在Swift中你可以使用这个

    cell.selectionStyle = UITableViewCellSelectionStyle.None
    cell.preservesSuperviewLayoutMargins = false
    cell.separatorInset = UIEdgeInsetsZero
    cell.layoutMargins = UIEdgeInsetsZero

这在我的iOS 8和iOS 9系统中运行得非常好。

对于OBJ-C

 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath  { 
        if ([tableView respondsToSelector:@selector(setSeparatorInset:)])
        {
            [tableView setSeparatorInset:UIEdgeInsetsZero];
        }

        if ([tableView respondsToSelector:@selector(setLayoutMargins:)])
        {
            [tableView setLayoutMargins:UIEdgeInsetsZero];
        }

        if ([cell respondsToSelector:@selector(setLayoutMargins:)])
        {
            [cell setLayoutMargins:UIEdgeInsetsZero];
        }
         return cell;
    }

对我来说，简单的线条就够了

cell.layoutMargins = UIEdgeInsetsZero

在Swift中你可以使用这个

    cell.selectionStyle = UITableViewCellSelectionStyle.None
    cell.preservesSuperviewLayoutMargins = false
    cell.separatorInset = UIEdgeInsetsZero
    cell.layoutMargins = UIEdgeInsetsZero

对我来说，除了这个解决方案(Swift 3.0)之外，其他方法都不起作用:

extension UIColor {
    static func colorWith(hex:String, alpha: CGFloat) -> UIColor {
        var cString = hex.trimmingCharacters(in: .whitespacesAndNewlines).uppercased()

        if cString.hasPrefix("#") {
            cString.remove(at: cString.startIndex)
        }

        if cString.characters.count != 6 {
            return UIColor.gray
        }

        var rgbValue:UInt32 = 0
        Scanner(string: cString).scanHexInt32(&rgbValue)

        return UIColor(red:   CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0,
                       green: CGFloat((rgbValue & 0x00FF00) >> 8)  / 255.0,
                       blue:  CGFloat( rgbValue & 0x0000FF)        / 255.0,
                       alpha: alpha)
    }
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: cellReuseIdendifier, for: indexPath)

    cell.backgroundColor = UIColor.colorWith(hex: "c8c7cc", alpha: 1) // same color of line separator

    return cell
}

Arg ! !在你的Cell子类中做这些事情后:

- (UIEdgeInsets)layoutMargins
{
    return UIEdgeInsetsZero;
}

或者设置单元格。layoutmargin = UIEdgeInsetsZero;帮我修好了。