Is there any way to get the name of the image which is present on the image view which is there on my screen. Please tell me ways to do this. I already searched it a lot but still have not found anything useful. Please help.
You can subclass UIImageView and add a property name or identifier.
#interface MyImageView : UIImageView{
NSString *name;
}
#property (retain) NSString *name;
-(id)initWithImage:(UIImage *)image andName:(NSString *)name;
#end;
#implementation MyImageView
#synthesize name;
-(id)initWithImage:(UIImage *)image andName:(NSString *)name
{
if(self = [super initWithImage:image]){
self.name = name;
}
return self;
}
-(void)dealloc
{
self.name = nil;
[super dealloc;]
}
You should use the tag property of the view to distinguish between different imageViews.
Related
I have looked all over the place for anyone who has experienced this issue but have yet to find anything relevant, so I thought I'd ask it myself...
I have a custom object (HitterData) which I will use to populate cells in a UITableView, then two ViewControllers (one is hitterTableViewController, the other is a "detail" view controller labeled "AddPlayerViewController").
The problem is that I can add HitterData objects to the NSMutableArray in my Table VC, but only one, and then when I add another one using the detail view controller, the Mutable array is "reinitialized" and I can again only have one object at a time.
HitterObject:
#implementation HitterData.m
#synthesize hitterName = _hitterName;
#synthesize position = _position;
-(id)initWIthNameAndPosition:(NSString *)hitterName position:(NSString *)position {
if ((self = [super init])) {
self.hitterName = _hitterName;
self.position = _position;
}
return self;
}
HitterTableViewController.h
#import "HitterData.h"
#import "HitterDoc.h"
#import "AddPlayerViewController.h"
#interface HitterTableViewController : UITableViewController
#property (nonatomic, strong) NSMutableArray *hitters;
- (IBAction)backButton:(id)sender;
- (IBAction)addPlayerView:(id)sender;
-(void)addHitterObject:(HitterData *)hitter;
HitterTableViewController.m (only relevant to make this more readable)
#implementation HitterTableViewController
#synthesize hitters = _hitters;
- (void)viewDidLoad {
[super viewDidLoad];
self.hitters = [NSMutableArray array];
}
-(void)addHitterObject:(HitterData *)hitter {
if(_hitters != nil) {
[_hitters addObject:hitter];
} else {
_hitters = [NSMutableArray array];
[_hitters addObject:hitter];
NSLog(#"MutableArray is not valid");
}
}
AddPlayerViewController.h
#interface AddPlayerViewController : UIViewController <UITextFieldDelegate, UINavigationControllerDelegate>
#property (weak, nonatomic) IBOutlet UITextField *nameTextField;
#property (weak, nonatomic) IBOutlet UITextField *positionTextField;
#property (nonatomic) HitterTableViewController *hitterTable;
#property (nonatomic) NSString *hitterName;
#property (nonatomic) NSString *position;
//-(void)addNewHitterToHittersArray:(HitterData *)hitter;
- (IBAction)addPlayerToRoster:(id)sender;
AddPlayerViewController.m
#implementation AddPlayerViewController
#synthesize hitterTable;
- (void)viewDidLoad {
[super viewDidLoad];
hitterTable = [[HitterTableViewController alloc] init];
}
- (IBAction)addPlayerToRoster:(id)sender {
self.hitterName = [self.nameTextField text];
self.position = [self.positionTextField text];
HitterData *hitter = [[HitterData alloc] init];
hitter.hitterName = self.hitterName;
hitter.position = self.position;
[hitterTable addHitterObject:hitter];
ArraySingleton *arrayS = [[ArraySingleton alloc] init];
[arrayS initializeArray];
[arrayS addToHittersArray:hitter];
if (arrayS) {
NSLog(#"arrayS exists in AddPlayerVC");
} else {
NSLog(#"arrayS does not exist");
}
[self performSegueWithIdentifier:#"backToTeamTableViewController" sender:self];
}
Am I missing something here?
