iOS8 之后 tableview separatorInset cell分割线左对齐，ios7的方法失效了

-(void)viewDidLayoutSubviews {
 
    if ([self.mytableview respondsToSelector:@selector(setSeparatorInset:)]) {
        [self.mytableview setSeparatorInset:UIEdgeInsetsZero];
 
    }
    if ([self.mytableview respondsToSelector:@selector(setLayoutMargins:)])  {
        [self.mytableview setLayoutMargins:UIEdgeInsetsZero];
    }
 
}
 
-(void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPat{
    if ([cell respondsToSelector:@selector(setLayoutMargins:)]) {
        [cell setLayoutMargins:UIEdgeInsetsZero];
    }
    if ([cell respondsToSelector:@selector(setSeparatorInset:)]){
        [cell setSeparatorInset:UIEdgeInsetsZero];
    }
}