result 的值變化範圍是 0 - valueRange / 2, valueRange / 2 - 0, 0 - valueRange / 2, valueRange / 2 - 0;
static int rote = 0;
int valueRange = 20;
int maxValue = valueRange / 2;
int a = rote % valueRange;
int b = rote / maxValue;
int c = b % 2;
int result = (valueRange * c + a * (pow(-1, c)));
rote++;
result 的值變化範圍是 0 - valueRange, 0 - valueRange, 0 - valueRange, 0 - valueRange;
static int rote = 0;
int valueRange = 20;
int result = (rote % valueRange );
rote++;
scorllView的子view的佈局
NSArray <UIView *> * viewsArray;
UIScrollView *scrollView;
__block UIView *lastView = scrollView;
[viewsArray enumerateObjectsUsingBlock:^(UIView * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
[obj mas_makeConstraints:^(MASConstraintMaker *make) {
MASViewAttribute * mas_ori = (idx == 0) ? lastView.mas_left : lastView.mas_right;
make.left.equalTo(mas_ori).offset(5);
make.top.bottom.equalTo(scrollView);
if (idx == viewsArray.count - 1) make.right.equalTo(scrollView);
}];
lastView = obj;
}];