int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder)

ItemTouchHelper.UP //滑动拖拽向上方向
ItemTouchHelper.DOWN//向下
ItemTouchHelper.LEFT//向左
ItemTouchHelper.RIGHT//向右
ItemTouchHelper.START//依赖布局方向的水平开始方向
ItemTouchHelper.END//依赖布局方向的水平结束方向

boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target)

void onSwiped(RecyclerView.ViewHolder viewHolder, int direction)

 /**
  * Item是否支持长按拖动
  *
  * @return
  *   true 支持长按操作
  *   false 不支持长按操作
  */
boolean isLongPressDragEnabled()

 /**
  * Item是否支持滑动
  *
  * @return
  *   true 支持滑动操作
  *   false 不支持滑动操作
  */
boolean isItemViewSwipeEnabled()

 /**
  * 移动过程中绘制Item
  *
  * @param c
  * @param recyclerView
  * @param viewHolder
  * @param dX
  *   X轴移动的距离
  * @param dY
  *   Y轴移动的距离
  * @param actionState
  *   当前Item的状态
  * @param isCurrentlyActive
  *   如果当前被用户操作为true，反之为false
  */
onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive)

  adapter=new CustomAdapter(getActivity(),strings);
  recycleview.setAdapter(adapter);
  ItemTouchHelper.Callback callback=new RecycleItemTouchHelper(adapter);
  ItemTouchHelper itemTouchHelper=new ItemTouchHelper(callback);
  itemTouchHelper.attachToRecyclerView(recycleview);

package com.example.xh.adapter;

import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.helper.ItemTouchHelper;
import android.util.Log;
import android.view.View;

import com.example.xh.R;
import com.example.xh.utils.MyApplication;

/**
 * Created by xiehui on 2017/2/23.
 */
public class RecycleItemTouchHelper extends ItemTouchHelper.Callback{
 private static final String TAG ="RecycleItemTouchHelper" ;
 private final ItemTouchHelperCallback helperCallback;

 public RecycleItemTouchHelper(ItemTouchHelperCallback helperCallback) {
  this.helperCallback = helperCallback;
 }

 /**
  * 设置滑动类型标记
  *
  * @param recyclerView
  * @param viewHolder
  * @return
  *   返回一个整数类型的标识，用于判断Item那种移动行为是允许的
  */
 @Override
 public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
  Log.e(TAG, "getMovementFlags: " );
  //START 右向左 END左向右 LEFT 向左 RIGHT向右 UP向上
  //如果某个值传0，表示不触发该操作，次数设置支持上下拖拽，支持向右滑动
  return makeMovementFlags(ItemTouchHelper.UP|ItemTouchHelper.DOWN,ItemTouchHelper.END );
 }
 /**
  * Item是否支持长按拖动
  *
  * @return
  *   true 支持长按操作
  *   false 不支持长按操作
  */
 @Override
 public boolean isLongPressDragEnabled() {
  return super.isLongPressDragEnabled();
 }
 /**
  * Item是否支持滑动
  *
  * @return
  *   true 支持滑动操作
  *   false 不支持滑动操作
  */
 @Override
 public boolean isItemViewSwipeEnabled() {
  return super.isItemViewSwipeEnabled();
 }
 /**
  * 拖拽切换Item的回调
  *
  * @param recyclerView
  * @param viewHolder
  * @param target
  * @return
  *   如果Item切换了位置，返回true；反之，返回false
  */
 @Override
 public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
  Log.e(TAG, "onMove: " );
  helperCallback.onMove(viewHolder.getAdapterPosition(),target.getAdapterPosition());
  return true;
 }
 /**
  * 滑动Item
  *
  * @param viewHolder
  * @param direction
  *   Item滑动的方向
  */
 @Override
 public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
  Log.e(TAG, "onSwiped: ");
  helperCallback.onItemDelete(viewHolder.getAdapterPosition());
 }
 /**
  * Item被选中时候回调
  *
  * @param viewHolder
  * @param actionState
  *   当前Item的状态
  *   ItemTouchHelper.ACTION_STATE_IDLE 闲置状态
  *   ItemTouchHelper.ACTION_STATE_SWIPE 滑动中状态
  *   ItemTouchHelper#ACTION_STATE_DRAG 拖拽中状态
  */
 @Override
 public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {
  super.onSelectedChanged(viewHolder, actionState);
 }
 public interface ItemTouchHelperCallback{
  void onItemDelete(int positon);
  void onMove(int fromPosition,int toPosition);
 }
}

