［已解决］UITableViewCell中的contentView中的UILabel不显示

            let timestampLabelTextColor = UIColor.whiteColor()
            let timestampBackgroundColor = UIColor(white: 0.734, alpha: 1.0)

            let timestampLabel = UILabel(frame: CGRectMake(0, LabelPadding, UIScreen.mainScreen().bounds.size.width, TimeStampLabelHeight))
            //timestampLabel.text = ""
            timestampLabel.autoresizingMask = [UIViewAutoresizing.FlexibleWidth, UIViewAutoresizing.FlexibleHeight]
            timestampLabel.textColor = timestampLabelTextColor
            timestampLabel.backgroundColor = timestampBackgroundColor
            timestampLabel.textAlignment = NSTextAlignment.Center
            timestampLabel.font = UIFont.boldSystemFontOfSize(TimeStampLabelFont)
            //timestampLabel.center.x = 350
            timestampLabel.numberOfLines = 1
            timestampLabel.sizeToFit()
            self.timestampLabel = timestampLabel

            print("timestampLabel.frame=\(timestampLabel.frame)")

            self.contentView.addSubview(timestampLabel)
            self.contentView.bringSubviewToFront(timestampLabel)

    override func layoutSubviews() {
        super.layoutSubviews()

        print("after layoutSubviews, timestampLabel.frame=\(timestampLabel?.frame)")
    }

configureCell{
            self.timestampLabel?.text = "昨天 22:08"
            timestampLabel?.setNeedsLayout()
            print("self.timestampLabel?.text=\(self.timestampLabel?.text)")
}