scrollview技巧

一行

    CGFloat buttonX = 0;
    CGFloat buttonY = 25;
    CGFloat buttonW = 37;
    CGFloat buttonH = 60;
    CGFloat margin = (self.view.width - 6 * buttonW) / 7;
    for (int i = 0; i < self.countryArr.count; i++) {
        YTBottomTitleButton *button = self.countryArr[i];
        buttonX = margin + (buttonW + margin) * i;
        button.frame = CGRectMake(buttonX, buttonY, buttonW, buttonH);
    }
    self.countryScrollView.contentSize = CGSizeMake(self.countryArr.count * (buttonW + margin) + margin, 0);

两行

    buttonX = 0;
    buttonY = 25;
    buttonW = 50;
    buttonH = 20;
    NSInteger viewCount = 5;//一行view数量
    margin = (self.view.width - viewCount * buttonW) / 6;//左右间距
    CGFloat ymargin = 17;//上下间距
    NSInteger pageViewCount = 0;//一页view数量
    if (self.view.width > 320) {//iPhone6 or later
        pageViewCount = 20;
    }
    else {
        pageViewCount = 15;
    }
    for (int i = 0; i < self.platformArr.count; i++) {
        YTBottomTitleButton *button = self.platformArr[i];
        buttonX = margin +  (i % viewCount == 0 ? 0 : (buttonW + margin) * (i % viewCount)) + (i % pageViewCount == 0 ? ZWScreenW * i / pageViewCount : ZWScreenW * (i - i % pageViewCount) / pageViewCount);
        buttonY = i % viewCount == 0 ? (i % pageViewCount == 0 ? ymargin : ymargin + (buttonH + ymargin) * ((i % pageViewCount) / viewCount)) : buttonY;
        
        button.frame = CGRectMake(buttonX, buttonY, buttonW, buttonH);
    }
    
    NSInteger offset = self.platformArr.count > pageViewCount ? (self.platformArr.count % pageViewCount == 0 ? self.platformArr.count / 20 : self.platformArr.count / pageViewCount + 1) : 0;
    self.platformScrollView.contentSize = CGSizeMake(offset * ZWScreenW, 0);