Objective-C索引數組

Question

我正在基於火種的刷卡功能構建一個（玩笑）應用程序，使我能夠保持“魔術聚會”游戲的得分。

過去，我只是通過將數字作為字符串遞增和遞減來完成此操作。 這很好。

現在，我使用Richard Kim的TinderSimpleSwipeCards ，它從帶有整數的數組中加載卡片。 刷卡時，有一種方法稱為在陣列中加載下一個數字。 作為Objective-C的新手，我花了一個小時嘗試根據我的需要重新調整陣列的用途。 但是我被困住了。

由於玩家可以在“魔法聚會”中獲得或失去生命，因此我的目標是能夠首先加載20，然后向右輕掃以增加數字，向左輕掃以減少數字（降低為0）。

我的第一個想法是創建一個包含40個數字的數組，然后使該方法從索引20開始，從而將整數20加載到卡中。然后，通過向任一方向調用該方法，可以將卡加載為正數或負面的方向。

但這沒有用。

這是Richard的DraggableViewBackground.m文件。 他在-（void）loadCards中調用該方法，這是我一直在嘗試處理索引號的地方。

我相當肯定這不能通過使用數組來完成，方法是簡單地從中間的索引開始，然后在（i-1）或（i + 1）方向上運行For循環。 當我確實在特定索引號處調用對象時，該方法將繼續在該索引處創建卡（例如，如果我創建了DragDraggableViewWithDataAtIndex：4，則新卡為16-數組中的第五項將繼續加載帶有16的卡片）。

有人可以確認使用單個陣列可以或不能完成此操作嗎？ 如果可以的話，有人可以指導我如何從正確的索引裝入卡嗎？

 //
//  DraggableViewBackground.m
//  testing swiping
//
//  Created by Richard Kim on 8/23/14.
//  Copyright (c) 2014 Richard Kim. All rights reserved.
//

#import "DraggableViewBackground.h"

@implementation DraggableViewBackground{
    NSInteger cardsLoadedIndex; //%%% the index of the card you have loaded into the loadedCards array last
    NSMutableArray *loadedCards; //%%% the array of card loaded (change max_buffer_size to increase or decrease the number of cards this holds)

    UIButton* menuButton;
    UIButton* messageButton;
    UIButton* checkButton;
    UIButton* xButton;
}
//this makes it so only two cards are loaded at a time to
//avoid performance and memory costs
static const int MAX_BUFFER_SIZE = 2; //%%% max number of cards loaded at any given time, must be greater than 1
static const float CARD_HEIGHT = 200; //%%% height of the draggable card
static const float CARD_WIDTH = 290; //%%% width of the draggable card

@synthesize exampleCardLabels; //%%% all the labels I'm using as example data at the moment
@synthesize allCards;//%%% all the cards

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        [super layoutSubviews];
        [self setupView];
        exampleCardLabels = [[NSArray alloc]initWithObjects:@"20",@"19",@"18",@"17",@"16",@"15",@"14",@"13",@"12",@"11",@"10",@"9",@"8",@"7",@"6",@"5",@"4",@"3",@"2",@"1",@"DEATH", nil]; //%%% placeholder for card-specific information
        loadedCards = [[NSMutableArray alloc] init];
        allCards = [[NSMutableArray alloc] init];
        cardsLoadedIndex = 0;

        [self loadCards];
    }
    return self;
}

//%%% sets up the extra buttons on the screen
-(void)setupView
{
#warning customize all of this.  These are just place holders to make it look pretty
    self.backgroundColor = [UIColor colorWithRed:.92 green:.93 blue:.95 alpha:1]; //the gray background colors
    menuButton = [[UIButton alloc]initWithFrame:CGRectMake(17, 34, 22, 15)];
    [menuButton setImage:[UIImage imageNamed:@"menuButton"] forState:UIControlStateNormal];
    messageButton = [[UIButton alloc]initWithFrame:CGRectMake(284, 34, 18, 18)];
    [messageButton setImage:[UIImage imageNamed:@"messageButton"] forState:UIControlStateNormal];
    xButton = [[UIButton alloc]initWithFrame:CGRectMake(60, 485, 59, 59)];
    [xButton setImage:[UIImage imageNamed:@"xButton"] forState:UIControlStateNormal];
    [xButton addTarget:self action:@selector(swipeLeft) forControlEvents:UIControlEventTouchUpInside];
    checkButton = [[UIButton alloc]initWithFrame:CGRectMake(200, 485, 59, 59)];
    [checkButton setImage:[UIImage imageNamed:@"checkButton"] forState:UIControlStateNormal];
    [checkButton addTarget:self action:@selector(swipeRight) forControlEvents:UIControlEventTouchUpInside];
    [self addSubview:menuButton];
    [self addSubview:messageButton];
    [self addSubview:xButton];
    [self addSubview:checkButton];
}

