创建和循环布尔数组

Question

我正在创建一个拼图应用程序。当每块被触摸时，如果将其放在正确的位置，则将布尔 (droppedInPlace) 分配为 YES，如果将其放在错误的位置，则分配 NO。然后我想我需要创建一个包含 40 个布尔值（拼图块的数量）的数组，这些条目中的每一个最初都将设置为 NO。

然后使用replaceObjectAtIndex 将这个布尔值 (droppedInPlace) 插入到一个数组中。然后我想遍历这个数组。如果所有条目都是 true/yes/1，那么拼图就完成了，我将运行一些代码。

我在执行此操作时遇到了一些问题。我不知道如何在上面编写我的想法。以下是我的代码：

-(void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
UIView *touchedView = [touch view];
// filename to be read from
NSString *filePath = [[NSBundle mainBundle]
                      pathForResource: 
                      @"jigsawHomeCenterPoints" 
                      ofType:@"plist"];
// array of cgpoints in string format
NSArray *jigsawHomeCentersArray = [NSArray arrayWithContentsOfFile:filePath];
// the tag number of the selected image
int tag = touchedView.tag;
NSLog(@"tag: %i", tag);
// says that the piece has not been dropped in it's holder
bool droppedInPlace = NO;
// if what has been touched is part of the array of images
if ([imagesJigsawPieces indexOfObject:touchedView] != NSNotFound) {
    // preparing new snap-to-center position
    // using (tag-1) as an index in the HomeCentersArray corresponds to where the image should be placed
    // this was a conscious decision to make the process easier
    CGPoint newcenter = CGPointFromString([jigsawHomeCentersArray objectAtIndex:tag-1]);
    // the location of the current touch
    CGPoint location = [touch locationInView:self.view];
    // call the animate method upon release
    [self animateReleaseTouch:touchedView withLocation:location];
    // setting a proximity range - if it is within this 80x80 area the image will snap to it's corresponding holder (HomeCenter)
    if (location.x > newcenter.x-40 && location.x < newcenter.x+40 
        && location.y > newcenter.y-40 && location.y < newcenter.y+40) {
        touchedView.center = newcenter;
        touchedView.alpha = 1.0;
        droppedInPlace = YES;
    } else {
        touchedView.alpha = 0.5;
        droppedInPlace = NO;
    }
    NSLog(@"True or false: %i", droppedInPlace);
[self checkJigsawCompleted:droppedInPlace withTag:tag];
}
}

还有校验功能：

-(void) checkJigsawCompleted:(BOOL)inPlace withTag:(NSInteger)tag {
NSMutableArray *piecesInPlace;
[piecesInPlace replaceObjectAtIndex:tag-1 withObject:[NSNumber numberWithBool:inPlace]];
//code to loop through array - check if all entries are true/yes/1
//if so, jigsaw is completed - run some other code
//else, do nothing
}

Answer 1

请注意，您的 piecesInPlace 数组未在方法 checkJigsawCompleted 中初始化，将在下一行崩溃。

假设它用正确的值初始化，检查所有值是否为真的方法很简单：

for (NSNumber *boolNumber in piecesInPlace) {
    if (![boolNumber boolValue])
       return false;
}

return true;

编辑：或更好：

return ![piecesInPlace containsObject:[NSNumber numberWithBool:NO]];

Answer 2

您想知道如何遍历数组吗？您可以使用for(;;) 循环或for(.. in ..) 循环，或者，我最喜欢这种事情：-enumerateObjectsUsingBlock:

__block jigsawIsComplete = true;
[piecesInPlace enumerateObjectsUsingBlock: ^(id obj, NSUInteger i, BOOL* stop)
    {
        jigsawIsComplete = jigSawIsComplete && [obj boolValue];
        *stop = !jigsawIsComplete;
    }];

Answer 3

所以，有几件事。首先，您将根据拼图的标签替换这个piecesInPlace 可变数组中的对象，看起来像这样。但是，您永远不会设置这些视图的标签。所以，这一行：

int tag = touchedView.tag;

将始终为 0。更糟糕的是，您的 replaceObjectAtIndex:tag-1 位将尝试访问不合法的数组的 -1 索引（此时，但一旦 Apple 公开了一些更改）合法。

只要循环遍历数组并检查真值，我建议使用该方法

- (void)enumerateObjectsUsingBlock:(void (^)(id obj, NSUInteger idx, BOOL *stop))block

使用这个，只要在数组中找到 NO 值，就可以将停止指针设置为 YES，枚举将结束。只要停止为否，您只想继续枚举。如果你不停地通过你的数组，所有的值都是 YES。