TestItemHelperActivity.java

package mcxtzhang.recyclerviewdemo.itemtouchhelper;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.helper.ItemTouchHelper;
import android.widget.Toast;

import com.mcxtzhang.commonadapter.rv.CommonAdapter;
import com.mcxtzhang.commonadapter.rv.ViewHolder;

import java.util.Collections;
import java.util.List;

import mcxtzhang.recyclerviewdemo.R;
import mcxtzhang.recyclerviewdemo.nestrv.TestBean;

import static mcxtzhang.recyclerviewdemo.nestrv.TestBean.fakerDatas;

public class TestItemHelperActivity extends AppCompatActivity {
    RecyclerView mRv;
    List<TestBean> mDatas;
    CommonAdapter mAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mRv = (RecyclerView) findViewById(R.id.rv);
        mRv.setLayoutManager(new LinearLayoutManager(this));
        mRv.setAdapter(mAdapter = new CommonAdapter<TestBean>(this, mDatas = fakerDatas(), R.layout.item_test_drag) {
            @Override
            public void convert(ViewHolder holder, TestBean testBean) {
                holder.setText(R.id.tv, testBean.getName());
            }
        });


        //0则不执行拖动或者滑动
        ItemTouchHelper.Callback mCallback = new ItemTouchHelper.SimpleCallback(/*ItemTouchHelper.UP */0, ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT) {
            @Override
            public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
                int fromPosition = viewHolder.getAdapterPosition();//得到拖动ViewHolder的position
                int toPosition = target.getAdapterPosition();//得到目标ViewHolder的position
                if (fromPosition < toPosition) {
                    //分别把中间所有的item的位置重新交换
                    for (int i = fromPosition; i < toPosition; i++) {
                        Collections.swap(mDatas, i, i + 1);
                    }
                } else {
                    for (int i = fromPosition; i > toPosition; i--) {
                        Collections.swap(mDatas, i, i - 1);
                    }
                }
                mAdapter.notifyItemMoved(fromPosition, toPosition);
                return true;
            }

            @Override
            public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
                Toast.makeText(TestItemHelperActivity.this, "滑动了：" + direction, Toast.LENGTH_SHORT).show();
            }

        };
        ItemTouchHelper itemTouchHelper = new ItemTouchHelper(mCallback);
        itemTouchHelper.attachToRecyclerView(mRv);
    }
}