I've been having this issue for a couple of weeks now, and I still have not found an answer. on my MapView I have custom annotations, and when I hit the "reload button" all the information is correct as in the annotation "title, subtitle". but the annotation has changed. the annotations are in a NSMutableArray and I'm sure that the issue i am having revolves around that. here is the code I am using to reload the annotations.
so just prevent any confusion, my custom annotations work just fine when i first load the mapView. But once i hit the reload button, all the annotation's information like "location,title, subtitle" all that is correct, just the actual annotation has changed. Like all the annotations have been switched around.
if anyone can help, it would greatly be appreciated! thanks!
- (IBAction)refreshMap:(id)sender {
NSArray *annotationsOnMap = myMapView.annotations;
[myMapView removeAnnotations:annotationsOnMap];
[locations removeAllObjects];
[citiesArray removeAllObjects];
[self retrieveData];
}
-(void) retrieveData {
userLAT = [NSString stringWithFormat:#"%f", myMapView.userLocation.coordinate.latitude];
userLNG = [NSString stringWithFormat:#"%f", myMapView.userLocation.coordinate.longitude];
NSString *fullPath = [mainUrl stringByAppendingFormat:#"map_json.php?userID=%#&lat=%#&lng=%#",theUserID,userLAT,userLNG];
NSURL * url =[NSURL URLWithString:fullPath];
NSData *data = [NSData dataWithContentsOfURL:url];
json =[NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
citiesArray =[[NSMutableArray alloc]init];
for (int i = 0; i < json.count; i++)
{
//create city object
NSString * eID =[[json objectAtIndex:i] objectForKey:#"userid"];
NSString * eAddress =[[json objectAtIndex:i] objectForKey:#"full_address"];
NSString * eHost =[[json objectAtIndex:i] objectForKey:#"username"];
NSString * eLat =[[json objectAtIndex:i] objectForKey:#"lat"];
NSString * eLong =[[json objectAtIndex:i] objectForKey:#"lng"];
NSString * eName =[[json objectAtIndex:i] objectForKey:#"Restaurant_name"];
NSString * eState = [[json objectAtIndex:i] objectForKey:#"type"];
NSString * annotationPic = [[json objectAtIndex:i] objectForKey:#"Annotation"];
NSString * eventID = [[json objectAtIndex:i] objectForKey:#"id"];
//convert lat and long from strings
float floatLat = [eLat floatValue];
float floatLONG = [eLong floatValue];
City * myCity =[[City alloc] initWithRestaurantID: (NSString *) eID andRestaurantName: (NSString *) eName andRestaurantState: (NSString *) eState andRestaurantAddress: (NSString *) eAddress andRestaurantHost: eHost andRestaurantLat: (NSString *) eLat andRestaurantLong: (NSString *) eLong];
//Add our city object to our cities array
// Do any additional setup after loading the view.
[citiesArray addObject:myCity];
//Annotation
locations =[[NSMutableArray alloc]init];
CLLocationCoordinate2D location;
Annotation * myAnn;
//event1 annotation
myAnn =[[Annotation alloc]init];
location.latitude = floatLat;
location.longitude = floatLONG;
myAnn.coordinate = location;
myAnn.title = eName;
myAnn.subtitle = eHost;
myAnn.type = eState;
myAnn.AnnotationPicture = annotationPic;
myAnn.passEventID = eventID;
myAnn.hotZoneLevel = hotZone;
[locations addObject:myAnn];
[self.myMapView addAnnotations:locations];
}
}
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
if([annotation isKindOfClass:[MKUserLocation class]])
return nil;
static NSString *annotationIdentifier = #"AnnotationIdentifier";
MKAnnotationView *annotationView = (MKAnnotationView *) [self.myMapView
dequeueReusableAnnotationViewWithIdentifier:annotationIdentifier];
if (!annotationView)
{
annotationView = [[MKAnnotationView alloc]
initWithAnnotation:annotation
reuseIdentifier:annotationIdentifier];
NSString *restaurant_Icon = ((Annotation *)annotation).AnnotationPicture;
NSString *restaurant_Callout = [NSString stringWithFormat:#"mini.%#",restaurant_Icon];
UIImage *oldImage = [UIImage imageNamed:restaurant_Icon];
UIImage *newImage;
CGSize newSize = CGSizeMake(75, 75);
newImage = [oldImage imageScaledToFitSize:newSize]; // uses MGImageResizeScale
annotationView.image= newImage;
annotationView.canShowCallout = YES;
UIImage *Mini_oldImage = [UIImage imageNamed:event_Callout];
UIImage *Mini_newImage;
CGSize Mini_newSize = CGSizeMake(30,30);
Mini_newImage = [Mini_oldImage imageScaledToFitSize:Mini_newSize]; // uses MGImageResizeScale
UIImageView *finalMini_callOut = [[UIImageView alloc] initWithImage:Mini_newImage];
annotationView.leftCalloutAccessoryView = finalMini_callOut;
UIButton* rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
annotationView.rightCalloutAccessoryView = rightButton;
}
else
{
annotationView.annotation = annotation;
}
return annotationView;
}
If nothing else, you're setting the icon and the callout based upon the annotation, but only doing that in viewForAnnotation if the annotation was not dequeued. You really want to do any annotation-specific customization outside of that if block, in case an annotation view is reused.
