iOS - Storing groups of UILabels into a NSMutableArray

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 th开发者_如何学Cought 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];