accessing array from another class in iPhone xcode

Question

i have getting CGPoint value in my array like this

@interface CanvasView : UIView{
 NSMutableArray *_array;
}
@property (nonatomic, retain) NSMutableArray *_array;

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    CGPoint currentPoint = [touch locationInView:self];
    [_array addObject:[NSValue valueWithCGPoint: currentPoint]];
}

i have called this array in touchesEnded its working fine i will get values of nspoint

    - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {  
        NSLog(@"roomAtX:%@ ",_array);
    PieClass *myPieClass=[[PieClass alloc]initWithFrame:CGRectMake(8, 297, 200, 300)];
    [self addSubview:myPieClass];
}

this is my console out put

"NSPoint: {595, 158}",
"NSPoint: {558, 154}",
"NSPoint: {535, 152}",
"NSPoint: {518, 152}",
"NSPoint: {500, 160}",
"NSPoint: {482, 175}",

now i want use this array to another class so that i called this for my another class like this

- (void)drawRect:(CGRect)rect
{
      CanvasView *cnava =[[CanvasView alloc]init];
        NSLog(@"nextview:%@ ",cnava._array);

}

but here i get nextview:(null) kindly guide how can access that array in other classes .

I don't understand what the question is. You init a new CanvasView and its property array is empty 'cause it is not initialized with data until touchesEnded:withEvent: has been executed. So before it's happen array is empty (null). What is the problem then? — Gabriel
– Gabriel, Commented Feb 9, 2012 at 7:35
You do not initialize the array could you tell us please where you initialize your _array(where you give the array it's values)? — Radu
– Radu, Commented Feb 9, 2012 at 7:39
@Radu i initialize array value for touch move mathod like this [_array addObject:[NSValue valueWithCGPoint: currentPoint]]; — Gurumoorthy Arumugam
– Gurumoorthy Arumugam, Commented Feb 9, 2012 at 7:50

Adil Soomro · Accepted Answer · 2012-02-09 07:51:17Z

1

Just have a property of PieClass

@interface PieClass : UIView{
    // ... other things.
}
@property (nonatomic, retain)NSMutableArray *pointsArray;

and don't forget to synthesize it. Now when you initialize PieClass pass that array to this also

PieClass *myPieClass=[[PieClass alloc]initWithFrame:CGRectMake(8, 297, 200, 300)];
myPieClass.pointsArray = _array;
[self addSubview:myPieClass];

now in your drawRect

- (void)drawRect:(CGRect)rect
{
      //CanvasView *cnava =[[CanvasView alloc]init]; you don't need to do this
      NSLog(@"nextview:%@ ",self.pointsArray);  //passed from previous class

}

answered Feb 9, 2012 at 7:51

Adil Soomro

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Comments

Alex Terente · Accepted Answer · 2012-02-09 07:34:38Z

0

You have to use the old object CanvasView. So if you alloc and init a new object CanvasView the _array will be null. You have to alloc the memory for the _array and initialize it or you have to set it first as a property.

So, to the current object where you want to draw you need to pass reference of the CanvasView object in witch you detect the touches and you save the points.

I hope I was clear enough.

answered Feb 9, 2012 at 7:34

Alex Terente

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Comments

ilhan çetin · Accepted Answer · 2012-02-09 07:52:36Z

0

Save the objects(in this point, the array) to NSUserDefaults in the first class

  - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
        CGPoint currentPoint = [touch locationInView:self];
        [_array addObject:[NSValue valueWithCGPoint: currentPoint]];

        NSUserDefaults *myArray=[NSUserDefaults standartuserdefaults];
        [myArray setObject:_array forKey:@"keyToArray"];

    }



    - (void)drawRect:(CGRect)rect
    {  
           NSArray *yourArray=[[NSUserDefaults standartuserdefaults] objectForKey:@"keyToArray"];
          //CanvasView *cnava =[[CanvasView alloc]init];
            NSLog(@"nextview:%@ ",yourArray);

    }

Try this

answered Feb 9, 2012 at 7:52

ilhan çetin

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Comments

Justin · Accepted Answer · 2012-02-09 07:55:19Z

0

If I understand it right you need the class to be an Singleton

You first create a class method in the .h file:

@interface CanvasView : UIView{
 NSMutableArray *_array;
}
...
+ (CanvasView *)sharedInstance;
...

Then in the .m file:

@implementation CanvasView
...
static CanvasView *sharedHelper = nil;
...
+ (CanvasView *)sharedInstance
{
    @synchronized(self) 
    {
        if (!sharedHelper) 
        {
            sharedHelper = [CanvasView new;
        }
    }
    return sharedHelper;
}

And call it like:

CanvasView *view = [CanvasView sharedInstance];

answered Feb 9, 2012 at 7:55

Justin

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