Android DynamicGrid实现拖曳交换位置功能

 @Override
  public void onBackPressed() {
 
    //此处将取消拖曳编辑模式，取消方式为按返回键。
    if (gridView.isEditMode()) {
      gridView.stopEditMode();
    } else {
      super.onBackPressed();
    }
  }

package zhangphil.app;
 
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.TextView;
import android.widget.Toast;
 
import org.askerov.dynamicgrid.BaseDynamicGridAdapter;
import org.askerov.dynamicgrid.DynamicGridView;
 
import java.util.ArrayList;
import java.util.List;
 
public class MainActivity extends Activity {
 
  private DynamicGridView gridView;
 
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
 
    gridView = (DynamicGridView) findViewById(R.id.dynamicgrid);
 
    ArrayList lists = new ArrayList();
    for (int i = 0; i < 100; i++) {
      lists.add("项目-" + i);
    }
 
    //最好以完全方式构造，否则可能无法正常工作
    MyAdapter adapter = new MyAdapter(this, lists, 3);
    gridView.setAdapter(adapter);
 
    gridView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
      @Override
      public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
 
        //长按触发拖曳交换位置操作。
        gridView.startEditMode(position);
 
        return true;
      }
    });
 
    gridView.setOnDragListener(new DynamicGridView.OnDragListener() {
      @Override
      public void onDragStarted(int position) {
        //Toast.makeText(getApplication(), "drag started at position " + position,Toast.LENGTH_SHORT).show();
      }
 
      @Override
      public void onDragPositionsChanged(int oldPosition, int newPosition) {
        Toast.makeText(getApplication(), String.format("from %d to %d", oldPosition, newPosition), Toast.LENGTH_SHORT).show();
      }
    });
  }
 
  @Override
  public void onBackPressed() {
 
    //此处将取消拖曳编辑模式，取消方式为按返回键。
    if (gridView.isEditMode()) {
      gridView.stopEditMode();
    } else {
      super.onBackPressed();
    }
  }
 
  private class MyAdapter extends BaseDynamicGridAdapter {
 
    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
      View v = LayoutInflater.from(getContext()).inflate(android.R.layout.simple_list_item_1, null);
      TextView text = (TextView) v.findViewById(android.R.id.text1);
      text.setText("项目-" + i);
      v.setPadding(10, 10, 10, 10);
      return v;
    }
 
    public MyAdapter(Context context, List<?> items, int columnCount) {
      super(context, items, columnCount);
    }
  }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="match_parent"
  android:layout_height="match_parent">
 
  <org.askerov.dynamicgrid.DynamicGridView
    android:id="@+id/dynamicgrid"
    android:layout_height="wrap_content"
    android:layout_width="match_parent"
    android:numColumns="3"/>
</LinearLayout>