Guess based just on the code shown:
Every time you wish to add a player it looks like you create a new AddPlayerView/AddPlayerViewController. In turn that controller creates, in its viewDidLoad, a new HitterTableViewController - which of course has its own empty array. The code should instead be referencing the existing HitterTableViewController.
BTW: The common design pattern is MVC - model, view, controller - consider whether you are in your current situation because you've stored part of your model, the array, in your controller, and maybe both controllers should be referencing a common shared model object containing that array.
BTW: All those #synthesise statements are unneeded. In modern Obj-C synthesis is automatic and you rarely need these statements. Also it is generally recommended to not use the property backing variable directly, and certainly not when storing into the property as this breaks KVO. (There also appears to be a related typo in HitterData.m but as you don't report that as not working it is probably just a typo in your question and not code.)
HTH
AddPlayerViewController should know nothing about HitterTableViewController, return the new HitterData object with a delegate method.
- (IBAction)addPlayerToRoster:(id)sender
{
Hitter *hitter = [[Hitter alloc] init];
hitter.name = [self.nameTextField text];
hitter.position = [self.positionTextField text];
[self.delegate didAddHitter:hitter];
}
Then back in HitterTableViewController
- (void)didAddHitter:(Hitter *)hitter
{
[self.hitters addHitter:hitter];
[self dismissViewControllerAnimated:YES completion:nil];
}
i need to build an application that define an array that should be made of image items.
every image iten has an image, a name and a photographer name.
i build my image item class and i want you to check if my define is correct and good(i just start to learn objective c).
i want you to emphasize on the set's methods.
here is the photoitem.h:
#import <Foundation/Foundation.h>
#interface photoItem : NSObject
{
UIImage *imageView;
NSString *photoNameLabel;
NSString *photographerNameLabel;
UIButton *viewPhoto;
}
#property(readonly) NSString *name;
#property(readonly) NSString *nameOfPhotographer;
#property(readonly) UIImage *imageItem;
-(id)makePhotoItemWIthPhoto:(UIImage*)image name:(NSString*)photoName photographer: (NSString*)photographerName;
#end
here is my photoitem.m:
#import "photoItem.h"
#implementation photoItem
#synthesize name;
#synthesize nameOfPhotographer;
#synthesize imageItem;
-(id)makePhotoItemWIthPhoto:(UIImage*)image name:(NSString*)photoName photographer:(NSString*)photographerName
{
[self setName:photoName];
[self setNameOfPhotographer:photographerName];
[self setImageItem:image];
return self;
}
-(void) setName:(NSString *)name
{
photoNameLabel = name;
}
-(void) setNameOfPhotographer:(NSString *)nameOfPhotographer
{
photographerNameLabel = nameOfPhotographer;
}
-(void)setImageItem:(UIImage *)imageItem
{
imageView = imageItem;
}
#end
i hope you could fix my errors(if there are some).
thanks.
Two problems come to mind:
1) -(id)makePhotoItemWIthPhoto:name:photographer: might be better as -(id)initWithPhoto:name:photographer:. Otherwise the caller needs to alloc and init an object first so that self is valid, then call your method. At that point, the return of self doesn't make sense.
Example:
-(idinitWithPhoto:(UIImage*)image name:(NSString*)photoName photographer:(NSString*)photographerName {
self = [super init];
if (self) {
[self setName:photoName];
[self setNameOfPhotographer:photographerName];
[self setImageItem:image];
}
return self;
}
2) The three readonly properties don't seem to have any purpose since they have no connection to the variables that you initialize in the makePhotoItemWIthPhoto: method.
I am trying to make a practice application that takes two entered words (word1, word2) and puts them together to make a compound word. I am very new to this and would like to know the correct way to display these two variables under the action "buttonPressed."
Here's the header file...
