对于那些只想摆脱默认选择灰色背景的人，把这行代码放在你的cellForRowAtIndexPath func中:

yourCell.selectionStyle = .None

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];
        }
    } 

自定义单元格类。覆盖:

- (void)setSelected:(BOOL)selected animated:(BOOL)animated {
    [super setSelected:selected animated:animated];

    // Configure the view for the selected state

    if (selected) {
        [self setBackgroundColor: CELL_SELECTED_BG_COLOR];
        [self.contentView setBackgroundColor: CELL_SELECTED_BG_COLOR];
    }else{
        [self setBackgroundColor: [UIColor clearColor]];
        [self.contentView setBackgroundColor: [UIColor clearColor]];
    }
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [tableView reloadData];
    UITableViewCell *cell=(UITableViewCell*)[tableView cellForRowAtIndexPath:indexPath];
    [cell setBackgroundColor:[UIColor orangeColor]];
}

对于Swift 3.0:

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    let cell = super.tableView(tableView, cellForRowAt: indexPath)

    cell.contentView.backgroundColor = UIColor.red
}

如果你有一个分组表，每个部分只有一个单元格，只需在代码中添加额外的一行: bgColorView.layer.cornerRadius = 10;

UIView *bgColorView = [[UIView alloc] init];
[bgColorView setBackgroundColor:[UIColor redColor]];
bgColorView.layer.cornerRadius = 10;
[cell setSelectedBackgroundView:bgColorView];
[bgColorView release]; 

不要忘记导入QuartzCore。