您没有初始化imageView。请在getView中添加以下行以及其他textView。

ImageView icDownarrow = (ImageView) view.findViewById(R.id.icUparrow);

全局删除以下变量（第29行）

ImageView icDownarrow,icUparrow;

最终输出将为

TextView timetxt = (TextView) view.findViewById(R.id.timetxt);
TextView codetxt = (TextView) view.findViewById(R.id.codetxt);
TextView moduletxt = (TextView) view.findViewById(R.id.moduletxt);
TextView stafftxt = (TextView) view.findViewById(R.id.stafftxt);
ImageView icDownarrow = (ImageView) view.findViewById(R.id.icUparrow);

icDownarrow.setOnClickListener(new View.OnClickListener() {
    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    @Override
    public void onClick(View view) {
        if (expandedLay.getVisibility() == View.GONE) {
            TransitionManager.beginDelayedTransition(cardView, new AutoTransition());
            expandedLay.setVisibility(View.VISIBLE);
            icDownarrow.setVisibility(View.GONE);
        } else {
            TransitionManager.beginDelayedTransition(cardView, new AutoTransition());
            expandedLay.setVisibility(View.GONE);
        }
    }
});