I am setting the array for a series of views with the following code. bunnyView1 through bunnyView7 are instances of UIImageView created in the storyboard but I want to automate the process so I can generate the connections with code. How would I set the values inside a loop?
- (void)viewDidLoad
{
NSMutableArray *hopAnimation = [[NSMutableArray alloc] initWithCapacity:20];
for (int i = 1; i <= 20; i++) {
[hopAnimation addObject:[UIImage imageNamed:[NSString stringWithFormat:#"frame-%i.png", i]]];
}
self.bunnyView1.animationImages=hopAnimation;
self.bunnyView2.animationImages=hopAnimation;
self.bunnyView3.animationImages=hopAnimation;
self.bunnyView4.animationImages=hopAnimation;
self.bunnyView5.animationImages=hopAnimation;
self.bunnyView6.animationImages=hopAnimation;
self.bunnyView7.animationImages=hopAnimation;
self.bunnyView1.animationDuration=1;
self.bunnyView2.animationDuration=1;
self.bunnyView3.animationDuration=1;
self.bunnyView4.animationDuration=1;
self.bunnyView5.animationDuration=1;
self.bunnyView6.animationDuration=1;
self.bunnyView7.animationDuration=1;
[super viewDidLoad];
}
Add your variables in an Array. And iterate the array and set values . For ex,
NSArray *collection = [[NSArray alloc]initWithObjects:#"object1",#"object2",#"object3",#"object4",nil];
You should use an IBOutletCollection of UIImageView which every bunnyView should be linked to. Declaration goes like this:
#property (nonatomic,retain) IBOutletCollection(UIImageView) NSArray * bunnyViews;
Related
I am new to Objective-C and learning by trial and error! Please forgive me if this question is somewhat naïve.
I've created an array of images and need to shuffle them. I've used the advice given here:
What's the Best Way to Shuffle an NSMutableArray?
And now I need to implement the method 'shuffle'. I have separate category for my array and its implementation:
#interface theKid : NSObject {
NSMutableArray* _cards;
}
#property(strong, nonatomic, readonly) NSMutableArray *cards;
- (UIImage*) shuffledCard;
#end
But now I can't figure out how to implement 'shuffle':
#implementation theKid
- (NSMutableArray *) cards {
_cards = [[NSMutableArray alloc] initWithObjects:
[UIImage imageNamed:#"One"],
[UIImage imageNamed:#"Two"],
[UIImage imageNamed:#"Three"],
[UIImage imageNamed:#"Four"], nil];
return _cards;
}
- (UIImage*) shuffledCard {
shuffle *cards;
return [cards objectAtIndex:0];
}
#end
This just effects a blank screen when I try to call 'shuffledCard'. Any advice much appreciated.
Hi i have pasted few lines of code below which will Shuffle an NSMutable Array exactly like what you want.
NSMutableArray * _cards = [[NSMutableArray alloc] init];
[_cards addObject:[UIImage imageNamed:#"One.png"]];
[_cards addObject:[UIImage imageNamed:#"Two.png"]];
[_cards addObject:[UIImage imageNamed:#"Three.png"]];
[_cards addObject:[UIImage imageNamed:#"Four.png"]];
[_cards addObject:[UIImage imageNamed:#"Five.png"]];
// Add the below code in the Shuffle Method
NSUInteger count = [_cards count];
for (NSUInteger i = 0; i < count; ++i)
{
NSInteger remainingCount = count - i;
int exchangeIndex = i + arc4random_uniform(remainingCount);
[_cards exchangeObjectAtIndex:i withObjectAtIndex:exchangeIndex];
UIImage * image = [_cards objectAtIndex:i];
}
Just use this api for shuffling of object exchangeObjectAtIndex:withObjectAtIndex: Refer this how to shuffle object in NSMutableArray?
I am new to Objective C coming from C# .NET, I have this scenario :
Assume I have 5 NSArrays corresponding to 5 UIButtons. the UIButtons have the exact same name
as the NSArray, so for example one UIButton is called mainScreen, and there is an NSArray called mainScreen.
