为什么这只检测到精灵中心的触摸?

我尝试用以下代码让手指拖动ccsprite:

-(BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event {
    CGPoint location = [touch locationInView: [touch view]];
    CGPoint convertedCoordinate = [[CCDirector sharedDirector] convertToGL:location];

    CGRect redCircleRect = CGRectMake(redCircle.position.x, redCircle.position.y, redCircle.contentSize.width, redCircle.contentSize.height);
    CGRect redCircle2Rect = CGRectMake(redCircle2.position.x, redCircle2.position.y, redCircle2.contentSize.width, redCircle2.contentSize.height);

    if(CGRectContainsPoint(redCircleRect, convertedCoordinate)) {
        //redCircle.position = ccp(convertedCoordinate.x, convertedCoordinate.y);
        NSLog(@"Touched");
        spriteIndex = 1;
    }
    else if(CGRectContainsPoint(redCircle2Rect, convertedCoordinate)) {
        //redCircle2.position = ccp(convertedCoordinate.x, convertedCoordinate.y);
        NSLog(@"Touched2");
        spriteIndex = 2;
    }
    else {
        spriteIndex = 0;
    }
    return YES;
}
-(void)ccTouchMoved:(UITouch *)touch withEvent:(UIEvent *)event {
    CGPoint location = [touch locationInView: [touch view]];
    CGPoint convertedCoordinate = [[CCDirector sharedDirector] convertToGL:location];   

    if (spriteIndex == 1) {
        redCircle.position = ccp(convertedCoordinate.x, convertedCoordinate.y);
    }
    else if (spriteIndex == 2) {
        redCircle2.position = ccp(convertedCoordinate.x, convertedCoordinate.y);
    }

    //CGRect RedCircleRect = CGRectMake(redCircle.position.x, redCircle.position.y, redCircle.contentSize.width, redCircle.contentSize.height);
    //CGRect RedCircle2Rect = CGRectMake(redCircle.position.x, redCircle.position.y, redCircle.contentSize.width, redCircle.contentSize.height);

}

我的逻辑如下:

在 ccTouchesBegan 我得到了触摸的位置,将其转换为正确的坐标,然后制作两个CGRECT,假设它们与我声明的两个精灵的尺寸和位置相同。然后,我用 CGRectContainsPoint . 在那里,我有一个全局int spriteIndex 我根据接触到的圆指定一个值。

下一步,在 ccTouchesMoved 我检查是否 斯普利特指数 已经给出了我要移动的两个精灵中的一个的“索引”,如果是的话,将选中精灵的位置设置为触摸位置。

问题:

这个代码只起作用。它允许我拖动ccsprites,但仅当我单击中心时。sprite是40×40像素,所以它绝不是小的。