为所有单元格添加背景(使用Maciej的答案):

for (int section = 0; section < [self.tableView numberOfSections]; section++) {
        for (int row = 0; row < [self.tableView numberOfRowsInSection:section]; row++) {
            NSIndexPath* cellPath = [NSIndexPath indexPathForRow:row inSection:section];
            UITableViewCell* cell = [self.tableView cellForRowAtIndexPath:cellPath];

            //stuff to do with each cell
            UIView *bgColorView = [[UIView alloc] init];
            bgColorView.backgroundColor = [UIColor redColor];
            [cell setSelectedBackgroundView:bgColorView];
        }
    } 

覆盖UITableViewCell的setSelected也可以。

override func setSelected(selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)

    // Set background color
    let view = UIView()
    view.backgroundColor = UIColor.redColor()
    selectedBackgroundView = view
}

为所有单元格添加背景(使用Maciej的答案):

for (int section = 0; section < [self.tableView numberOfSections]; section++) {
        for (int row = 0; row < [self.tableView numberOfRowsInSection:section]; row++) {
            NSIndexPath* cellPath = [NSIndexPath indexPathForRow:row inSection:section];
            UITableViewCell* cell = [self.tableView cellForRowAtIndexPath:cellPath];

            //stuff to do with each cell
            UIView *bgColorView = [[UIView alloc] init];
            bgColorView.backgroundColor = [UIColor redColor];
            [cell setSelectedBackgroundView:bgColorView];
        }
    } 

I've got a slightly different approach than everyone else that reflects the selection on touch rather than after being selected. I have a subclassed UITableViewCell. All you have to do is set the background color in the touch events, which simulates selection on touch, and then set the background color in the setSelected function. Setting the background color in the selSelected function allows for deselecting the cell. Make sure to pass the touch event to the super, otherwise the cell won't actually act as if its selected.

override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
    self.backgroundColor = UIColor(white: 0.0, alpha: 0.1)
    super.touchesBegan(touches, withEvent: event)
}

override func touchesCancelled(touches: NSSet!, withEvent event: UIEvent!) {
    self.backgroundColor = UIColor.clearColor()
    super.touchesCancelled(touches, withEvent: event)
}

override func setSelected(selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)

    // Configure the view for the selected state
    self.backgroundColor = selected ? UIColor(white: 0.0, alpha: 0.1) : UIColor.clearColor()
}

我认为你在正确的轨道上，但根据selectedBackgroundView的类定义:

对于普通样式表(UITableViewStylePlain)中的单元格，默认为nil，对于section-group表(UITableViewStyleGrouped)中的单元格，默认为非nil。

因此，如果你使用的是普通样式的表，那么你需要alloc-init一个新的UIView，有你想要的背景颜色，然后分配给selectedBackgroundView。

或者，如果你想要的是灰色背景当单元格被选中时，你可以使用这个:

cell.selectionStyle = UITableViewCellSelectionStyleGray;

-(void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
    UIView *view = [[UIView alloc] init];
    [view setBackgroundColor:[UIColor redColor]];
    [cell setSelectedBackgroundView:view];
}

我们需要在这个方法中设置所选的背景视图。