Those Five buttons are linked to one IBAction where I do the following :
- (IBAction)btnClick:(id)sender {
NSString *category = [(UIButton *)sender currentTitle];
NSLog(category);
//Here I need to call the NSArray which has the same name as category
}
Now I can get the actual name of the UIButton, but how can I get the NSArray same as that title? without getting into a lot of if else or switch statements?
What I would do is store the arrays inside an NSDictionary. You can then set the 'key' as the name of your array and then the value would be the array itself.
That way you could say:
- (IBAction)btnClick:(id)sender {
NSString *category = [(UIButton *)sender currentTitle];
NSLog(category);
//Here I need to call the NSArray which has the same name as category
NSArray *theArray = (NSArray*)[self.myDictionary valueForKey:category];
}
Hope this helps!
The easiest way to associate names with objects is using an NSDictionary (or it's mutable subclass NSMutableDictionary). Dictionaries map a unique key to an object. Keys can be any object (that implements the NSCopying protocol), but are very often NSStrings
Have a look at the NSDictionary Reference and the Programming with Objective-C guide.
Note that if you use the button title this might break if you localise your app.
What you do is not the best way. You should provide tag for each button, say from 1 to 5. Also you should put your five arrays into one array. Now all you need is:
- (IBAction)btnClick:(id)sender
{
NSInteger index = [sender tag] - 1;
NSArray *array = [bigArray objectAtIndex:index];
}
That's it.
Assign different tags to all UIButtons and then access them explicitly using their tags.
- (IBAction)btnClick:(id)sender {
int tagIs = [(UIButton *)sender tag];
switch (tagIs) {
case 1:
// Access first button array
break;
case 2:
// Access second button array
break;
default:
break;
}
}
Or you can use AssociationObjects method for associating data with objects as following:
Firstly import :
#import <objc/runtime.h>
then create keys as :
static char * firstBtnKey = "firstBtnKey";
static char * secondBtnKey = "secondBtnKey";
-- - other keys same way ---
then use :
// Do any additional setup after loading the view, typically from a nib.
NSMutableArray *firstArray = [[NSMutableArray alloc] initWithObjects:#"object1",#"object 2", nil];
objc_setAssociatedObject((UIButton *)[self.view viewWithTag:1],
firstBtnKey,
firstArray,
OBJC_ASSOCIATION_RETAIN);
NSMutableArray *secondArray = [[NSMutableArray alloc] initWithObjects:#"object1",#"object 2", nil];
objc_setAssociatedObject((UIButton *)[self.view viewWithTag:2],
secondBtnKey,
secondArray,
OBJC_ASSOCIATION_RETAIN);
`
and then access these arrays as :
- (IBAction)btnClick:(id)sender {
int tagIs = [(UIButton *)sender tag];
switch (tagIs) {
case 1:
// Access first button array
NSMutableArray *tempArr = (NSMutableArray *)objc_getAssociatedObject((UIButton *)sender, firstBtnKey);
break;
case 2:
// Access second button array
NSMutableArray *tempArr = (NSMutableArray *)objc_getAssociatedObject((UIButton *)sender, secondBtnKey);
break;
default:
break;
}
}
Hope it helps.
In most programming languages objects don't have names.[1] Just because UIButtons have the exact same name as the NSArray(mainScreen), doesn't mean that your object is "called" mainScreen.
Use NSDictionary , array as object and button title as key.
or use button tag
title1= [[NSArray alloc] initWithObjects:#"1",nil];
title2= [[NSArray alloc] initWithObjects:#"2",nil];
title3= [[NSArray alloc] initWithObjects:#"3",nil];
title4= [[NSArray alloc] initWithObjects:#"4",nil];
title5= [[NSArray alloc] initWithObjects:#"5",nil];
dict = [[NSDictionary alloc] initWithObjectsAndKeys:title1,#"title1",title2,#"title2",title3,#"title3",title4,#"title4",title5,#"title5",nil];
- (IBAction)btnClick:(id)sender {
NSString *category = [(UIButton *)sender currentTitle];
NSArray *arr = [dict objectForKey:category];
}
I want to use the variable of a for loop in a property name, example:
#interface
{
Player *rival1, *rival2, *rival3;
}
int number;
for (number=1; number<=3; number++){
rival+number = [[Player alloc] init]; //The compiler accepts this.