#import <UIKit/UIKit.h>
#interface Word_CombinerViewController : UIViewController {
UITextField *word1;
UITextField *word2;
UITextField *display;
UIButton *mashButton;
}
#property (nonatomic, retain) IBOutlet UITextField *word1;
#property (nonatomic, retain) IBOutlet UITextField *word2;
#property (nonatomic, retain) IBOutlet UITextField *display;
#property (nonatomic, retain) IBOutlet UIButton *mashButton;
-(IBAction)textFieldDoneEditing:(id)sender;
-(IBAction)backgroundTap:(id)sender;
-(IBAction)buttonPressed:(id)sender;
#end
And here's the implementation file (.m)...
#import "Word_CombinerViewController.h"
#implementation Word_CombinerViewController
#synthesize word1;
#synthesize word2;
#synthesize display;
#synthesize mashButton;
-(IBAction)textFieldDoneEditing:(id)sender {
[sender resignFirstResponder];
}
-(IBAction)backgroundTap:(id)sender {
[word1 resignFirstResponder];
[word2 resignFirstResponder];
}
-(IBAction)buttonPressed:(id)sender {
NSString *newText = [NSString: #word1, #word2]
display.text = newText;
[newText release]
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)dealloc {
[word1 release];
[word2 release];
[display release];
[mashButton release];
[super dealloc];
}
#end
I know this code is probably full of errors, but everyone has gotta start somewhere, right?
Any feedback would be greatly appreciated, thank you!
NSString *newText = [NSString: #word1, #word2]
This code doesn't make any sense. The first part of a message is the receiver, and it won't have any colons in it. The second part is the message itself, i.e. the method name along with any necessary parameters. What you're looking for is:
NSString *newText = [NSString stringWithFormat:#"%#%#", word1, word2];
The -stringWithFormat: method uses a format string (very much like printf()) and a variable number of parameters to fill in the placeholders in the format string.
Also, when you create a string (or any object) using a "convenience method" like this, you shouldn't release it. You didn't retain or alloc or copy it, so it's not your responsibility to release it. You'll want to remove that line from your -buttonPressed method.
Try this:
-(IBAction)buttonPressed:(id)sender {
NSString *newText = [word1.text stringByAppendingString:word2.text]
display.text = newText;
}
I'm new to objective-c and I'm finding that I don't know how to correctly assert that a text property on some given label is equal to a raw string value. I'm not sure if I just need to cast the label as NSString or if I need to modify my assert statement directly.
#interface MoreTest : SenTestCase {
MagiczzTestingViewController* controller;
}
- (void) testObj;
#end
#implementation MoreTest
- (void) setUp
{
controller = [[MagiczzTestingViewController alloc] init];
}
- (void) tearDown
{
[controller release];
}
- (void) testObj
{
controller.doMagic;
STAssertEquals(#"hehe", controller.label.text, #"should be hehe, was %d instead", valtxt);
}
#end
The implementation of my doMagic method is below
#interface MagiczzTestingViewController : UIViewController {
IBOutlet UILabel *label;
}
#property (nonatomic, retain) UILabel *label;
- (void) doMagic;
#end
#implementation MagiczzTestingViewController
#synthesize label;
- (void) doMagic
{
label.text = #"hehe";
}
- (void)dealloc {
[label release];
[super dealloc];
}
#end
The build is fine when I modify the assert to compare a raw NSString to another but when I try to capture the text value (assuming it's of type NSString) it fails. Any help would be much appreciated!
STAssertEquals() checks for identity of the two values provided, so it's equivalent to doing this:
STAssertTrue(#"hehe" == controller.label.text, ...);
Instead, you want STAssertEqualObjects(), which will actually run an isEqual: check like the following:
STAssertTrue([#"hehe" isEqual:controller.label.text], ...);
You need to load the nib of the view controller. Otherwise there won't be any objects for the label outlet to be hooked up to.
