indexOfViewController:
(contentViewController *)viewController];
if (index == NSNotFound) {
return nil;
}
index++;
if (index == [self.pageContent count]) {
return nil;
}
return [self viewControllerAtIndex:index];
}
on subclass
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[webView loadHTMLString:dataObject
baseURL:[NSURL URLWithString:#""]];
}
All time you may use the pictures inside HTML page using the HTML tag <IMG>. So, no the reason to use UIImageView.
Use your createContentPages() method with this one small change (UIImage alone don't represent anything you can put on a "view" Instead you need to use a UIImageView which holds UIImages):
- (void) createContentPages
{
NSMutableArray *pageStrings = [[NSMutableArray alloc] init];
for (int i = 1; i < 11; i++)
{
NSArray *photos = [[NSArray arrayWithObjects:
[[[UIImageView alloc] initWithImage:[UIImage imageNamed:#"p1.png"] autorelease],
[[[UIImageView alloc] initWithImage:[UIImage imageNamed:#"p2.png"] autorelease],
[[[UIImageView alloc] initWithImage:[UIImage imageNamed:#"p3.png"] autorelease],
[[[UIImageView alloc] initWithImage:[UIImage imageNamed:#"p4.png"] autorelease],
nil];
[pageStrings addObject:photos];
}
pageContent = [[NSArray alloc] initWithArray:pageStrings];
}
You can use the code from the main controller (the big block of code that you posted).
The only changes you'll need to make are in what you're calling the "subclass." (really it's the UIPageViewController that handles showing the actual pages).
In that UIPageViewController remove the "webView" (UIWebView). This is probably done in the .xib file (doesn't look like it's added in the code). Then make, viewWillAppear in the UIPageViewController look like this:
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
self.view = dataObject;
}
That should do the trick. Basically, we are no longer using the UIWebView to show HTML data, and instead just adding the dataObject (a UIImageView) as a subview of the UIPageViewController. Hope this helps!
In my viewcontroller I use Maps and I load a list of pins.
When I move the map or zoom in or out it, my app crashes and displays this error:
[GMMGeoTileImageData isEqualToString:]: unrecognized selector sent to instance 0x862d3b0
This is my code of the view controller:
- (void)viewDidLoad
{
statoAnn = [[NSMutableString alloc] initWithFormat:#"false"];
//bottone annulla per tornare indietro
UIBarButtonItem *annullaButton = [[[UIBarButtonItem alloc] initWithTitle:#"Annulla" style:UIBarButtonItemStylePlain target:self action:#selector(backView)] autorelease];
self.navigationItem.leftBarButtonItem = annullaButton;
//inizializzo la mappa
mapView = [[MKMapView alloc] initWithFrame:CGRectMake(0, 0, 320, 416)];
mapView.delegate = self;
mapView.mapType = MKMapTypeStandard;
[self.view addSubview:mapView];
[self setGmaps:arrData];
[super viewDidLoad];
}
/** inizializzo l'annotation del poi mappa **/
- (void) setGmaps:(NSMutableArray*)inputData {
// setto la lat e lng
CLLocationDegrees latitude;
CLLocationDegrees longitude;
CLLocationCoordinate2D poiLocation;
arrAnn = [[NSMutableArray alloc] init];
for(int i=0; i<[inputData count]; i++) {
//ricavo la lat e lng del pin
latitude = [[[inputData objectAtIndex:i] objectForKey:#"latitude"] doubleValue];
longitude = [[[inputData objectAtIndex:i] objectForKey:#"longitude"] doubleValue];
// setto la location del poi
poiLocation.latitude = latitude;
poiLocation.longitude = longitude;
//[[[CLLocation alloc] initWithLatitude:latitude longitude:longitude] autorelease];
//setto il pin
Annotation *ann = [[Annotation alloc] initWithCoordinate:poiLocation];
ann.title = [[inputData objectAtIndex:i] objectForKey:#"label"];
[arrAnn addObject:ann];
[ann release];
}
if (nil != self.arrAnn) {
[self.mapView addAnnotations:arrAnn];
//self.ann = nil;
self.arrAnn = nil;
}
}
/** setto il pin nella mappa ***/
- (void)setCurrentLocation:(CLLocation *)location {
MKCoordinateRegion region = {{0.0f, 0.0f}, {0.0f, 0.0f}};
region.center = location.coordinate;
region.span.longitudeDelta = 0.1f;
region.span.latitudeDelta = 0.1f;
[self.mapView setRegion:region animated:YES];
[self.mapView regionThatFits:region];
}
- (MKAnnotationView *)mapView:(MKMapView *)mapViewTemp viewForAnnotation:(id <MKAnnotation>)annotation {
MKPinAnnotationView *view = nil; // return nil for the current user location
view = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:#"identifier"];
if (nil == view) {
view = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:#"identifier"] autorelease];
view.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
}
[view setPinColor:MKPinAnnotationColorPurple];
[view setCanShowCallout:YES];
[view setAnimatesDrop:YES];
if (![statoAnn isEqualToString:#"true"]) {
CLLocation *location = [[CLLocation alloc] initWithLatitude:annotation.coordinate.latitude
longitude:annotation.coordinate.longitude];
[self setCurrentLocation:location];
statoAnn = [NSMutableString stringWithFormat:#"true"];
}
return view;
}
In viewForAnnotation, this line:
statoAnn = [NSMutableString stringWithFormat:#"true"];
sets statoAnn to an autoreleased string.
