声明/初始化CGPoints数组时遇到问题

Question

Like most of my problems recently, i think it's a syntax problem. I know what i want to do but i don't know how to write it. I am trying to create a Jigsaw-type application. The CGPoints represent the center point of where each image should be.

1. I have created 40 images and put them into an array.
2. I want to create 40 CGPoints and put all these points in an array.
3. The image at images[0] has a corresponding center at cgpoints[0] - or rather this is where the image should be placed in the jigsaw.

I'm having trouble declaring/initializing the array of CGPoints though. Below is the code:

.h file

#import <UIKit/UIKit.h>

@interface DSAAssignmentViewController2 : UIViewController

@property (weak, nonatomic) NSString *passedData;
@property (weak, nonatomic) IBOutlet UILabel *lblDisplayPreviousInput;
@property (weak, nonatomic) IBOutlet UIImageView *imgOriginal;
@property (weak, nonatomic) IBOutlet UIImageView *img1;
@property (weak, nonatomic) IBOutlet UIImageView *img2;
@property (weak, nonatomic) IBOutlet UIImageView *img3;
@property (weak, nonatomic) IBOutlet UIImageView *img4;
@property (weak, nonatomic) IBOutlet UIImageView *img5;
@property (weak, nonatomic) IBOutlet UIImageView *img6;
@property (weak, nonatomic) IBOutlet UIImageView *img7;
@property (weak, nonatomic) IBOutlet UIImageView *img8;
@property (weak, nonatomic) IBOutlet UIImageView *img9;
@property (weak, nonatomic) IBOutlet UIImageView *img10;
@property (weak, nonatomic) IBOutlet UIImageView *img11;
@property (weak, nonatomic) IBOutlet UIImageView *img12;
@property (weak, nonatomic) IBOutlet UIImageView *img13;
@property (weak, nonatomic) IBOutlet UIImageView *img14;
@property (weak, nonatomic) IBOutlet UIImageView *img15;
@property (weak, nonatomic) IBOutlet UIImageView *img16;
@property (weak, nonatomic) IBOutlet UIImageView *img17;
@property (weak, nonatomic) IBOutlet UIImageView *img18;
@property (weak, nonatomic) IBOutlet UIImageView *img19;
@property (weak, nonatomic) IBOutlet UIImageView *img20;
@property (weak, nonatomic) IBOutlet UIImageView *img21;
@property (weak, nonatomic) IBOutlet UIImageView *img22;
@property (weak, nonatomic) IBOutlet UIImageView *img23;
@property (weak, nonatomic) IBOutlet UIImageView *img24;
@property (weak, nonatomic) IBOutlet UIImageView *img25;
@property (weak, nonatomic) IBOutlet UIImageView *img26;
@property (weak, nonatomic) IBOutlet UIImageView *img27;
@property (weak, nonatomic) IBOutlet UIImageView *img28;
@property (weak, nonatomic) IBOutlet UIImageView *img29;
@property (weak, nonatomic) IBOutlet UIImageView *img30;
@property (weak, nonatomic) IBOutlet UIImageView *img31;
@property (weak, nonatomic) IBOutlet UIImageView *img32;
@property (weak, nonatomic) IBOutlet UIImageView *img33;
@property (weak, nonatomic) IBOutlet UIImageView *img34;
@property (weak, nonatomic) IBOutlet UIImageView *img35;
@property (weak, nonatomic) IBOutlet UIImageView *img36;
@property (weak, nonatomic) IBOutlet UIImageView *img37;
@property (weak, nonatomic) IBOutlet UIImageView *img38;
@property (weak, nonatomic) IBOutlet UIImageView *img39;
@property (weak, nonatomic) IBOutlet UIImageView *img40;
@property (strong, nonatomic) NSArray *imageViews;

@property CGPoint *holder1;
@property CGPoint *holder2;
@property CGPoint *holder3;
@property CGPoint *holder4;
@property CGPoint *holder5;
@property CGPoint *holder6;
@property CGPoint *holder7;
@property CGPoint *holder8;
@property (strong, nonatomic) NSMutableArray *holders;

@end

.m file

#import "DSAAssignmentViewController2.h"

@interface DSAAssignmentViewController2 ()

@end

@implementation DSAAssignmentViewController2
@synthesize lblDisplayPreviousInput;
@synthesize imgOriginal;
@synthesize img1;
@synthesize img2;
@synthesize img3;
@synthesize img4;
@synthesize img5;
@synthesize img6;
@synthesize img7;
@synthesize img8;
@synthesize img9;
@synthesize img10;
@synthesize img11;
@synthesize img12;
@synthesize img13;
@synthesize img14;
@synthesize img15;
@synthesize img16;
@synthesize img17;
@synthesize img18;
@synthesize img19;
@synthesize img20;
@synthesize img21;
@synthesize img22;
@synthesize img23;
@synthesize img24;
@synthesize img25;
@synthesize img26;
@synthesize img27;
@synthesize img28;
@synthesize img29;
@synthesize img30;
@synthesize img31;
@synthesize img32;
@synthesize img33;
@synthesize img34;
@synthesize img35;
@synthesize img36;
@synthesize img37;
@synthesize img38;
@synthesize img39;
@synthesize img40;
@synthesize passedData;
@synthesize imageViews;

@synthesize holder1;
@synthesize holder2;
@synthesize holder3;
@synthesize holder4;
@synthesize holder5;
@synthesize holder6;
@synthesize holder7;
@synthesize holder8;
@synthesize holders;