 @Override
 public void onItemDelete(int positon) {
  list.remove(positon);
  notifyItemRemoved(positon);
 }

 @Override
 public void onMove(int fromPosition, int toPosition) {
  Collections.swap(list,fromPosition,toPosition);//交换数据
  notifyItemMoved(fromPosition,toPosition);
 }

onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive)

 /**
  * 移动过程中绘制Item
  *
  * @param c
  * @param recyclerView
  * @param viewHolder
  * @param dX
  *   X轴移动的距离
  * @param dY
  *   Y轴移动的距离
  * @param actionState
  *   当前Item的状态
  * @param isCurrentlyActive
  *   如果当前被用户操作为true，反之为false
  */
 @Override
 public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
  //滑动时自己实现背景及图片
  if (actionState==ItemTouchHelper.ACTION_STATE_SWIPE){

   //dX大于0时向右滑动，小于0向左滑动
   View itemView=viewHolder.itemView;//获取滑动的view
   Resources resources= MyApplication.getAppContext().getResources();
   Bitmap bitmap= BitmapFactory.decodeResource(resources, R.drawable.delete);//获取删除指示的背景图片
   int padding =10;//图片绘制的padding
   int maxDrawWidth=2*padding+bitmap.getWidth();//最大的绘制宽度
   Paint paint=new Paint();
   paint.setColor(resources.getColor(R.color.btninvalid));
   int x=Math.round(Math.abs(dX));
   int drawWidth=Math.min(x,maxDrawWidth);//实际的绘制宽度，取实时滑动距离x和最大绘制距离maxDrawWidth最小值
   int itemTop=itemView.getBottom()-itemView.getHeight();//绘制的top位置
   //向右滑动
   if(dX>0){
    //根据滑动实时绘制一个背景
    c.drawRect(itemView.getLeft(),itemTop,drawWidth,itemView.getBottom(),paint);
    //在背景上面绘制图片
    if (x>padding){//滑动距离大于padding时开始绘制图片
     //指定图片绘制的位置
     Rect rect=new Rect();//画图的位置
     rect.left=itemView.getLeft()+padding;
     rect.top=itemTop+(itemView.getBottom()-itemTop-bitmap.getHeight())/2;//图片居中
     int maxRight=rect.left+bitmap.getWidth();
     rect.right=Math.min(x,maxRight);
     rect.bottom=rect.top+bitmap.getHeight();
     //指定图片的绘制区域
     Rect rect1=null;
     if (x<maxRight){
      rect1=new Rect();//不能再外面初始化，否则dx大于画图区域时，删除图片不显示
      rect1.left=0;
      rect1.top = 0;
      rect1.bottom=bitmap.getHeight();
      rect1.right=x-padding;
     }
     c.drawBitmap(bitmap,rect1,rect,paint);
    }
    //绘制时需调用平移动画，否则滑动看不到反馈
    itemView.setTranslationX(dX);
   }else {
    //如果在getMovementFlags指定了向左滑动（ItemTouchHelper。START）时则绘制工作可参考向右的滑动绘制，也可直接使用下面语句交友系统自己处理
    super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
   }
  }else {
   //拖动时有系统自己完成
   super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
  }
 }

    float alpha = 1.0f - Math.abs(dX) / (float) itemView.getWidth();
    itemView.setAlpha(alpha);