Question

我有一个列表视图，如下图所示。

现在我想一次从列表视图中选择 Only any two items ，并将带有Intent的listview项的值传递给下一个活动。我怎样才能实现它。？

如果两个项目都未选中，则设置验证吗？

AdapterClass

@Override
public void mouseExited(MouseEvent e) {
   if (!clicked) {
      if (insideArea(e)) {
         ...

主类

public class LoadAdapter extends BaseAdapter {
    private ArrayList<DataBase> mProductItems;
    private LayoutInflater mLayoutInflater;
    private Context mContext;
    DBHelper mydb;
    DataBase stringItem;
    public LoadAdapter(Context context, ArrayList<DataBase> arrayList){
        mContext = context;
        mProductItems = arrayList;
        mLayoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        Log.e("testtt", String.valueOf(mProductItems.size()));
        return mProductItems.size();

    }

    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return 0;
    }



    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        final ViewHolder holder;

        if (convertView == null) {
            holder = new ViewHolder();
            convertView = mLayoutInflater.inflate(R.layout.load_chart_item, parent, false);
            holder.txtv_name = (TextView) convertView.findViewById(R.id.text);
            holder.nameid = (TextView) convertView.findViewById(R.id.nameid);
            holder.btn_delete = (Button) convertView.findViewById(R.id.btn_delete);
            holder.btn_edit = (Button)convertView.findViewById(R.id.btn_edit);
            holder.location = (TextView)convertView.findViewById(R.id.loc);
            holder.img= (ImageView)convertView.findViewById(R.id.img);
            holder.btn_delete.setTag(position);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder)convertView.getTag();
        }

        mydb = new DBHelper(mContext);

         stringItem = mProductItems.get(position);

        if (stringItem != null) {
            if (holder.txtv_name != null) {

                holder.txtv_name.setText(stringItem.getName());
                holder.nameid.setText(stringItem.getId());
                holder.location.setText(stringItem.getLocation());
                Log.e("saved Location  values",stringItem.getLocation());
            }
        }


 if(selected.get(position))
    {
        //for selected row
        holder.img.setBackgroundResource(R.drawble.myimg)
    }
    else
    {
        // for not selected row

    }


        holder.btn_delete.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

                DataBase test = mProductItems.get(position);
                String id =  test.getId();

                mydb.deleteContact(Integer.valueOf(id));
                mProductItems.remove(mProductItems.get(position));
                LoadAdapter.this.notifyDataSetChanged();


                if (mProductItems.size() == 0){
                    mProductItems.clear();
                    LoadAdapter.this.notifyDataSetChanged();
                }



            }
        });




        Log.e("DataBase", String.valueOf(mydb.getAllCotacts()));

        holder.btn_edit.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent intent=new Intent(mContext,UpdateData.class).setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

                SharedPreferences preff = PreferenceManager.getDefaultSharedPreferences(mContext);
                SharedPreferences.Editor edi = preff.edit();
                edi.putString("key",String.valueOf(position+1));
                edi.apply();

                mContext.startActivity(intent);
            }
        });

              return convertView;
    }

    public void refresh(ArrayList<DataBase> items)
    {
        this.mProductItems = items;
        notifyDataSetChanged();
    }


    private static class ViewHolder {
        ImageView img;
        TextView txtv_name,nameid,location;
        Button btn_delete,btn_edit;
    }
}

logcat的

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.View;
import android.widget.Button;

import java.util.ArrayList;


public class LoadChart extends AppCompatActivity {
    public final static String EXTRA_MESSAGE = "MESSAGE";
    private SwipeListView listView;
    DBHelper mydb;
    Button det;
    LoadAdapter loadAdapter;
    ArrayList<DataBase> array_list;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.load_chart);


         mydb = new DBHelper(this);
         array_list = mydb.getAllCotacts();
        Log.e("logging", String.valueOf(array_list));
     //   ArrayAdapter<String> arrayAdapter=new ArrayAdapter<String>(this,R.layout.load_chart_item,R.id.text, array_list);

          det = (Button)findViewById(R.id.reli);

        listView = (SwipeListView) findViewById(R.id.listview);
        listView.setAdapter(new LoadAdapter(getApplicationContext(),array_list));


        det.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            String str = "";
            str =  relationAdapter.getSelected();
            Toast.makeText(RelationShipChartList.this, str, Toast.LENGTH_SHORT).show();

        }
    });


        listView.setSwipeListViewListener(new BaseSwipeListViewListener() {
            int openItem = -1;
            int lastOpenedItem = -1;
            int lastClosedItem = -1;

