ios - Arc4random 错误 : "Invalid operands to binary expression (' float' and 'float' )"

Question

我想在特定 View 中的随机位置创建一个按钮。我搜索并阅读了一些 SO 主题，但是找不到解决问题的方法。

这是我的代码:

UIButton *button1 = [UIButton buttonWithType:UIButtonTypeCustom];
CGRect buttonRect = button1.frame;
buttonRect.size = CGSizeMake(100, 100);
button1.frame = buttonRect;

[self.arr addObject:button1];

int r = ([button1 frame].size.width)/2;

int x = r + (arc4random() % (self.view.frame.size.width - button1.frame.size.width));
int y = r + (arc4random() % (self.view.frame.size.height - button1.frame.size.height));
//ERROR:Invalid operands to binary expression ('float' and 'float')

[button1 setCenter:CGPointMake(x, y)]; 

Answer 1

mod (%) 不适用于 float 。

int x = r + (arc4random() % (int)(self.view.frame.size.width - button1.frame.size.width));
int y = r + (arc4random() % (int)(self.view.frame.size.height - button1.frame.size.height));

---

作为附加说明，arc4random() % ... 是 not recommended .

这是首选方法:

int x = r + arc4random_uniform(self.view.frame.size.width - button1.frame.size.width);
int y = r + arc4random_uniform(self.view.frame.size.height - button1.frame.size.height);