#warning include own card customization here!
//%%% creates a card and returns it.  This should be customized to fit your needs.
// use "index" to indicate where the information should be pulled.  If this doesn't apply to you, feel free
// to get rid of it (eg: if you are building cards from data from the internet)
-(DraggableView *)createDraggableViewWithDataAtIndex:(NSInteger)index
{
    DraggableView *draggableView = [[DraggableView alloc]initWithFrame:CGRectMake((self.frame.size.width - CARD_WIDTH)/2, (self.frame.size.height - CARD_HEIGHT)/2, CARD_WIDTH, CARD_HEIGHT)];
    draggableView.information.text = [exampleCardLabels objectAtIndex:index]; //%%% placeholder for card-specific information
    draggableView.delegate = self;
    return draggableView;
}

//%%% loads all the cards and puts the first x in the "loaded cards" array
-(void)loadCards
{
    if([exampleCardLabels count] > 0) {
        NSInteger numLoadedCardsCap =(([exampleCardLabels count] > MAX_BUFFER_SIZE)?MAX_BUFFER_SIZE:[exampleCardLabels count]);
        //%%% if the buffer size is greater than the data size, there will be an array error, so this makes sure that doesn't happen

        //%%% loops through the exampleCardsLabels array to create a card for each label.  This should be customized by removing "exampleCardLabels" with your own array of data
        for (int i = 0; i<[exampleCardLabels count]; i++) {


            DraggableView* newCard = [self createDraggableViewWithDataAtIndex:i];
            [allCards addObject:newCard];

            if (i<numLoadedCardsCap) {
                //%%% adds a small number of cards to be loaded
                [loadedCards addObject:newCard];
            }
        }

        //%%% displays the small number of loaded cards dictated by MAX_BUFFER_SIZE so that not all the cards
        // are showing at once and clogging a ton of data
        for (int i = 0; i<[loadedCards count]; i++) {
            if (i>0) {
                [self insertSubview:[loadedCards objectAtIndex:i] belowSubview:[loadedCards objectAtIndex:i-1]];
            } else {
                [self addSubview:[loadedCards objectAtIndex:i]];
            }
            cardsLoadedIndex++; //%%% we loaded a card into loaded cards, so we have to increment
        }
    }
}

#warning include own action here!
//%%% action called when the card goes to the left.
// This should be customized with your own action
-(void)cardSwipedLeft:(UIView *)card;
{
    //do whatever you want with the card that was swiped
    //    DraggableView *c = (DraggableView *)card;

    [loadedCards removeObjectAtIndex:0]; //%%% card was swiped, so it's no longer a "loaded card"

    if (cardsLoadedIndex < [allCards count]) { //%%% if we haven't reached the end of all cards, put another into the loaded cards
        [loadedCards addObject:[allCards objectAtIndex:cardsLoadedIndex]];
        cardsLoadedIndex++;//%%% loaded a card, so have to increment count
        [self insertSubview:[loadedCards objectAtIndex:(MAX_BUFFER_SIZE-1)] belowSubview:[loadedCards objectAtIndex:(MAX_BUFFER_SIZE-2)]];
    }
}

#warning include own action here!
//%%% action called when the card goes to the right.
// This should be customized with your own action
-(void)cardSwipedRight:(UIView *)card
{
    //do whatever you want with the card that was swiped
    //    DraggableView *c = (DraggableView *)card;

    [loadedCards removeObjectAtIndex:0]; //%%% card was swiped, so it's no longer a "loaded card"

    if (cardsLoadedIndex < [allCards count]) { //%%% if we haven't reached the end of all cards, put another into the loaded cards
        [loadedCards addObject:[allCards objectAtIndex:cardsLoadedIndex]];
        cardsLoadedIndex++;//%%% loaded a card, so have to increment count
        [self insertSubview:[loadedCards objectAtIndex:(MAX_BUFFER_SIZE-1)] belowSubview:[loadedCards objectAtIndex:(MAX_BUFFER_SIZE-2)]];
    }

}

//%%% when you hit the right button, this is called and substitutes the swipe
-(void)swipeRight
{
    DraggableView *dragView = [loadedCards firstObject];
    dragView.overlayView.mode = GGOverlayViewModeRight;
    [UIView animateWithDuration:0.2 animations:^{
        dragView.overlayView.alpha = 1;
    }];
    [dragView rightClickAction];
}

//%%% when you hit the left button, this is called and substitutes the swipe
-(void)swipeLeft
{
    DraggableView *dragView = [loadedCards firstObject];
    dragView.overlayView.mode = GGOverlayViewModeLeft;
    [UIView animateWithDuration:0.2 animations:^{
        dragView.overlayView.alpha = 1;
    }];
    [dragView leftClickAction];
}

/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    // Drawing code
}
*/

@end

Answer 1

如果我對您的理解正確，則不需要數組。 我會將卡的當前索引保存為整數值，並通過檢查范圍來增加和減少它的方法。 已經有一個ivar NSInteger cardsLoadedIndex;

在我看來，這樣的方法會起作用：

- (NSUInteger) getIndexDirectionRight:(BOOL)direction{
    if (direction){
        return (cardsLoadedIndex < MAX_VALUE) ? cardsLoadedIndex + 1 : 0;
    }else{
        return (cardsLoadedIndex > 0) ? cardsLoadedIndex - 1 : MAX_VALUE;
    }
}

您可以在swipeRight或swipeLeft調用該方法，並在initWithFrame方法中將cardsLoadedIndex初始化為20（因為它已經設置為0）。