Unrelated to your reported issue, there are a few other observations:
You probably should be doing retrieveData asynchronously so you don't tie up the main thread with your data retrieval/parsing. Go ahead and dispatch the adding of the entry to your array and adding the annotation to the map in the main queue, but the network stuff and should definitely be done asynchronously.
You probably should check to make sure data is not nil (e.g. no network connection or some other network error) because JSONObjectWithData will crash if you pass it a nil value.
Your use of locations seems unnecessary because you're resetting it for every entry in your JSON. You could either (a) retire locations entirely and just add the myAnn object to your map's annotations; or (b) initialize locations before the for loop. But it's probably misleading to maintain this ivar, but only populate it with the last annotation.
Related
I am fairly new to Objective-C and I find there are a lot of tutorials for iOS and UITableView but almost none for OS X Apps via NSTableView. I have built a method to retrieve my data but I get an error on the last line:
"Property tableView not found on object type ProductsViewController".
I do not know the correct way to reload my data into my table or if I even need to use an NSTableView for this specific instance? Is there a better way to display my data than using NSTableView?
#import "ProductsViewController.h"
#import "Product.h"
#define getDataURL #"http://myurl"
#interface ProductsViewController ()
#end
#implementation ProductsViewController
#synthesize jsonArray, productsArray;
- (void)viewDidLoad {
[super viewDidLoad];
[self retrieveData];
}
-(NSInteger)numberOfRowsInTable:(NSTableView *)tableView{
return productsArray.count;
}
- (void) retrieveData{
NSURL * url = [NSURL URLWithString:getDataURL];
NSData * data = [NSData dataWithContentsOfURL:url];
jsonArray = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
productsArray = [[NSMutableArray alloc] init];
for(int i = 0; i < jsonArray.count; i++){
NSString * pID = [[jsonArray objectAtIndex:i] objectForKey:#"id"];
NSString * pName = [[jsonArray objectAtIndex:i] objectForKey:#"product_name"];
NSString * pPrice = [[jsonArray objectAtIndex:i] objectForKey:#"product_price"];
NSString * pDescription = [[jsonArray objectAtIndex:i] objectForKey:#"product_description"];
NSString * pImage = [[jsonArray objectAtIndex:i] objectForKey:#"product_image"];
NSString * pDownload = [[jsonArray objectAtIndex:i] objectForKey:#"product_download"];
NSString * pVideo = [[jsonArray objectAtIndex:i] objectForKey:#"product_video"];
NSString * pFeatured = [[jsonArray objectAtIndex:i] objectForKey:#"featured"];
[productsArray addObject:[[Product alloc] initWithProduct_Name: pName andProduct_Price:pPrice andProduct_Description:pDescription andProduct_Image:pImage andProduct_Download:pDownload andProduct_Video:pVideo andProduct_Featured:pFeatured andProduct_ID:pID]];
}
[self.tableView reloadData];
}
You need to implement the required delegate methods for the NSTableViewDataSource protocol. Specifically, you need these two:
numberOfRowsInTableView:
tableView:objectValueForTableColumn:row:
The table view will then call these methods for the data it wants.
In addition, there's a great tutorial over at raywenderlich.com about using NSTableViews.
I have an app that shows twitter account feed. So I have ImageView, textLabel and detailLabel for the content of the feed. The problem is that when all the data is loaded, the uiimage doesn't appear. When I click on the cell or scroll up-down, images are set. here is some of my code.
