Swift 点击按钮两张图片之间来回切换

    func tapTimeRank() {
        mTimeRankBtn.addTarget(self, action: #selector(tapTimeRankImage(sender:)), for: .touchUpInside)
    }
    
    @objc func tapTimeRankImage(sender:UIButton) {
        if sender.isSelected {
            mTimeRankImage.image = UIImage(named: "rank_up")
        }else{
            mTimeRankImage.image = UIImage(named: "rank_down")
        }
        sender.isSelected = !sender.isSelected
    }    func tapTimeRank() {
        mTimeRankBt