rival+number.name = #"";
//^This line gives the error: "use of undeclared identifier 'rival'"
//For the first loop, I want it work like: rival1.name = #"";
}
This isn't a particularly clean way of approaching this, but to answer the question as you've posed it:
- (void)generateRivals
{
for (int i = 1; i < 4; i++)
{
NSString *propertySetString = [NSString stringWithFormat:#"setRival%d", i];
Rival *rival = [[Rival alloc] init];
[self performSelector:#selector(NSSelectorFromString(propertySetString)) withObject:rival];
}
}
We create a selector (I haven't tested this, but it should work in theory) that corresponds to the getter for the property instance represented by i.
Based on comments you've added, it seems like what you really want is a variable number of players (perhaps not exceeding a certain number) with the ability to reference them individually.
Architecturally, rather than create properties pointing to each respective rival, put them all in an array (and keep it as a property on your class). So you'd create them like this:
- (void)generateRivals:(NSUInteger)numberOfRivals
{
NSMutableArray *rivalsArray = [[NSMutableArray alloc] initWithCapacity:numberOfRivals];
for (int i = 0; i < numberOfRivals; i++)
{
Rival *rival = [[Rival alloc] init];
[rivalsArray insertObject:rival atIndex:i];
}
[self setRivalsArray:rivals];
}
Then, when you need to access a particular rival, call a method like this, which will return the rival at the index number you pass:
- (Rival *)rivalWithNumber:(NSUInteger)number
{
return [[self rivalsArray] objectAtIndex:number];
}
you cant create the properties variable names on the fly and use it, as the names get lost during compilation
you can put them in an array and enumerate over it
Player rival1 = [[Player alloc] init];
Player rival2 = [[Player alloc] init];
Player rival3 = [[Player alloc] init];
for (Player *p in #[rival1, rival2, rival3]) {
p.name = #"";
}
probably the best way would be to maintain the rivales in the array from the beginning
#interface …
#property(strong) NSArray *rivals;
#end
#implementation …
//in some useful method, like initializer
_rivals = [NSMutableArray array]
for (int i = 0; i < 3 ++i){
//create player and add to array
}
#end
You might want to look into Key Value Coding.
You need to create properties for your rivals
#interface …
#property(strong) Player *rival1;
#property(strong) Player *rival2;
#property(strong) Player *rival3;
#end
#implementation …
-(id)init…
{
if(self = [super init…]){
for (int i = 1; i < 4; ++i) {
Player *rival = [[Player alloc] init];
rival.name = [NSString stringWithFormat:#"rival%d", i];
[self setValue: rival forKey:[NSString stringWithFormat:#"rival%d", i]];
}
}
return self;
}
#end
Instead of running a for loop to set the names of the players to #"" just add the line
name = #"" in your init method of your Player class. It's faster and more practical than to write a for loop. You can also create a method like
-(id)initWithName:(NSString *)initName{
self = [super init];
if (self){
name = initNane;
}
return self;
}
to set the name of your player at the moment it's created. Although if you want absolutely a for loop, you can use the method posted by vikingosegundo previously.
I'm creating UILabels dynamically in a for each loop. Every loop that is run creates 1-4 UILabels.
What I want is that I put these UILabels into my NSMutableArray and being able later to easy retrieve the data.
My original thought was to put these UILabels into a NSDictionary and use [dictGroupLabels setValue:uiLabel1 forKey:#"uiLabel1"] and then [dictGroupLabels setValue:uiLabel2 forKey:#"uiLabel2"] and so on. And then put this dictionary into my NSMutableArray for each loop. Later on I could access the values like UILabel *label = [[myArray objectAtIndex:0] valueForKey:#"uiLabel1"] BUT that unfortunately doesn't work since UILabels don't conform to the NSCopying protocol.