-(void)getImageFromUrl:(NSString*)imageUrl asynchronouslyForImageView:(UIImageView*)imageView andKey:(NSString*)key{
dispatch_async(dispatch_get_global_queue(
DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
NSURL *url = [NSURL URLWithString:imageUrl];
__block NSData *imageData;
dispatch_sync(dispatch_get_global_queue(
DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
imageData =[NSData dataWithContentsOfURL:url];
if(imageData){
[self.imagesDictionary setObject:[UIImage imageWithData:imageData] forKey:key];
dispatch_sync(dispatch_get_main_queue(), ^{
imageView.image = self.imagesDictionary[key];
});
}
});
});
}
- (void)refreshTwitterHomeFeedWithCompletion {
// Request access to the Twitter accounts
ACAccountStore *accountStore = [[ACAccountStore alloc] init];
ACAccountType *accountType = [accountStore accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierTwitter];
[accountStore requestAccessToAccountsWithType:accountType options:nil completion:^(BOOL granted, NSError *error){
if (granted) {
NSArray *accounts = [accountStore accountsWithAccountType:accountType];
// Check if the users has setup at least one Twitter account
if (accounts.count > 0)
{
ACAccount *twitterAccount = [accounts objectAtIndex:0];
NSLog(#"request.account ...%#",twitterAccount.username);
NSURL* url = [NSURL URLWithString:#"https://api.twitter.com/1.1/statuses/home_timeline.json"];
NSDictionary* params = #{#"count" : #"50", #"screen_name" : twitterAccount.username};
SLRequest *request = [SLRequest requestForServiceType:SLServiceTypeTwitter
requestMethod:SLRequestMethodGET
URL:url parameters:params];
request.account = twitterAccount;
[request performRequestWithHandler:^(NSData *responseData,
NSHTTPURLResponse *urlResponse, NSError *error) {
if (error)
{
NSString* errorMessage = [NSString stringWithFormat:#"There was an error reading your Twitter feed. %#",
[error localizedDescription]];
NSLog(#"%#",errorMessage);
}
else
{
NSError *jsonError;
NSArray *responseJSON = [NSJSONSerialization
JSONObjectWithData:responseData
options:NSJSONReadingAllowFragments
error:&jsonError];
if (jsonError)
{
NSString* errorMessage = [NSString stringWithFormat:#"There was an error reading your Twitter feed. %#",
[jsonError localizedDescription]];
NSLog(#"%#",errorMessage);
}
else
{
NSLog(#"Home responseJSON..%#",(NSDictionary*)responseJSON.description);
dispatch_async(dispatch_get_main_queue(), ^{
[self reloadData:responseJSON];
});
}
}
}];
}
}
}];
}
-(void)reloadData:(NSArray*)jsonResponse
{
self.tweets = jsonResponse;
[self.tableView reloadData];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
// Return the number of sections.
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
// Return the number of rows in the section.
return self.tweets.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
SNTwitterCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(!cell)
{
cell = [[SNTwitterCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
NSDictionary *tweetDictionary = self.tweets[indexPath.row];
NSDictionary *user = tweetDictionary[#"user"];
NSString *userName = user[#"name"];
NSString *tweetContaint = tweetDictionary[#"text"];
NSString* imageUrl = [user objectForKey:#"profile_image_url"];
[self getImageFromUrl:imageUrl asynchronouslyForImageView:cell.imageView andKey:userName];
cell.profileImage.image = [UIImage imageNamed:#"images.png"];
NSArray *days = [NSArray arrayWithObjects:#"Mon ", #"Tue ", #"Wed ", #"Thu ", #"Fri ", #"Sat ", #"Sun ", nil];
NSArray *calendarMonths = [NSArray arrayWithObjects:#"Jan", #"Feb", #"Mar",#"Apr", #"May", #"Jun", #"Jul", #"Aug", #"Sep", #"Oct", #"Nov", #"Dec", nil];
NSString *dateStr = [tweetDictionary objectForKey:#"created_at"];
for (NSString *day in days) {
if ([dateStr rangeOfString:day].location == 0) {
dateStr = [dateStr stringByReplacingOccurrencesOfString:day withString:#""];
break;
}
}
NSArray *dateArray = [dateStr componentsSeparatedByString:#" "];
NSArray *hourArray = [[dateArray objectAtIndex:2] componentsSeparatedByString:#":"];
NSDateComponents *components = [[NSDateComponents alloc] init];
NSString *aux = [dateArray objectAtIndex:0];
int month = 0;
for (NSString *m in calendarMonths) {
month++;
if ([m isEqualToString:aux]) {
break;
}
}
components.month = month;
components.day = [[dateArray objectAtIndex:1] intValue];
components.hour = [[hourArray objectAtIndex:0] intValue];
components.minute = [[hourArray objectAtIndex:1] intValue];
components.second = [[hourArray objectAtIndex:2] intValue];
components.year = [[dateArray objectAtIndex:4] intValue];
NSTimeZone *gmt = [NSTimeZone timeZoneForSecondsFromGMT:2];
[components setTimeZone:gmt];
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
[calendar setTimeZone:[NSTimeZone systemTimeZone]];
NSDate *date = [calendar dateFromComponents:components];
NSString *tweetDate = [self getTimeAsString:date];
NSString *tweetValues = [NSString stringWithFormat:#"%# :%#",userName,tweetDate];
cell.textLabel.text = [NSString stringWithFormat:#"%#",tweetValues];
cell.detailTextLabel.text = [NSString stringWithFormat:#"%#",tweetContaint];
[cell.detailTextLabel setFont:[UIFont fontWithName:#"Helvetica" size:20]];
return cell;
}
- (NSString*)getTimeAsString:(NSDate *)lastDate {
NSTimeInterval dateDiff = [[NSDate date] timeIntervalSinceDate:lastDate];
int nrSeconds = dateDiff;//components.second;
int nrMinutes = nrSeconds / 60;
int nrHours = nrSeconds / 3600;
int nrDays = dateDiff / 86400; //components.day;
NSString *time;
if (nrDays > 5){
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateStyle:NSDateFormatterShortStyle];
[dateFormat setTimeStyle:NSDateFormatterNoStyle];
time = [NSString stringWithFormat:#"%#", [dateFormat stringFromDate:lastDate]];
} else {
// days=1-5
if (nrDays > 0) {
if (nrDays == 1) {
time = #"1 day ago";
} else {
time = [NSString stringWithFormat:#"%d days ago", nrDays];
}
} else {
if (nrHours == 0) {
if (nrMinutes < 2) {
time = #"just now";
} else {
time = [NSString stringWithFormat:#"%d minutes ago", nrMinutes];
}
} else { // days=0 hours!=0
if (nrHours == 1) {
time = #"1 hour ago";
} else {
time = [NSString stringWithFormat:#"%d hours ago", nrHours];
}
}
}
}
return [NSString stringWithFormat:NSLocalizedString(#"%#", #"label"), time];
}
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return 100;
}
The fundamental problem is that the standard imageView property of the standard table view cell will automatically resize itself based upon the image that is present when cellForRowAtIndexPath finishes. But since there is no image yet when you first present the table, the cell is laid out as if there's no image. And when you asynchronously update the image view's image, it won't resize the image view.
There are a couple of ways of solving this:
Don't use the default imageView provided by UITableViewCell, but rather define your own custom cell subclass with an IBOutlet to its own UIImageView property. Make sure that this UIImageView has a fixed layout (i.e., it doesn't use the intrinsic size derived from the underlying image).
If you do that, you can asynchronously update the image property for your custom UIImageView outlet, and because the layout was not contingent upon the presence of the image, any asynchronous updates of that image should appear correctly.
When you receive the image, don't just set the image view's image property, but rather reload the whole row associated with that NSIndexPath using reloadRowsAtIndexPaths.
If you do this, the cell will be laid out correctly assuming that you retrieve the image from the cache correctly, and do so before cellForRowAtIndexPath finishes.
Note, if you do this, you will need to fix your getImageFromUrl to actually try to retrieve the image from the cache first (and do this from the main queue, before to dispatch to the background queue), or else you'll end up in an endless loop.
Having said that, there are deeper problems here.
As I mentioned above, you're caching your images, but never using the cache when retrieving the images.
You are asynchronously updating the image view.
You should initialize the image property of the UIImageView before you initiate the new asynchronous fetch, otherwise when a cell is reused, you'll see the old image there until the new image is retrieved.
What if the cell was reused in the intervening period between calling getImageFromUrl and when the asynchronous request finishes? You'll be updating the image view for the wrong cell. (This problem will be more apparent when doing this over a slow connection. Run your code using the network link conditioner to simulate slow connections and you'll see the problem I'm describing.)
What if the user rapidly scrolls down to the 100th row in the table? The network requests for the visible cells will be backlogged behind the other 99 image requests. You could even get timeout errors on slow connections.
There are a bunch of tactical little issues in getImageFromUrl.
