RecycleView 在实战中所需要的方法 ---- 持续更新

1 RecycleView 通过/位置 id找到所对应的ViewHolder
recyclerView.findViewHolderForAdapterPosition(i);
recyclerView.findViewHolderForItemId()

2 判断RecycleView  是否滑动到最底端

LinearLayoutManager  layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
        //添加滚动监听器
        recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
                super.onScrollStateChanged(recyclerView, newState);
                // 当不滚动时
                if (newState == AbsListView.OnScrollListener.SCROLL_STATE_IDLE) {
                    // 判断是否滚动到底部
                    //得到可见视图项最底层id
                    int lostPos = layoutManager.findLastVisibleItemPosition();
                    if (lostPos == layoutManager.getItemCount() - 1) {
                        //Toast.makeText(ShowActivity.this, "最后：" + lostPos, Toast.LENGTH_SHORT).show();
                       
                    }
                }
            }
        });

3 动态设置RecycleView的大小   适用于在同一个活动中使用2个recycleview的情况

 for(int i=0; i<adapter1.getItemCount(); i++) {
            View listItem=recyclerView1.findViewHolderForAdapterPosition(i).itemView;
            listItem.measure(0, 0);
            totalHeight += listItem.getMeasuredHeight();

        }   

        ViewGroup.LayoutParams params = recyclerView1.getLayoutParams();
         params.height = totalHeight + (recyclerView1.getDividerHeight() * (listAdapter.getCount() - 1));
        //recyclerView1.getDividerHeight()获取子项间分隔符占用的高度
        //params.height最后得到整个recyclerView1完整显示需要的高度
            recyclerView1.setLayoutParams(params);

4 设置recycleview的视图项之间的分割线
先自定义定义一个分割线类

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.View;


/**
 * This class is from the v7 samples of the Android SDK. It's not by me!
 * <p/>
 * See the license above for details.
 */
public class DividerItemDecoration extends RecyclerView.ItemDecoration {

    private static final int[] ATTRS = new int[]{
            android.R.attr.listDivider
    };

    public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;

    public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;

    private Drawable mDivider;

    private int mOrientation;

    public DividerItemDecoration(Context context, int orientation) {
        final TypedArray a = context.obtainStyledAttributes(ATTRS);
        mDivider = a.getDrawable(0);
        a.recycle();
        setOrientation(orientation);
    }

    public void setOrientation(int orientation) {
        if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {
            throw new IllegalArgumentException("invalid orientation");
        }
        mOrientation = orientation;
    }

    @Override
    public void onDraw(Canvas c, RecyclerView parent) {
        Log.v("recyclerview - itemdecoration", "onDraw()");

        if (mOrientation == VERTICAL_LIST) {
            drawVertical(c, parent);
        } else {
            drawHorizontal(c, parent);
        }

    }


    public void drawVertical(Canvas c, RecyclerView parent) {
        final int left = parent.getPaddingLeft();
        final int right = parent.getWidth() - parent.getPaddingRight();

        final int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            android.support.v7.widget.RecyclerView v = new android.support.v7.widget.RecyclerView(parent.getContext());
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int top = child.getBottom() + params.bottomMargin;
            final int bottom = top + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    public void drawHorizontal(Canvas c, RecyclerView parent) {
        final int top = parent.getPaddingTop();
        final int bottom = parent.getHeight() - parent.getPaddingBottom();

        final int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int left = child.getRight() + params.rightMargin;
            final int right = left + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    @Override
    public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
        if (mOrientation == VERTICAL_LIST) {
            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
        } else {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        }
    }
}

使用

//添加分割线
          recyclerView.addItemDecoration(new DividerItemDecoration(this,
                    DividerItemDecoration.VERTICAL_LIST));

5 设置RecyclerView的滚动条
纵向显示

android:scrollbars="vertical"

横向显示

android:scrollbars="horizontal"

隐藏

android:scrollbars="none"