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>