            @Override
            public void onOpened(int position, boolean toRight) {
                lastOpenedItem = position;

                int index = position - listView.getFirstVisiblePosition();
                View view = listView.getChildAt(index);
                Button delete = (Button) view.findViewById(R.id.btn_delete);
                Button edit = (Button) view.findViewById(R.id.btn_edit);

               if (!toRight) {

                    delete.setVisibility(View.VISIBLE);
                    edit.setVisibility(View.VISIBLE);

                }


                if (openItem > -1 && lastOpenedItem != lastClosedItem) {
                    listView.closeAnimate(openItem);


                }
                openItem = position;
            }


            @Override
            public void onStartClose(int position, boolean right) {
                Log.d("swipe", String.format("onStartClose %d", position));
                lastClosedItem = position;

            }

            @Override
            public void onClosed(int position, boolean fromRight) {

                int index = position - listView.getFirstVisiblePosition();
                View view = listView.getChildAt(index);
                Button delete = (Button) view.findViewById(R.id.btn_delete);
                Button edit = (Button) view.findViewById(R.id.btn_edit);



                if (!fromRight) {

                    delete.setVisibility(View.INVISIBLE);
                    edit.setVisibility(View.INVISIBLE);

                }

            }

            @Override
            public void onListChanged() {

            }

            @Override
            public void onMove(int position, float x) {

            }

            @Override
            public void onStartOpen(int position, int action, boolean right) {
            }

            @Override
            public void onClickFrontView(int position) {

                int id_To_Search = position;

                DataBase test = array_list.get(position);
                String id =  test.getId();
                String name = test.getName();
                String loc = test.getLocation();
                String dt = test.getDate();
                String time = test.getTime();

                Bundle dataBundle = new Bundle();
                dataBundle.putString("name",name);
                dataBundle.putString("date",dt);
                dataBundle.putString("time",time);
                dataBundle.putString("location",loc);
                dataBundle.putInt("id", Integer.parseInt(id));
                Intent intent = new Intent(getApplicationContext(),LoadedChart.class);
                intent.putExtras(dataBundle);
                startActivity(intent);

            }

            @Override
            public void onClickBackView(int position) {

                Log.e("swipe", String.format("onClickBackView %d", position));
            }

            @Override
            public void onDismiss(int[] reverseSortedPositions) {

            }

        });
    }

    public int convertDpToPixel(float dp) {
        DisplayMetrics metrics = getResources().getDisplayMetrics();
        float px = dp * (metrics.densityDpi / 160f);
        return (int) px;
    }
    @Override
    public void onResume()
    {
        super.onResume();
        Set_Referash_Data();

    }


    public void Set_Referash_Data() {
        array_list.clear();
        mydb = new DBHelper(this);

        ArrayList<DataBase> con = mydb.getAllCotacts();

        for (int i = 0; i < con.size(); i++) {

            String  tidno = con.get(i).getId();
            String name = con.get(i).getName();
            String cons = con.get(i).getCon();
            String loc = con.get(i).getLocation();
            DataBase cnt = new DataBase();
            cnt.setId(tidno);
            cnt.setName(name);
            cnt.setCon(cons);
            cnt.setLocation(loc);
            array_list.add(cnt);

            Log.e(String.valueOf(array_list),"RefreshData");

        }
        mydb.close();


        array_list = mydb.getAllCotacts(); //reload the items from database
        LoadAdapter ld = new LoadAdapter(getApplicationContext(),array_list);
        listView.setAdapter(ld);
        ld.refresh(array_list);
        ld.notifyDataSetChanged();
        Log.e(String.valueOf(array_list),"RefreshData Final");
    }

}

Answer 1

我会将动作模式与MultiChoiceModeListener一起使用。

http://developer.android.com/reference/android/widget/AbsListView.MultiChoiceModeListener.html

有一个回调onItemCheckedStateChanged(ActionMode mode, int position, boolean checked)。

您可以轻松获取已检查列表项ListView.getCheckedItemPositions的值。所以你可以阻止选择，如果你已经选择了两个，或者甚至一次性地传递了所选择的值（或ids）而没有任何努力。

Answer 2

您可以简单地在项目选择上设置一个计数器。

以变量为例说明

i_count

在将项目标记为已选择/取消选择之前检查此变量：

struct inode

这将使您一次只能选择两个项目。

像这样修改你的适配器：

int count = 0;

