Masonry的流式布局

gistfile1.txt

/// 实现流式按钮布局，自定义View如果支持sizeToFit，则也可以使用
/// @param superView 按钮将要放在的容器
/// @param buttons 按钮数组
/// @param horSpacing 横向间隔
/// @param verSpacing 行间隔
/// @param lineHeight 行高 其实可以按照sizeToFit后的数据
/// @param superViewWidth 这个是唯一的需要提前计算的点，不过也不会太复杂
- (void)buttonFlowView:(UIView *)superView
               buttons:(NSArray<UIButton *> *)buttons
            horSpacing:(CGFloat)horSpacing
            verSpacing:(CGFloat)verSpacing
            lineHeight:(CGFloat)lineHeight
        superViewWidth:(CGFloat)superViewWidth {

    // 定义一个变量来跟踪当前行中已经添加了多少个按钮
    CGFloat currentRowWidth = 0;
    [superView removeAllSubViews];
    //计算最小的button尺寸
    for (UIButton *button in buttons) {
        [superView addSubview:button];
        [button sizeToFit];
    }

    CGFloat currentRow = 0;

    NSMutableArray<NSMutableArray<UIButton *> *> *buttonsSubArray = [NSMutableArray<NSMutableArray<UIButton *> *> new];
    NSMutableArray<UIButton *> *lineArray = [NSMutableArray<UIButton *> new];
    for (UIButton *button in buttons) {
        CGFloat buttonWidth = button.frame.size.width;

        // 如果加上了这个按钮 已经不够空间了 则换行
        if (currentRowWidth + horSpacing + buttonWidth > superViewWidth) {  // 重置计数器 换行
            currentRowWidth = 0;
            currentRow++;
            [buttonsSubArray addObject:lineArray];
            lineArray = [NSMutableArray<UIButton *> new];
            [lineArray addObject:button];
        } else {
            [lineArray addObject:button];
        }

        if (buttons.lastObject == button) {
            [buttonsSubArray addObject:lineArray];
        }
        // 更新计数器
        currentRowWidth += horSpacing + buttonWidth;
    }

    currentRow = 0;
    CGFloat fullHeight = 0;
    for (NSMutableArray<UIButton *> *buttonLine in buttonsSubArray) {
        if (buttonLine.count < 2) {
            [buttonLine mas_makeConstraints:^(MASConstraintMaker *make) {
                make.top.mas_equalTo(superView).offset(currentRow * lineHeight + currentRow * verSpacing);
                make.height.offset(lineHeight);
                make.left.mas_equalTo(superView);
                make.right.mas_equalTo(superView);
            }];
        } else {
            [buttonLine mas_distributeViewsAlongAxis:MASAxisTypeHorizontal
                                    withFixedSpacing:horSpacing //横向间隔
                                         leadSpacing:0
                                         tailSpacing:0];

            [buttonLine mas_makeConstraints:^(MASConstraintMaker *make) {
                make.top.mas_equalTo(superView).offset(currentRow * lineHeight + currentRow * verSpacing);
                make.height.offset(lineHeight);
                //make.left.mas_equalTo(superView);
                //make.right.mas_equalTo(superView);
            }];

        }

        fullHeight += verSpacing + lineHeight;

        currentRow++;

        if (buttonsSubArray.lastObject == buttonLine) {
            [superView mas_updateConstraints:^(MASConstraintMaker *make) {
                make.bottom.mas_equalTo(buttonsSubArray.lastObject);
            }];
        }
    }
}