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    // make jigsaw piece holders
    //create 8 points where the jigsaw pieces (images) will be placed
    CGPoint holder1 = CGPointMake(60, 644);
    CGPoint holder2 = CGPointMake(140, 644);
    CGPoint holder3 = CGPointMake(220, 644);
    CGPoint holder4 = CGPointMake(300, 644);
    CGPoint holder5 = CGPointMake(380, 644);
    CGPoint holder6 = CGPointMake(460, 644);
    CGPoint holder7 = CGPointMake(540, 644);
    CGPoint holder8 = CGPointMake(620, 644);

    // set up array of cgpoints
    holders = [NSMutableArray arrayWithObjects:[NSValue valueWithCGPoint: holder1],[NSValue valueWithCGPoint: holder2], [NSValue valueWithCGPoint: holder3], [NSValue valueWithCGPoint: holder4], [NSValue valueWithCGPoint: holder5], [NSValue valueWithCGPoint: holder6], [NSValue valueWithCGPoint: holder7], [NSValue valueWithCGPoint: holder8], nil];

    // set up array of images
    imageViews = [NSArray arrayWithObjects:img1, img2, img3, img4, img5, img6, img7, img8, img9, img10, img11, img12, img13, img14, img15, img16, img17, img18, img19, img20, img21, img22, img23, img24, img25, img26, img27, img28, img29, img30, img31, img32, img33, img34, img35, img36, img37, img38, img39, img40, nil];

    NSString *welcomeMessage = [NSString stringWithFormat:@"Welcome %@", passedData];
    UIAlertView *alert = [[UIAlertView alloc]   //show alert box with option to play or exit
                          initWithTitle: welcomeMessage 
                          message:@"Once you press \"Play\" the timer will start. Good luck!" 
                          delegate:self 
                          cancelButtonTitle:@"I want out!" 
                          otherButtonTitles:@"Play",nil];
    [alert show];
    NSLog(@"x-coord: %f, y-coord: %f", holder1.x, holder1.y);
}

-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
       UITouch *touch = [touches anyObject];
    //location of current touch
    CGPoint location = [touch locationInView:self.view];
    UIView *touchedView = [touch view];
    if ([imageViews indexOfObject:touchedView] != NSNotFound) {
        // not not found means found!
        [self animateFirstTouch:touchedView withLocation:location];
    } else {
        return;
    }

}

-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    [self touchesBegan:touches withEvent:event];
}


-(void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    //location of current touch
    CGPoint location = [touch locationInView:self.view];
    UIView *touchedView = [touch view];
    [self animateReleaseTouch:touchedView withLocation:location];

}



- (void)viewDidUnload
{
    [self setLblDisplayPreviousInput:nil];
    [self setImgOriginal:nil];
    [self setImg1:nil];
    [self setImg2:nil];
    [self setImg3:nil];
    [self setImg4:nil];
    [self setImg5:nil];
    [self setImg6:nil];
    [self setImg7:nil];
    [self setImg8:nil];
    [self setImg9:nil];
    [self setImg10:nil];
    [self setImg11:nil];
    [self setImg12:nil];
    [self setImg13:nil];
    [self setImg14:nil];
    [self setImg15:nil];
    [self setImg16:nil];
    [self setImg17:nil];
    [self setImg18:nil];
    [self setImg19:nil];
    [self setImg20:nil];
    [self setImg21:nil];
    [self setImg22:nil];
    [self setImg23:nil];
    [self setImg24:nil];
    [self setImg25:nil];
    [self setImg26:nil];
    [self setImg27:nil];
    [self setImg28:nil];
    [self setImg29:nil];
    [self setImg30:nil];
    [self setImg31:nil];
    [self setImg32:nil];
    [self setImg33:nil];
    [self setImg34:nil];
    [self setImg35:nil];
    [self setImg36:nil];
    [self setImg37:nil];
    [self setImg38:nil];
    [self setImg39:nil];
    [self setImg40:nil];
    [super viewDidUnload];
    // Release any retained subviews of the main view.
}

-(void) animateFirstTouch:(UIImageView *)image withLocation:(CGPoint)location {
    image.center = location;
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:0.2];
    image.transform = CGAffineTransformMakeScale(1.25, 1.25);  
    [UIView commitAnimations];   
}

-(void) animateReleaseTouch:(UIImageView *)image withLocation:(CGPoint)location {
    image.center = location;
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:0.2];
    image.transform = CGAffineTransformMakeScale(1.0, 1.0);  
    [UIView commitAnimations];   
}



- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

@end

I can't tell if its all a bit of a mess or not. As you can see i've started with only 8 "holders", these are the CGPoints that represent the center of where the jigsaw pieces should be placed.

Answer 1

borrrden is correct. You've created a whole bunch of CGPoint pointer variables by declaring them as properties and synthesizing them. But then in your -viewDidLoad method you're declaring CGPoint structs--not CGPoint pointers--all with the same name as the properties you synthesized.

You don't need the holderN properties at all, to judge from the code. In fact, you don't even need the holderN variables in the -viewDidLoad method. You could easily get away with something like this:

- ( void )viewDidLoad
{
    holders = [ NSMutableArray arrayWithObjects:
                               [ NSValue valueWithCGPoint: CGPointMake(60, 644) ],
                               ...,
                               [ NSValue valueWithCGPoint: CGPointMake(N, N) ],
                               nil ];
    ...
}

Hard-coding the point coordinates is poor design, though. Your best option is to put the coordinates in a plist, which you can load on demand and stuff into an array. This'll mean tweaking the coordinates is just a matter of editing the plist. No recompiling required.

Answer 2

之所以会在注释中得到该消息，是因为您在viewDidLoad的开头声明了与属性同名的变量。

Answer 3

NSPoint不是对象，因此您必须使用C数组： NSPoint points[SIZE]或使用NSValue容器： [NSValue valueWithCGPoint: point]