五个按钮保持相等距离的圆形旋转

Question

我想在一个圆的圆周上旋转五个按钮（圆心（120,120），它实际上是方形视图的中心，即240 * 240），半径为100。可以这样做，通过与正在旋转的按钮以及适当的外观进行交互。

我曾尝试 '

x = round(cx + redious * cos(angl)); 
y = round(cy - redious * sin(angl)); 

NSString *X=[NSString stringWithFormat:@"%f",x]; 
[xval addObject:[NSString stringWithFormat:@"%@",X]]; 
NSString *Y=[NSString stringWithFormat:@"%f",y]; 
[yval addObject:[NSString stringWithFormat:@"%@",Y]];' 

计算分：

map.frame= CGRectMake([[fqx objectAtIndex:counter1]intValue],[[fqy objectAtIndex:counter1]intValue], 72, 37); 
website.frame= CGRectMake([[fqx objectAtIndex:counter2]intValue],[[fqy objectAtIndex:counter2]intValue], 72, 37); 
share.frame= CGRectMake([[fqx objectAtIndex:counter3]intValue],[[fqy objectAtIndex:counter3]intValue], 72, 37); 
slideShow.frame= CGRectMake([[fqx objectAtIndex:counter4]intValue],[[fqy objectAtIndex:counter4]intValue], 72, 37);' 

旋转，但它产生怪异的路径。在三角形的方式.. （' 地图”， '分享' ，'slideShow'，'website'）我的按钮..：P

Answer 1

这太可爱了，不能通过所以这里。此代码仅限于一个按钮旋转，但我怀疑你会遇到问题需要多次（提示：一次使用一个CADisplayLink并旋转所有按钮）。

- (void)setupRotatingButtons 
{ 
    // call this method once; make sure "self.view" is not nil or the button 
    // won't appear. the below variables are needed in the @interface. 
    // center: the center of rotation 
    // radius: the radius 
    // time: a CGFloat that determines where in the cycle the button is located at 
    //   (note: it will keep increasing indefinitely; you need to use 
    //   modulus to find a meaningful value for the current position, if 
    //   needed) 
    // speed: the speed of the rotation, where 2 * M_PI is 1 lap a second 
    // b:  the UIButton 
    center = CGPointMake(100, 100); 
    radius = 100; 
    time = 0; 
    speed = 2 * M_PI; // <-- will rotate CW 360 degrees per second (1 "lap"/s) 

    b = [[UIButton buttonWithType:UIButtonTypeRoundedRect] retain]; 
    b.titleLabel.text = @"Hi"; 
    b.frame = CGRectMake(0.f, 0.f, 100, 50); 
    // we get the center set right before we add subview, to avoid glitch at start 
    [self continueCircling:nil]; 
    [self.view addSubview:b]; 
    [self.view bringSubviewToFront:b]; 
    CADisplayLink *dl = [CADisplayLink displayLinkWithTarget:self 
     selector:@selector(continueCircling:)]; 
    [dl addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; 
} 

我们还需要实际的“continueCircling：”方法，这是简单的：

- (void)continueCircling:(CADisplayLink *)dl 
{ 
    time += speed * dl.duration; 
    b.center = CGPointMake(center.x + radius * cosf(time), 
          center.y + radius * sinf(time)); 
} 

我敢肯定有其他更漂亮的方式来解决这个问题，但至少上述作品。 :)

编辑：我忘了提，你将需要添加QuartzCore框架和

#import <QuartzCore/QuartzCore.h> 

的CADisplayLink。

编辑2：找到PI常数（M_PI），因此用3.1415代替。