Why dispatching synchronously from global queue to another global queue? That's unnecessary. Why dispatching UI update synchronously to main thread? That's inefficient.
Why define imageData as __block outside of the block; just define it within the block and you don't need __block qualifier.
What if you didn't receive a valid UIImage from the network request (e.g. you got a 404 error message); the existing code would crash. There are all sorts of responses the server might provide which are not a valid image, and you really must identify that situation (i.e. make sure that not only was NSData you received not nil, but also that the UIImage that you created from it was not nil, too).
I'd probably use NSCache rather than NSMutableDictionary for the cache. Also, regardless of whether you use NSCache or NSMutableDictionary, you want to make sure that you respond to memory pressure events and empty that cache if needed.
We can go through all of these individual problems, but it's a non-trivial amount of work to fix all of this. I might therefore suggest you consider the UIImageView categories of SDWebImage or AFNetworking. They take care of most of these issues, plus others. It will make your life much, much easier.
Good morning, I am very new to objective-c now I am developing my first app. It's a vehicle tracking app. I received the x-number of lat & long from the json service. Now I displayed a single annotation but I need to display all the annotation points which i received from the service here I search for a whole day to find this but am fails to find displaying x-num of annotations. So kindly advice me by using some sample codes. Thanks in Advance... My code is..
- (void)viewDidLoad
{
[super viewDidLoad];
//MAP VIEW WebService
NSString *urlMapString=[NSString stringWithFormat:#"http://www.logix.com/logix_webservice/map.php?format=json&truckno=%#",nam2];
NSURL *urlMap=[NSURL URLWithString:urlMapString];
NSData *dataMap=[NSData dataWithContentsOfURL:urlMap];
NSError *errorMap;
NSDictionary *jsonMap = [NSJSONSerialization JSONObjectWithData:dataMap options:kNilOptions error:&errorMap]; NSArray *resultsMap = [jsonMap valueForKey:#"posts"];
NSArray *resMap = [resultsMap valueForKey:#"post"];
NSArray *latitudeString=[resMap valueForKey:#"latitude"];
if([resMap count]){
NSString *latOrgstring = [latitudeString objectAtIndex:0];
double latitude=[latOrgstring doubleValue];
NSArray *longitudeString=[resMap valueForKey:#"longitude"];
NSString *longOrgstring = [longitudeString objectAtIndex:0];
double longitude=[longOrgstring doubleValue];
NSString *ignation=[[resMap valueForKey:#"ignition"]objectAtIndex:0];
i=[ignation intValue];
//MAP VIEW Point
MKCoordinateRegion myRegion;
//Center
CLLocationCoordinate2D center;
center.latitude=latitude;
center.longitude=longitude;
//Span
MKCoordinateSpan span;
span.latitudeDelta=0.01f;
span.longitudeDelta=0.01f;
myRegion.center=center;
myRegion.span=span;
//Set our mapView
[MapViewC setRegion:myRegion animated:YES];
//Annotation
//1.create coordinate for use with the annotation
CLLocationCoordinate2D wimbLocation;
wimbLocation.latitude=latitude;
wimbLocation.longitude=longitude;
Annotation * myAnnotation= [Annotation alloc];
CLLocation *someLocation=[[CLLocation alloc]initWithLatitude:latitude longitude:longitude];
CLGeocoder *geocoder = [[CLGeocoder alloc] init];
[geocoder reverseGeocodeLocation:someLocation completionHandler:^(NSArray *placemarks, NSError *error) {
NSDictionary *dictionary = [[placemarks objectAtIndex:0] addressDictionary];
addressOutlet=[dictionary valueForKey:#"Street"];
City=[dictionary valueForKey:#"City"];
State=[dictionary valueForKey:#"State"];
myAnnotation.coordinate=wimbLocation;
if (addressOutlet!=NULL&&City!=NULL)
{
myAnnotation.title=addressOutlet;
myAnnotation.subtitle=[NSString stringWithFormat:#"%#,%#", City, State];
}
else if (addressOutlet==NULL&&City!=NULL)
{
myAnnotation.title=City;
myAnnotation.subtitle=[NSString stringWithFormat:#"%#,%#", City, State];
}
else if (addressOutlet!=NULL&&City==NULL)
{
myAnnotation.title=addressOutlet;
myAnnotation.subtitle=[NSString stringWithFormat:#"%#", State];
}
else if(addressOutlet==NULL&&City==NULL)
{
myAnnotation.title=State;
myAnnotation.subtitle=[NSString stringWithFormat:#"%#",State];
}
[self.MapViewC addAnnotation:myAnnotation];
}];
}
}
Please make an individual class and use by importing .
