//可以去掉分割线
- (void)addSubview:(UIView *)view{
    if ([view isKindOfClass:NSClassFromString(@"_UITableViewCellSeparatorView")]) {
        return;
    }
    [super addSubview:view];
}

//改变cell的frame
- (void)setFrame:(CGRect)frame{
    /*
     左右距离 10 ，y+10，高度减少15
     */
    if (frame.size.height < 1) {//直接==0 在Xcode11下编译有bug
        [super setFrame:frame];
        return;
    }
    frame.origin.x = 15;
    frame.size.width -= 2 * frame.origin.x;
//    frame.origin.y += 10;
    frame.size.height -= 20;
    [super setFrame:frame];
}

//取消点击效果
[tableView deselectRowAtIndexPath:indexPath animated:YES];

//简单修改UITableViewHeaderFooterView的字体、颜色等
//新建个类继承UITableViewHeaderFooterView，然后在layoutSubviews里修改
- (void)layoutSubviews {
    [super layoutSubviews];
    
    self.textLabel.font = [UIFont boldSystemFontOfSize:18];
    if (@available(iOS 13.0, *)) {
        self.textLabel.textColor = [UIColor labelColor];
    } else {
        self.textLabel.textColor = [UIColor blackColor];
    }
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
   ...
    
    cell.preservesSuperviewLayoutMargins = NO;///>=iOS 8，子view和父view间有8个像素
    cell.layoutMargins = UIEdgeInsetsMake(0, 20, 0, 20);///>=iOS 8
    cell.separatorInset = UIEdgeInsetsMake(0, 20, 0, 20);///<=iOS 7,默认距左15
    
    return cell;
}