One way to do this is to add an ivar for the view controller's view to your test case:
#interface MoreTest : SenTestCase {
MagiczzTestingViewController *controller;
UIView *view;
}
#end
#implementation MoreTest
- (void)setUp
{
[super setUp];
controller = [[MagiczzTestingViewController alloc] init];
view = controller.view; // owned by controller
}
- (void)tearDown
{
view = nil; // owned by controller
[controller release];
[super tearDown];
}
- (void)testViewExists
{
STAssertNotNil(view,
#"The view controller should have an associated view.");
}
- (void)testObj
{
[controller doMagic];
STAssertEqualObjects(#"hehe", controller.label.text,
#"The label should contain the appropriate text after magic.");
}
#end
Note that you also need to invoke super's -setUp and -tearDown methods appropriately from within yours.
Finally, do not use dot syntax for method invocation, it is not a generic replacement for bracket syntax in message expressions. Use dot syntax only for getting and setting object state.
Ok, so I have this, but it wont work:
#interface UILabel (touches)
#property (nonatomic) BOOL isMethodStep;
#end
#implementation UILabel (touches)
-(BOOL)isMethodStep {
return self.isMethodStep;
}
-(void)setIsMethodStep:(BOOL)boolean {
self.isMethodStep = boolean;
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
if(self.isMethodStep){
// set all labels to normal font:
UIFont *toSet = (self.font == [UIFont fontWithName:#"Helvetica" size:16]) ? [UIFont fontWithName:#"Helvetica-Bold" size:16] : [UIFont fontWithName:#"Helvetica" size:16];
id superView = self.superview;
for(id theView in [(UIView *)superView subviews])
if([theView isKindOfClass:[UILabel class]])
[(UILabel *)theView setFont:[UIFont fontWithName:#"Helvetica" size:16]];
self.font = toSet;
}
}
#end
If I take out the getter and setter methods then it doesn't work it tells me I need to create some getter and setter methods (or use #synthesize - but putting #synthesize in the #implementation throws an error too). But with the getter and setter methods I get an EXC_BAD_ACCESS and a crash. Any ideas? Thanks
Tom
It is not possible to add members and properties to an existing class via a category — only methods.
https://developer.apple.com/library/content/documentation/General/Conceptual/DevPedia-CocoaCore/Category.html
One possible workaround is to write "setter/getter-like" methods, that uses a singleton to save the variables, that would had been the member.
-(void)setMember:(MyObject *)someObject
{
NSMutableDictionary *dict = [MySingleton sharedRegistry];
[dict setObject:someObject forKey:self];
}
-(MyObject *)member
{
NSMutableDictionary *dict = [MySingleton sharedRegistry];
return [dict objectforKey:self];
}
or — of course — write a custom class, that inherits from UILabel
Note that nowadays an associated object can be injected during runtime. The Objective C Programming Language: Associative References
Checked all answers and did not find the most common solution:
#import <objc/runtime.h>
static void const *key;
#interface ClassName (CategoryName)
#property (nonatomic) BOOL myProperty;
#end
#implementation ClassName (CategoryName)
- (BOOL)myProperty {
return [objc_getAssociatedObject(self, key) boolValue];
}
- (void)setMyProperty:(BOOL)value {
objc_setAssociatedObject(self, key, #(value), OBJC_ASSOCIATION_RETAIN);
}
#end
swift:
private struct AssociatedKeys {
static var keyName = "keyName"
}
extension Foo {
var bar: Any! {
get {
return objc_getAssociatedObject(self, &AssociatedKeys.keyName)
}
set {
objc_setAssociatedObject(self, &AssociatedKeys.keyName , newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
}
}
}
There is actually a way, which may not be ideal, but does work.