Now use
-(id)initWithCoordinate:(CLLocationCoordinate2D)c;
and its .m file
-(id)initWithCoordinate:(CLLocationCoordinate2D)c
{
coordinate=c;
}
Now call this class anywhere and call this method and send your location coordinates.
and then add its objects into NSArray.
Now call [YourMapView addAnnotations:arrayOfAnnotations];
You will get it what you want.It works in my case I hope you will find it supportive.
Now add annotations on mapView:
-(MKAnnotationView *) mapView:(MKMapView *)mapV
viewForAnnotation:(id<MKAnnotation>)annotation
{
if ([annotation isKindOfClass:[pinAnnotation class]])
{
static NSString *defaultPinID = #"com.ABC.pin";//Your unique identifier anything
MKAnnotationView *pinView = nil;
if(!pinView)
{
pinView = (MKAnnotationView *)
[self.mapView dequeueReusableAnnotationViewWithIdentifier:defaultPinID];
pinView = [[MKAnnotationView alloc] initWithAnnotation:
annotation reuseIdentifier:defaultPinID] ;
return pinView;
}
static NSString *AnnotationViewID = #"annotationViewID";
MKAnnotationView* pin =
(MKAnnotationView*) [mapV dequeueReusableAnnotationViewWithIdentifier:
AnnotationViewID];
if ( pin == nil ) {
pin = [(MKAnnotationView*) [MKAnnotationView alloc]
initWithAnnotation:annotation reuseIdentifier: AnnotationViewID] ;
pin.canShowCallout = YES;
}
else
{
[pin setAnnotation: annotation];
}
((MKUserLocation *)annotation).title = #"You are here";
return pin;
}
I have this code:
-(void)handleLongPressGesture:(UIGestureRecognizer*)sender {
NSNumber* existingpoints = [[NSNumber alloc]init];
existingpoints =[NSNumber numberWithInt:0];
// This is important if you only want to receive one tap and hold event
if (sender.state == UIGestureRecognizerStateEnded)
{
[self.mapView removeGestureRecognizer:sender];
}
else {
do {
int z = 1;
existingpoints =[NSNumber numberWithInt:z];
// Here we get the CGPoint for the touch and convert it to latitude and longitude coordinates to display on the map
CGPoint point = [sender locationInView:self.mapView];
CLLocationCoordinate2D locCoord = [self.mapView convertPoint:point toCoordinateFromView:self.mapView];
// Then all you have to do is create the annotation and add it to the map
MKPointAnnotation *annotationPoint = [[MKPointAnnotation alloc] init]; annotationPoint.coordinate = locCoord;
NSString *latitude = [[NSString alloc] initWithFormat:#"%f",locCoord.latitude];
NSString *longitude = [[NSString alloc] initWithFormat:#"%f", locCoord.longitude];
annotationPoint.title = #"Event";
annotationPoint.subtitle = [NSString stringWithFormat:#"%# & %#", latitude, longitude];
[mapView addAnnotation:annotationPoint];
[[NSUserDefaults standardUserDefaults]setObject:latitude forKey:#"FolderLatitude"];
[[NSUserDefaults standardUserDefaults]setObject:longitude forKey:#"FolderLongitude"];
} while ([existingpoints intValue] == 0);
}
}
...but the problem is that when I hold, and then drag more than one pin is added. I want to add only one pin. So I tried the do method but it doesn't work. I can't understand, because when I executed the code I turn the value of the NSNumber to 1, and the while says = 0 to run the code.
Please Help!!
Your current code is prone to have quite a number of memory leaks. For example:
NSNumber* existingpoints = [[NSNumber alloc] init];
existingpoints = [NSNumber numberWithInt:0];
Is leaking because you leave the first instance of existingpoints with retain value of 1 and not freeing it anywhere. Unless you're using ARC. You can optimize the above code with just one instruction:
NSNumber* existingpoints = [NSNumber numberWithInt:0];
And retain it if you need to keep it somewhere (but i belive it's not the case).
Analyzing the code, I'd recommend NOT to use existingpoints as an NSNumber. Use an NSInteger instead (which is not an object, just a typedef to long).
