isKindOfClass不起作用

Question

我正在创建一个游戏，其中行和列中的一定数量的块从屏幕顶部落下并落在地板上。当玩家触摸某种颜色的块时，该块以及相同颜色的相邻块被移除。我的

有问题

if ([touchedNode isKindOfClass: [BlockSpriteNode class]]){}

出于某种原因，如果我将此if语句留在其中，则在单击时不会删除块。但是，如果我将其删除或执行

if(YES){}

然后它的工作原理。这是我的方法：

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{

/* Called when a touch begins */

    UITouch * touch = [touches anyObject];

    CGPoint location = [touch locationInNode:self];

    //ensure that touches are acknowledged and shows where on the screen the touch happened
    NSLog(@"Screen has been touched @(%f, %f) ", location.x, location.y);

    //get the object that was touched
    SKSpriteNode * touchedNode = (SKSpriteNode *) [self nodeAtPoint:location];

    //ensure a BlockSpriteNode was touched
    if ([touchedNode isKindOfClass: [BlockSpriteNode class]])
    {
        //debug to check that i hit a block
        NSLog(@"you touched a block");

        //cast the touched item in BlockSpriteNode
        BlockSpriteNode * touchedBlock = (BlockSpriteNode *)touchedNode;

        //remove a block from the scene
        [touchedBlock removeFromParent];

    }
}