For it to work, you will need to create a category for a class X and can only be used on subclasses of the same X (e.g. category UIView (Background) can be used with class MyView : UIView, but not directly with UIView)
// UIView+Background.h
#interface UIView (Background)
#property (strong, nonatomic) NSString *hexColor;
- (void)someMethodThatUsesHexColor;
#end
// UIView+Background.h
#implementation UIView (Background)
#dynamic hexColor; // Must be declared as dynamic
- (void)someMethodThatUsesHexColor {
NSLog(#"Color %#", self.hexColor);
}
#end
Then
// MyView.m
#import "UIView+Background.h"
#interface MyView : UIView
#property (strong, nonatomic) NSString *hexColor;
#end
#implementation MyView ()
- (void)viewDidLoad {
[super viewDidLoad];
[self setHexColor:#"#BABACA"];
[self someMethodThatUsesHexColor];
}
#end
Using this method, you will need to "redeclare" your properties, but after that, you can do all of its manipulation inside your category.
You could inject an associated object during runtime.
#import <objc/runtime.h>
#interface UIView (Private)
#property (nonatomic, assign) CGPoint initialTouchPoint;
#property (nonatomic, strong) UIWindow *alertWindow;
#end
#implementation UIView (Private)
#dynamic initialTouchPoint, alertWindow;
- (CGPoint)initialTouchPoint {
return CGPointFromString(objc_getAssociatedObject(self, #selector(initialTouchPoint)));
}
- (void)setInitialTouchPoint:(CGPoint)initialTouchPoint {
objc_setAssociatedObject(self, #selector(initialTouchPoint), NSStringFromCGPoint(initialTouchPoint), OBJC_ASSOCIATION_RETAIN);
}
- (void)setAlertWindow:(UIWindow *)alertWindow {
objc_setAssociatedObject(self, #selector(alertWindow), alertWindow, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
- (UIWindow *)alertWindow {
return objc_getAssociatedObject(self, #selector(alertWindow));
}
#end
EDIT: Warning: This property would have a unique value for all the instances of the class.
This worked for me, but only because I had only one instance of this class in my app.
#import <AVFoundation/AVFoundation.h>
#interface AVAudioPlayer (AstroAVAudioPlayer)
#property (nonatomic) BOOL redPilot;
#end
#import "AVAudioPlayer+AstroAVAudioPlayer.h"
#implementation AVAudioPlayer (AstroAVAudioPlayer)
BOOL _redPilot;
-(void) setRedPilot:(BOOL)redPilot
{
_redPilot = redPilot;
}
-(BOOL) redPilot
{
return _redPilot;
}
#end
A solution that I found to this was to just give each object that you want flagged a unique tag.
I made a UILabel category to add custom fonts to all my labels but on some i wanted them to be bold so i did this ->
- (void) layoutSubviews {
[super layoutSubviews];
[self addCustomFont];
}
- (void) addCustomFont {
if (self.tag == 22) {
[self setFont:[UIFont fontWithName:SEGOE_BOLD size:self.font.pointSize]];
}else{
[self setFont:[UIFont fontWithName:SEGOE_LIGHT size:self.font.pointSize]];
}
}
It seems as if since Xcode 7 (7.0.1, 7A1001), properties are supported in categories. I noticed that Xcode generates categories now for Core Data subclasses.
For example, I got the files:
Location+CoreDataProperties.h
#import "Location.h"
NS_ASSUME_NONNULL_BEGIN
#interface Location (CoreDataProperties)
#property (nullable, nonatomic, retain) NSNumber *altitude;
#property (nullable, nonatomic, retain) NSNumber *latitude;
#property (nullable, nonatomic, retain) NSNumber *longitude;
#end
NS_ASSUME_NONNULL_END
Location+CoreDataProperties.m
#import "Location+CoreDataProperties.h"
#implementation Location (CoreDataProperties)
#dynamic altitude;
#dynamic latitude;
#dynamic longitude;
#end
So looks like properties in categories might work now. I haven't tested on non-Core Data classes.
What I've noticed is that they do include the category file back into the original class:
Location.h
#interface Location : NSManagedObject
#end
#import "Location+CoreDataProperties.h"
This allows the original class to edit the properties specified by the category.