Question

我有10只萤火虫，我使用下面的代码在屏幕上“飞”。该代码还用于将萤火虫保持在屏幕上。

- (void)viewDidLoad
{
    [super viewDidLoad];

NSArray *blueArray = [NSArray array];
blueArray = [[NSArray alloc] initWithObjects:
             [UIImage imageNamed:@"blue1.png"],
             [UIImage imageNamed:@"blue2.png"], nil];

blue.animationImages = blueArray;
blue.animationDuration = 0.20;
blue.animationRepeatCount = -1;
[blue startAnimating]; 

    bluepos =CGPointMake(2.0, 1.5);
}


-(void) someMethod {
    endingAnimationTimer = [NSTimer scheduledTimerWithTimeInterval:(0.03) target:self selector:@selector(makeFly) userInfo:nil repeats:YES];
}


-(void) makeFly {

    blue.center = CGPointMake(blue.center.x+bluepos.x, blue.center.y+bluepos.y);{
        if(blue.center.x > 480 || blue.center.x <0)
            bluepos.x = -bluepos.x;

        if(blue.center.y > 320 || blue.center.y <0)
            bluepos.y = -bluepos.y;
    }
}

“飞行”效果很好，除了当萤火虫撞到屏幕边缘并反转方向以使它们保持在屏幕上时，萤火虫图像本身仍然“面向”其他方向，所以看起来它们向后飞了一半时间。

我想进行设置，以便当萤火虫撞到屏幕边缘时，它们会反转方向并且图像本身会反转。

我试过了：

在.h

@property (nonatomic, assign) BOOL blueIsFacingRight;

在.m

 @synthesize blueIsFacingRight;


-(void) makeFly {

    blue.center = CGPointMake(blue.center.x+bluepos.x, blue.center.y+bluepos.y); {
        if(blue.center.x > 480 ) {
            if (blueIsFacingRight == YES) {
                blue.transform = CGAffineTransformMakeScale(-1, 1);
                blueIsFacingRight = NO;
            }
            bluepos.x = -bluepos.x;


        }

        if(blue.center.x <0) {
            bluepos.x = -bluepos.x;

            if (blueIsFacingRight == NO) {
                blue.transform = CGAffineTransformMakeScale(1, 1);
                blueIsFacingRight = YES;
            }
        }

        if(blue.center.y > 320 )
            bluepos.y = -bluepos.y;

        if( blue.center.y <0)
            bluepos.y = -bluepos.y;
    }
}

我认为这会有效，但是当它撞到“墙”时图像不会反转

任何人都可以解释为什么这不起作用，如果有更好的原因可以实现我正在寻找的效果？

enter image description here

Answer 1

在两种情况下，您都将变换X值设置为-1。当它面向右边时，你应该设置像这样的CGAffineTransformMakeScale（1,1）;

blue.center = CGPointMake(blue.center.x+bluepos.x, blue.center.y+bluepos.y); {
if(blue.center.x > 480 ) {
    if (blueIsFacingRight == YES) {
        blue.transform = CGAffineTransformMakeScale(-1, 1);
        blueIsFacingRight = NO;
    }
    bluepos.x = -bluepos.x;


}

if(blue.center.x <0) {
    bluepos.x = -bluepos.x;

    if (blueIsFacingRight == NO) {
        blue.transform = CGAffineTransformMakeScale(1, 1);
        blueIsFacingRight = YES;
    }
}

Answer 2

**blue.transform =CGAffineTransformIdentity;**

上面是我的makeFly方法，上面有一堆其他东西，我正在反转图像，所以我在下次调用该方法时撤消了更改（0.03以后）

男人我感到愚蠢

在iOS中触及屏幕边缘时转换图像

2 个答案: