FlexboxLayoutManager 踩坑

在做一个流式布局搜索历史UI，当我在给RecyclerView添加HeaderView的时候，报如下异常
ClassCastException: android.support.v7.widget.RecyclerView$LayoutParams cannot be cast to com.google.android.flexbox.FlexItem

就是说，我们添加的HeaderView，无法转换成FlexlItem，但是为了复用，踩坑吧！百度引擎是搜不到，只能起飞了，Google 一下就找到了解决方法，实现自己的 FlexboxLayoutManager

/**
 * Created by dzh on 02.23.023.
 */
public class MyFlexboxLayoutManager extends FlexboxLayoutManager{
    public MyFlexboxLayoutManager(Context context) {
        super(context);
    }

    public MyFlexboxLayoutManager(Context context, int flexDirection) {
        super(context, flexDirection);
    }

    public MyFlexboxLayoutManager(Context context, int flexDirection, int flexWrap) {
        super(context, flexDirection, flexWrap);
    }


    /**
     * 将LayoutParams转换成新的FlexboxLayoutManager.LayoutParams
     */
    @Override
    public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) {
        if (lp instanceof RecyclerView.LayoutParams) {
            return new FlexboxLayoutManager.LayoutParams((RecyclerView.LayoutParams) lp);
        } else if (lp instanceof ViewGroup.MarginLayoutParams) {
            return new FlexboxLayoutManager.LayoutParams((ViewGroup.MarginLayoutParams) lp);
        } else {
            return new FlexboxLayoutManager.LayoutParams(lp);
        }
    }
}