你必须采取自定义单元格，并添加标签和设置约束，如标签应覆盖整个单元格区域。 并在构造函数中编写下面的行。

- (void)awakeFromNib {
    // Initialization code
    self.separatorInset = UIEdgeInsetsMake(0, 10000, 0, 0);
    //self.layoutMargins = UIEdgeInsetsZero;
    [self setBackgroundColor:[UIColor clearColor]];
    [self setSelectionStyle:UITableViewCellSelectionStyleNone];
}

也设置UITableView布局边距如下

tblSignup.layoutMargins = UIEdgeInsetsZero;

实现这一点的最好方法是关闭默认的行分隔符，子类UITableViewCell，并添加一个自定义的行分隔符作为contentView的子视图-参见下面的自定义单元格，用于表示一个SNStock类型的对象，它有两个字符串属性，ticker和name:

import UIKit

private let kSNStockCellCellHeight: CGFloat = 65.0
private let kSNStockCellCellLineSeparatorHorizontalPaddingRatio: CGFloat = 0.03
private let kSNStockCellCellLineSeparatorBackgroundColorAlpha: CGFloat = 0.3
private let kSNStockCellCellLineSeparatorHeight: CGFloat = 1

class SNStockCell: UITableViewCell {

  private let primaryTextColor: UIColor
  private let secondaryTextColor: UIColor

  private let customLineSeparatorView: UIView

  var showsCustomLineSeparator: Bool {
    get {
      return !customLineSeparatorView.hidden
    }
    set(showsCustomLineSeparator) {
      customLineSeparatorView.hidden = !showsCustomLineSeparator
    }
  }

  var customLineSeparatorColor: UIColor? {
   get {
     return customLineSeparatorView.backgroundColor
   }
   set(customLineSeparatorColor) {
     customLineSeparatorView.backgroundColor = customLineSeparatorColor?.colorWithAlphaComponent(kSNStockCellCellLineSeparatorBackgroundColorAlpha)
    }
  }

  required init(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
  }

  init(reuseIdentifier: String, primaryTextColor: UIColor, secondaryTextColor: UIColor) {
    self.primaryTextColor = primaryTextColor
    self.secondaryTextColor = secondaryTextColor
    self.customLineSeparatorView = UIView(frame:CGRectZero)
    super.init(style: UITableViewCellStyle.Subtitle, reuseIdentifier:reuseIdentifier)
    selectionStyle = UITableViewCellSelectionStyle.None
    backgroundColor = UIColor.clearColor()

    contentView.addSubview(customLineSeparatorView)
    customLineSeparatorView.hidden = true
  }

  override func prepareForReuse() {
    super.prepareForReuse()
    self.showsCustomLineSeparator = false
  }

  // MARK: Layout

  override func layoutSubviews() {
    super.layoutSubviews()
    layoutCustomLineSeparator()
  }

  private func layoutCustomLineSeparator() {
    let horizontalPadding: CGFloat = bounds.width * kSNStockCellCellLineSeparatorHorizontalPaddingRatio
    let lineSeparatorWidth: CGFloat = bounds.width - horizontalPadding * 2;
    customLineSeparatorView.frame = CGRectMake(horizontalPadding,
      kSNStockCellCellHeight - kSNStockCellCellLineSeparatorHeight,
      lineSeparatorWidth,
      kSNStockCellCellLineSeparatorHeight)
  }

  // MARK: Public Class API

  class func cellHeight() -> CGFloat {
    return kSNStockCellCellHeight
  }

  // MARK: Public API

  func configureWithStock(stock: SNStock) {
    textLabel!.text = stock.ticker as String
    textLabel!.textColor = primaryTextColor
    detailTextLabel!.text = stock.name as String
    detailTextLabel!.textColor = secondaryTextColor
    setNeedsLayout()
  } 
}

要禁用默认的行分隔符，请使用tableView。separatorStyle = UITableViewCellSeparatorStyle.None;消费者方面相对简单，见下面的例子:

private func stockCell(tableView: UITableView, indexPath:NSIndexPath) -> UITableViewCell {
  var cell : SNStockCell? = tableView.dequeueReusableCellWithIdentifier(stockCellReuseIdentifier) as? SNStockCell
  if (cell == nil) {
    cell = SNStockCell(reuseIdentifier:stockCellReuseIdentifier, primaryTextColor:primaryTextColor, secondaryTextColor:secondaryTextColor)
  }
  cell!.configureWithStock(stockAtIndexPath(indexPath))
  cell!.showsCustomLineSeparator = true
  cell!.customLineSeparatorColor = tintColor
  return cell!
}

试试下面的代码，也许能帮你解决问题

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

   NSString* reuseIdentifier = @"Contact Cell";

    UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:reuseIdentifier];
    if (nil == cell) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:reuseIdentifier];
if (indexPath.row != 10) {//Specify the cell number
        cell.backgroundView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"bgWithLine.png"]];

} else {
        cell.backgroundView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"bgWithOutLine.png"]];

}

    }

    return cell;
}

在使用iOS 8.4的Swift中:

/*
    Tells the delegate that the table view is about to draw a cell for a particular row. (optional)
*/
override func tableView(tableView: UITableView,
                        willDisplayCell cell: UITableViewCell,
                        forRowAtIndexPath indexPath: NSIndexPath)
{
    if indexPath.row == 3 {
        // Hiding separator line for only one specific UITableViewCell
        cell.separatorInset = UIEdgeInsetsMake(0, cell.bounds.size.width, 0, 0)
    }
}

Note: this snippet above will work on UITableView using dynamic cells. The only problem that you can encounter is when you use static cells with categories, a separator type different than none and a grouped style for the table view. In fact, in this particular case it will not hide the last cell of each category. For overcoming that, the solution that I found was to set the cell separator (through IB) to none and then creating and adding manually (through code) your line view to each cell. For an example, please check the snippet below:

/*
Tells the delegate that the table view is about to draw a cell for a particular row. (optional)
*/
override func tableView(tableView: UITableView,
    willDisplayCell cell: UITableViewCell,
    forRowAtIndexPath indexPath: NSIndexPath)
{
    // Row 2 at Section 2
    if indexPath.row == 1 && indexPath.section == 1 {
        // Hiding separator line for one specific UITableViewCell
        cell.separatorInset = UIEdgeInsetsMake(0, cell.bounds.size.width, 0, 0)

        // Here we add a line at the bottom of the cell (e.g. here at the second row of the second section).
        let additionalSeparatorThickness = CGFloat(1)
        let additionalSeparator = UIView(frame: CGRectMake(0,
            cell.frame.size.height - additionalSeparatorThickness,
            cell.frame.size.width,
            additionalSeparatorThickness))
        additionalSeparator.backgroundColor = UIColor.redColor()
        cell.addSubview(additionalSeparator)
    }
}

在iOS9上，我有一个问题，改变分隔符插入也会影响文本和细节标签的定位。

我用这个解出来了

override func layoutSubviews() {
    super.layoutSubviews()

    separatorInset = UIEdgeInsets(top: 0, left: layoutMargins.left, bottom: 0, right: width - layoutMargins.left)
}

对于iOS7或更高版本，更简洁的方法是使用INFINITY而不是硬编码的值。当屏幕旋转时，您不必担心更新单元格。

if (indexPath.row == <row number>) {
    cell.separatorInset = UIEdgeInsetsMake(0, INFINITY, 0, 0);
}