UITableView Section增加圆角

先上效果图:
image.png
因为有的section里面有HeaderView有的没有HeaderView,所以切图角的时候需要判断这种情况.
圆角直接用的layer的mask实现
OK,直接上代码吧:
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
    //圆率
    CGFloat cornerRadius = 8;
    //大小
    CGRect bounds = cell.bounds;
    //行数
    NSInteger numberOfRows = [tableView numberOfRowsInSection:indexPath.section];
    UIView *headerView;
    if ([self respondsToSelector:@selector(tableView:viewForHeaderInSection:)]) {
        headerView=[self tableView:tableView viewForHeaderInSection:indexPath.section];
    }
    
    //绘制曲线
    UIBezierPath *bezierPath = nil;
    if (headerView) {
        if (indexPath.row == 0 && numberOfRows == 1) {
            //一个为一组时，四个角都为圆角
            bezierPath = [UIBezierPath bezierPathWithRoundedRect:bounds byRoundingCorners:(UIRectCornerBottomLeft|UIRectCornerBottomRight) cornerRadii:CGSizeMake(cornerRadius, cornerRadius)];
        }else
        if (indexPath.row == numberOfRows - 1) {
            //为组的最后一行，左下、右下角为圆角
            bezierPath = [UIBezierPath bezierPathWithRoundedRect:bounds byRoundingCorners:(UIRectCornerBottomLeft|UIRectCornerBottomRight) cornerRadii:CGSizeMake(cornerRadius, cornerRadius)];
        } else {
            //中间的都为矩形
            bezierPath = [UIBezierPath bezierPathWithRect:bounds];
        }
    }else{
        if (indexPath.row == 0 && numberOfRows == 1) {
            //一个为一组时，四个角都为圆角
            bezierPath = [UIBezierPath bezierPathWithRoundedRect:bounds byRoundingCorners:UIRectCornerAllCorners cornerRadii:CGSizeMake(cornerRadius, cornerRadius)];
        } else if (indexPath.row == 0) {
            //为组的第一行时，左上、右上角为圆角
            bezierPath = [UIBezierPath bezierPathWithRoundedRect:bounds byRoundingCorners:(UIRectCornerTopLeft|UIRectCornerTopRight) cornerRadii:CGSizeMake(cornerRadius, cornerRadius)];
        } else if (indexPath.row == numberOfRows - 1) {
            //为组的最后一行，左下、右下角为圆角
            bezierPath = [UIBezierPath bezierPathWithRoundedRect:bounds byRoundingCorners:(UIRectCornerBottomLeft|UIRectCornerBottomRight) cornerRadii:CGSizeMake(cornerRadius, cornerRadius)];
        } else {
            //中间的都为矩形
            bezierPath = [UIBezierPath bezierPathWithRect:bounds];
        }
    }
    
    //新建一个图层
    CAShapeLayer *layer = [CAShapeLayer layer];
    //图层边框路径
    layer.path = bezierPath.CGPath;
    cell.layer.mask=layer;
}

- (void)tableView:(UITableView *)tableView willDisplayHeaderView:(UIView *)view forSection:(NSInteger)section {
    //圆率
    CGFloat cornerRadius = 8;
    //大小
    CGRect bounds = view.bounds;
    
    //绘制曲线
    UIBezierPath *bezierPath = nil;
    //为组的第一行时，左上、右上角为圆角
    bezierPath = [UIBezierPath bezierPathWithRoundedRect:bounds byRoundingCorners:(UIRectCornerTopLeft|UIRectCornerTopRight) cornerRadii:CGSizeMake(cornerRadius, cornerRadius)];
    //新建一个图层
    CAShapeLayer *layer = [CAShapeLayer layer];
    //图层边框路径
    layer.path = bezierPath.CGPath;
    view.layer.mask=layer;
}