When the method exits, release is called on statoAnn and it no longer owns the memory it was pointing to. When the method is called again when you zoom or move the map, the memory that statoAnn was pointing to is now used by something else (GMMGeoTileImageData in this case). That object is not an NSString and doesn't have an isEqualToString: method and you get the error you are seeing.
To fix this, set statoAnn so the value is retained like you are doing in viewDidLoad. For example, you could change it to:
statoAnn = [[NSMutableString alloc] initWithFormat:#"true"];
You could also declare statoAnn as a property (#property (nonatomic, copy) NSString *statoAnn) and just set it using self.statoAnn = #"true";. The property setter will do the retaining for you.
However, you don't need to use a string to hold a "true" and "false" value. It's much easier and efficient to use a plain BOOL and you won't have to worry about retain/release since it's a primitive type and not an object.
The other thing is that viewForAnnotation is not the right place to be setting the map view's region in the first place. You can do that in viewDidLoad after the annotations are added.
Another thing: At the top of viewForAnnotation, you have the comment "return nil for the current user location" but that code doesn't do that. It just initializes the view to nil. To actually do what the comment says, you need this:
MKPinAnnotationView *view = nil;
// return nil for the current user location...
if ([annotation isKindOfClass:[MKUserLocation class]])
return nil;
Finally, if the dequeueReusableAnnotationViewWithIdentifier does return a view (if view != nil), you need to set view.annotation to the current annotation since the re-used view may have been for a different annotation.
I am trying to remove all the annotations of a map. The class that contains the MKMapView implements the MKMapViewDelegate. I am calling the remove all annotations method when a button (displayed in a modal view) is clicked. I am using the next code to remove all the annotations.
- (void)removeAllAnnotations {
NSMutableArray *annotationsToRemove = [NSMutableArray arrayWithCapacity:[self.mapView.annotations count]];
for (int i = 0; i < [self.mapView.annotations count]; i++) {
if ([[self.mapView.annotations objectAtIndex:i] isKindOfClass:[AddressAnnotation class]]) {
[annotationsToRemove addObject:[self.mapView.annotations objectAtIndex:i]];
}
}
[self.mapView removeAnnotations:annotationsToRemove];
}
The code works right but after calling the method, and when I try to add new annotations to the empty map, the class does not call to the viewForAnnotations method and the annotations do not drop down and do not show a disclosure button into the annotation view. Why is this happening?
Thanks for reading.
Edited:
The annotations are shown but with out calling the view for annotation method (with out dropping down and with out including a disclosure button into the annotation view). Here is the method that I use to add the annotations and the viewForAnnotation method.
- (void)loadAnnotations:(NSString *)type {
NSString *path = [[NSBundle mainBundle] pathForResource:#"PlacesInformation" ofType:#"plist"];
NSMutableArray *tmpArray = [[NSMutableArray alloc] initWithContentsOfFile:path];
for (int i = 0; i < tmpArray.count; i++) {
// Breaks the string down even further to latitude and longitude fields.
NSString *coordinateString = [[tmpArray objectAtIndex:i] objectForKey:#"coordinates"];
NSString *option = [[tmpArray objectAtIndex:i] objectForKey:#"type"];
if ([option isEqualToString:type]) {
CLLocationCoordinate2D currentCoordinate = [self stringToCoordinate:coordinateString];
AddressAnnotation *annotation = [[[AddressAnnotation alloc] initWithCoordinate:currentCoordinate] autorelease];
[self.mapView addAnnotation:annotation];
}
}
}
- (MKAnnotationView *)mapView:(MKMapView *)theMapView viewForAnnotation:(id <MKAnnotation>)annotation {
// If it's the user location, just return nil.
if ([annotation isKindOfClass:[MKUserLocation class]])
return nil;
else { // Handles the other annotations.
// Try to dequeue an existing pin view first.
static NSString *AnnotationIdentifier = #"AnnotationIdentifier";
MKPinAnnotationView *pinView = (MKPinAnnotationView *)[self.mapView dequeueReusableAnnotationViewWithIdentifier:AnnotationIdentifier];
if (!pinView) {
// If an existing pin view was not available, creates one.
MKPinAnnotationView *customPinView = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:AnnotationIdentifier] autorelease];
customPinView.animatesDrop = YES;
customPinView.canShowCallout = YES;
// Adds a detail disclosure button.
UIButton *rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
[rightButton addTarget:self action:#selector(showDetails:) forControlEvents:UIControlEventTouchUpInside];
customPinView.rightCalloutAccessoryView = rightButton;
return customPinView;
} else
pinView.annotation = annotation;
}
return nil;
}
In viewForAnnotation, in the case where you are reusing a view, you are currently returning nil.
This else part:
} else
pinView.annotation = annotation;
Should probably be:
} else {
pinView.annotation = annotation;
return pinView;
}