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Swift 3, Swift 4和Swift 5中，你可以像这样写一个UITableViewCell扩展:

extension UITableViewCell {
  func separator(hide: Bool) {
    separatorInset.left = hide ? bounds.size.width : 0
  }
}

然后你可以这样使用它(当cell是你的cell实例时):

cell.separator(hide: false) // Shows separator 
cell.separator(hide: true) // Hides separator

将表格视图单元格的宽度赋为左插入值比赋给它一些随机数更好。因为在某些屏幕尺寸中，也许不是现在，但将来你的分隔符仍然是可见的因为这个随机数可能不够。此外，在iPad横屏模式下，你不能保证你的分隔符总是不可见。

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;
}

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);
}

所有答案的代码将使单元格填充为零，而不是默认值。我在iOS 11 iPad Pro 12中看到了这个问题。”

但我有一个解决方案(“肮脏的hack”)，那就是使一个空的部分，将使分隔线隐藏。

下面是我使用的代码:

typedef enum PXSettingsTableSections {
    PXSettingSectionInvite = 0,
    PXSettingSectionAccount,
    PXSettingSectionPrivacy,
    PXSettingSectionCreation,
    PXSettingSectionTest,
    PXSettingSectionAboutHide,  // invisble section just to hide separator Line
    PXSettingSectionFooterHide, // invisble section just to hide separator Line
    PXSettingSectionNumItems,
} PXSettingsTableSectionsType;


- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    // Return the number of sections.
    return PXSettingSectionNumItems;
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    switch (section) {
        case PXSettingSectionInvite: return 1;
        case PXSettingSectionAccount:return (isSocialLogin) ? 1 : 2;
        case PXSettingSectionPrivacy: return 1;
        case PXSettingSectionCreation: return 2;
        case PXSettingSectionTest: return 3;
        case PXSettingSectionAboutHide: return 3;
        default: return 0;
    }
}


- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
    switch(section)
    {
        case PXSettingSectionInvite: return nil;
        case PXSettingSectionAccount: return @"Account";
        case PXSettingSectionPrivacy: return @"Privacy";
        case PXSettingSectionCreation: return @"Someting";
        case PXSettingSectionTest: return @"Test";
        case PXSettingSectionAboutHide: return @" ";
        case PXSettingSectionFooterHide: return @" ";
    }
    return nil;
}


- (void)tableView:(UITableView *)tableView willDisplayHeaderView:(UIView *)view forSection:(NSInteger)section {

    UITableViewHeaderFooterView *header = (UITableViewHeaderFooterView *)view;
    if (section == PXSettingSectionFooterHide || section == PXSettingSectionAboutHide) {
        // [UIColor clearColor] will not work 
        [header.contentView setBackgroundColor:[UIColor whiteColor]];
    }
}


- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
{
    // You can control here the size of one specific section
    if(section == PXSettingSectionAboutHide){
        return 0.0000001; //make it real small
    }
    return 45.0;
}


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

    switch(indexPath.section)
    {
        case PXSettingSectionInvite:
            return self.inviteCell;
        case PXSettingSectionAccount:
            if (isSocialLogin) {
                return self.myWalletCell;
            }
            switch(indexPath.row)
            {
                case 0: return self.changePasswordCell;
                case 1: return self.myWalletCell;
            }
        case PXSettingSectionPrivacy:
            switch(indexPath.row)
        {
            case 0: return self.privateAccountCell;
        }
        case PXSettingSectionCreation:
            switch(indexPath.row)
        {
            case 0: return self.videoResolutionCell;
            case 1: return self.selfieMirrorCell;
        }
        case PXSettingSectionTest:
            switch(indexPath.row)
        {
            case 0: return self.termsOfUseImageCell;
            case 1: return self.attributionCell;
            case 2: return self.aboutCell;
        }
        case PXSettingSectionAboutHide:{
            switch(indexPath.row)
            {
                case 0: return self.clearCacheCell;
                case 1: return self.feedbackCell;
                case 2: return self.logoutCell;
            }
        }
    }

    return self.emptyCell;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    [self.tableView setSeparatorStyle:UITableViewCellSeparatorStyleNone];
}