Here's my rewritten code:
-(void)handleLongPressGesture:(UIGestureRecognizer*)sender {
NSInteger existingpoints = 0;
// This is important if you only want to receive one tap and hold event
if (sender.state == UIGestureRecognizerStateEnded) {
[self.mapView removeGestureRecognizer:sender];
}
else {
do {
int z = 1;
existingpoints = z;
// Here we get the CGPoint for the touch and convert it to latitude and longitude coordinates to display on the map
CGPoint point = [sender locationInView:self.mapView];
CLLocationCoordinate2D locCoord = [self.mapView convertPoint:point toCoordinateFromView:self.mapView];
// Then all you have to do is create the annotation and add it to the map
MKPointAnnotation *annotationPoint = [[MKPointAnnotation alloc] init];
annotationPoint.coordinate = locCoord;
NSString *latitude = [NSString stringWithFormat:#"%f",locCoord.latitude];
NSString *longitude = [NSString stringWithFormat:#"%f", locCoord.longitude];
annotationPoint.title = #"Event";
annotationPoint.subtitle = [NSString stringWithFormat:#"%# & %#", latitude, longitude];
[mapView addAnnotation:annotationPoint];
[[NSUserDefaults standardUserDefaults] setObject:latitude forKey:#"FolderLatitude"];
[[NSUserDefaults standardUserDefaults] setObject:longitude forKey:#"FolderLongitude"];
[annotationPoint release]; // Remove this if you're using ARC.
} while (existingpoints == 0);
}
}
Note that I've also changed the code for creating latitude and longitude for not to create any memory leaks when using ARC.
EDIT:
Further analyzing your code, I don't see why this method would be dropping two pins at once. Maybe you could check if your method is not being called twice?
More: Why do you have a do/while loop if you just want it to run once? (but maybe you're just paving your ground to further ahead)
I'm very new to programming, and I jumped right into a project (I know thats not the smartest thing to do, but I'm learning as I go). The app that I'm writing has 10 UIImageViews that display a picture from the users camera roll. The code I'm using needs each of the UIImageViews to have tags. I'm currently using NSData to save the array images, and it works great, but I can't use this method anymore because NSData doesn't support the use of tags. I also can't use NSUserDefaults, because I can't save images to a plist. Here is how I'm attempting to do this (using the NSData method, which works but I have to edit this so that my tags work.)
This is my current code:
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)img editingInfo:(NSDictionary *)editInfo {
if (imageView.image == nil) {
imageView.image = img;
[self.array addObject:imageView.image];
[picker dismissModalViewControllerAnimated:YES];
[self.popover dismissPopoverAnimated:YES];
return;
}
if (imageView2.image == nil) {
imageView2.image = img;
NSLog(#"The image is a %#", imageView);
[self.array addObject:imageView2.image];
[picker dismissModalViewControllerAnimated:YES];
[self.popover dismissPopoverAnimated:YES];
return;
}
...
- (void)applicationDidEnterBackground:(UIApplication*)application {
NSLog(#"Image on didenterbackground: %#", imageView);
[self.array addObject:imageView.image];
[self.array addObject:imageView2.image];
[self.user setObject:self.array forKey:#"images"];
[user synchronize];
}
- (void)viewDidLoad
{
self.user = [NSUserDefaults standardUserDefaults];
NSLog(#"It is %#", self.user);
self.array = [[self.user objectForKey:#"images"]mutableCopy];
imageView.image = [[self.array objectAtIndex:0] copy];
imageView2.image = [[self.array objectAtIndex:1] copy];
UIApplication *app = [UIApplication sharedApplication];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(applicationDidEnterBackground:)
name:UIApplicationDidEnterBackgroundNotification
object:app];
[super viewDidLoad];
}
Any help or suggestions on how to edit this code so that I can save the images, while using tags is much appreciated, thanks!