So with this in mind how would you solve this?
this question provided more information on what you are trying to accomplish. Since you know for a fact, the possible set of labels you are trying to create in each case, I would highly recommend using mutable dictionaries instead of arrays.
To illustrate, given the following hypothetical class definition:
#interface MyClass: NSObject {
NSMutableDictionary * _labelDict;
}
#property (nonatomic, retain) NSMutableDictionary * labelDict;
- ( void )methodA;
- ( void )methodB;
- (NSMutableDictionary *) labelsForRunLoop: (NSUInteger) loopIdx;
#end
You would have the following, hypothetical, class implementation:
#implementation MyClass
#synthesize labelDict = _labelDict;
- ( id ) init {
if( ( self = [ super init ] ) ) {
[self setLabelDict: [NSMutableDictionary dictionaryWithCapacity: 8]];
}
}
- ( void ) dealloc {
[ self.labelDict release ];
[ super dealloc ];
}
- ( void ) methodA {
for(NSUInteger i = 0; i < some index; i++) {
[self.labelDict setObject: [self labelsForRunLoop: i] forKey: [NSString stringWithFormat: #"%d", i]];
}
}
- ( void ) methodB {
// Locate the label you need to work with. Example based on this crude pseudo code
NSMutableDictionary * subDict = (NSMutableDictionary *) [self.labelDict objectForKey: #"0"];
UILabel * theLabel = (UILabel * ) [subDict objectForKey: #"UILabel.Z"];
theLabel.text = #"Label 1";
}
- (NSMutableDictionary *) labelsForRunLoop: (NSUInteger) loopIdx {
NSMutableDictionary * dictionary = [NSMutableDictionary dictionaryWithCapacity: 4] ;
[dictionary setObject: create-w-label forKey: #"UILabel.W"];
[dictionary setObject: create-x-label forKey: #"UILabel.X"];
[dictionary setObject: create-y-label forKey: #"UILabel.Y"];
[dictionary setObject: create-z-label forKey: #"UILabel.Z"];
return [dictionary retain];
}
#end
This is basically pseudo code and will not successfully compile. However it will serve as a good starting point. You probably want to store each label dictionary under some key that makes sense, instead of just using the loop's index. Hope this helps.
They don’t need to adhere to NSCopying to be added to an array. It sounds like you just need to do something like this:
NSMutableArray *mainArray = [NSMutableArray array];
for(int i = 0; i < 5; i++)
{
NSMutableArray *subArray = [[NSMutableArray alloc] initWithCapacity:5];
for(int j = 0; j < 4; j++)
{
UILabel *label = [[UILabel alloc] init];
// etc.
[subArray addObject:label];
[label release];
}
[mainArray addObject:subArray];
[subArray release];
}
// then, to get one of the labels:
UILabel *someSpecificLabel = [[mainArray objectAtIndex:2] objectAtIndex:1];
How can I reload the data in the TTTableViewController? I tried to
call reloadData but it doesn't display the new data.
I have created the datasource file, which is a subclass of
TTListDataSource. Basically, the init function looks like this.
- (id) initWithObject:(NSArray *)objects {
if (self = [super init]) {
NSMutableArray *priceItems = [[[NSMutableArray alloc] init] autorelease];
for (int i = 0; i < [objects count]; i++) {
[priceItems addObject:
[PriceItem itemWithName:
[[objects objectAtIndex:i] objectAtIndex:0]
lastDone:[[objects objectAtIndex:i] objectAtIndex:1] change:[[objects objectAtIndex:i] objectAtIndex:2]]];
}
self.items = [NSArray arrayWithArray:priceItems];
}
return self; }
After the view is loaded, i start to streaming some data, thus the
objects passed to initWithObject is changed, so I call 'reload' in the
subclass of the TTTableViewController in order to update the data, but
the data is not updated. It doesn't work for refresh method too. Do I need to implement any other method in
the subclass of TTListDataSource?
Try
[self invalidateModel];
That should do the trick.
invalidateModel will rebuild the model, that's not efficient.
Try [TTTableViewController refresh], your table will be reloaded.