EDIT: Here is my updated code:
-(IBAction)saveButtonPressed:(id)sender {
NSString *docsDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES) objectAtIndex:0];
for (UIImageView *imageView in self.array) {
NSInteger tag = self.imageView.tag;
UIImage *image = self.imageView.image;
NSString *imageName = [NSString stringWithFormat:#"Image%i.png",tag];
NSString *imagePath = [docsDir stringByAppendingPathComponent:imageName];
[UIImagePNGRepresentation(image) writeToFile:imagePath atomically:YES];
}
NSLog(#"Saved Button Pressed");
}
- (void)applicationDidEnterBackground:(UIApplication*)application {
}
-(void)viewDidLoad {
NSString *docsDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES) objectAtIndex:0];
NSArray *docFiles = [[NSFileManager defaultManager]contentsOfDirectoryAtPath:docsDir error:NULL];
for (NSString *fileName in docFiles) {
if ([fileName hasSuffix:#".png"]) {
NSString *fullPath = [docsDir stringByAppendingPathComponent:fileName];
UIImage *loadedImage = [UIImage imageWithContentsOfFile:fullPath];
if (!imageView.image) {
imageView.image = loadedImage;
} else {
imageView2.image = loadedImage;
}
}
}
}
You need to use "Fast Enumeration" to parse the array's objects, and write each object to disk sequentially. First, you're going to need to add the UIImageView objects to the array instead of the UIImage property of the UIImageView, so you can recover the tag. So instead of writing
[self.array addObject:imageView.image];
It will be
[self.array addObject:imageView];
Try to follow along with my code. I inserted comments on each line to help.
-(void)applicationDidEnterBackground:(UIApplication *)application {
//Obtain the documents directory
NSString *docsDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainmask,YES) objectAtIndex:0];
//begin fast enumeration
//this is special to ObjC: it will iterate over any array one object at a time
//it's easier than using for (i=0;i<array.count;i++)
for (UIImageView *imageView in self.array) {
//get the imageView's tag to append to the filename
NSInteger tag = imageView.tag;
//get the image from the imageView;
UIImage *image = imageView.image;
//create a filename, in this case "ImageTAGNUM.png"
NSString *imageName = [NSString stringWithFormat:#"Image%i.png",tag];
//concatenate the docsDirectory and the filename
NSString *imagePath = [docsDir stringByAppendingPathComponent:imageName];
[UIImagePNGRepresentation(image) writeToFile:imagePath atomically:YES];
}
}
To load the images from disk, you'll have to look at your viewDidLoad method
-(void)viewDidLoad {
//get the contents of the docs directory
NSString *docsDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainmask,YES) objectAtIndex:0];
//Get the list of files from the file manager
NSArray *docFiles = [[NSFileManager defaultManager]contentsOfDirectoryAtPath:docsDir error:NULL]);
//use fast enumeration to iterate the list of files searching for .png extensions and load those
for (NSString *fileName in docFiles) {
//check to see if the file is a .png file
if ([fileName hasSuffix:#".png"]) {
NSString *fullPath = [docsDir stringByAppendingPathComponent:fileName];
UIImage *loadedImage = [UIImage imageWithContentsOfFile:fullPath];
//you'll have to sort out how to put these images in their proper place
if (!imageView1.image) {
imageView1.image = loadedImage;
} else {
imageView2.image = loadedImage;
}
}
}
}
Hope this helps
One thing you need to be aware of is that when an app enters the background it has about 5 seconds to clean up its act before it's suspended. The UIPNGRepresentation() function takes a significant amount of time and is not instantaneous. You should be aware of this. It would probably be better to write some of this code in other places and do it earlier than at app backgrounding. FWIW
You can use the [NSbundle Mainbundel] to store that images.
To get path
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
First, there's still a problem in your for loop.
for (UIImageView *imageView in self.array) {
NSInteger tag = self.imageView.tag;
UIImage *image = self.imageView.image;
// ...
}
Before you make any other changes, you must understand why. imageView is your for loop control variable, which changes on each iteration through the loop. self.imageView is a different thing. It is the first of the 10 imageViews attached to your viewController. Every time this loop cycles, it looks at the first imageView, and only the first.
As for why saving doesn't work, it's probably because the arrays elsewhere aren't working. Add some logging to make sure there's something in the array, and that it has as many elements as you expect.
-(IBAction)saveButtonPressed:(id)sender {
NSString *docsDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES) objectAtIndex:0];
// Log to make sure the views expected have previously been stored.
// If the array is empty, or shorter than expected, the problem is elsewhere.
NSLog(#"Image view array before saving = %#", self.array);
for (UIImageView *imageViewToSave in self.array) {
NSInteger tag = imageViewToSave.tag;
UIImage *image = imageViewToSave.image;
NSString *imageName = [NSString stringWithFormat:#"Image%i.png",tag];
NSString *imagePath = [docsDir stringByAppendingPathComponent:imageName];
// Log the image and path being saved. If either of these are nil, nothing will be written.
NSLog(#"Saving %# to %#", image, imagePath);
[UIImagePNGRepresentation(image) writeToFile:imagePath atomically:NO];
}
NSLog(#"Save Button Pressed");
}