编辑2：从适配器中获取选定的项目定义如下方法适配器并使用适配器对象调用它，如：if(item.isSelected()) { // you need to make is disable if(count>0) { count--; // // mark item as deselected } } else { // make it selected if(count<2) { count++; // mark item as selected } }

public class LoadAdapter extends BaseAdapter {
private ArrayList<DataBase> mProductItems;
private LayoutInflater mLayoutInflater;
private Context mContext;
DBHelper mydb;
DataBase stringItem;
ArrayList<Boolean> selected = new ArrayList<>();
private int count=0;

public LoadAdapter(Context context, ArrayList<DataBase> arrayList){
    mContext = context;
    mProductItems = arrayList;
    mLayoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    for (int i = 0; i < arrayList.size(); i++) {

        selected.add(false);

    }
}

@Override
public int getCount() {
    // TODO Auto-generated method stub
    Log.e("testtt", String.valueOf(mProductItems.size()));
    return mProductItems.size();

}

@Override
public Object getItem(int position) {
    // TODO Auto-generated method stub
    return null;
}

@Override
public long getItemId(int position) {
    // TODO Auto-generated method stub
    return 0;
}



@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    final ViewHolder holder;

    if (convertView == null) {
        holder = new ViewHolder();
        convertView = mLayoutInflater.inflate(R.layout.load_chart_item, parent, false);
        holder.txtv_name = (TextView) convertView.findViewById(R.id.text);
        holder.nameid = (TextView) convertView.findViewById(R.id.nameid);
        holder.btn_delete = (Button) convertView.findViewById(R.id.btn_delete);
        holder.btn_edit = (Button)convertView.findViewById(R.id.btn_edit);
        holder.location = (TextView)convertView.findViewById(R.id.loc);
        holder.btn_delete.setTag(position);
        convertView.setTag(holder);
    } else {
        holder = (ViewHolder)convertView.getTag();
    }

    mydb = new DBHelper(mContext);

    stringItem = mProductItems.get(position);

    if (stringItem != null) {
        if (holder.txtv_name != null) {

            holder.txtv_name.setText(stringItem.getName());
            holder.nameid.setText(stringItem.getId());
            holder.location.setText(stringItem.getLocation());
            Log.e("saved Location  values",stringItem.getLocation());
        }
    }

    if(selected.get(position))
    {
        //for selected row
        holder.txtv_name.setTextColor(color.red);
    }
    else
    {
        // for not selected row
        holder.txtv_name.setTextColor(color.black);
    }

    holder.txtv_name.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            if(holder.txtv_name.getCurrentTextColor()== R.color.black)
            {
                //is not selected
                if(count<2)
                {
                    count++;
                    selected.set(position,true);

                    // mark item as selected
                }
            }
            else
            {
                //is selected
                if(count>0)
                {
                    count--;
                    selected.set(position,false);

                    // // mark item as deselected
                }
            }
            notifyDataSetChanged();
        }
    });


    holder.btn_delete.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

            DataBase test = mProductItems.get(position);
            String id =  test.getId();

            mydb.deleteContact(Integer.valueOf(id));
            mProductItems.remove(mProductItems.get(position));
            LoadAdapter.this.notifyDataSetChanged();


            if (mProductItems.size() == 0){
                mProductItems.clear();
                LoadAdapter.this.notifyDataSetChanged();
            }



        }
    });




    Log.e("DataBase", String.valueOf(mydb.getAllCotacts()));

    holder.btn_edit.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            Intent intent=new Intent(mContext,UpdateData.class).setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

            SharedPreferences preff = PreferenceManager.getDefaultSharedPreferences(mContext);
            SharedPreferences.Editor edi = preff.edit();
            edi.putString("key",String.valueOf(position+1));
            edi.apply();

            mContext.startActivity(intent);
        }
    });

    return convertView;
}

public void refresh(ArrayList<DataBase> items)
{
    this.mProductItems = items;
    notifyDataSetChanged();
}


private static class ViewHolder {
    TextView txtv_name,nameid,location;
    Button btn_delete,btn_edit;
}}

回答问题2 ：如果要使用ImageView而不是文本颜色更改。执行与上述相同的操作，但将 TextView + Color 替换为 ImageView + Image 。

编辑3：

您已从 Null 对象调用adp.getSelected()方法。像这样修改你的代码：

public String getSelected() {
    String selectedString = "";
    int num=0;
    for (int i = 0; i < selected.size(); i++) {
        if (selected.get(i)) {
            num++;
            if (num == 1) {
                selectedString = mProductItems.get(i).getName();
            } else {
                selectedString += "," + mProductItems.get(i).getName();
            }
        }
    }
    return selectedString;
}

如何同时选择两个列表项？具体来说，只有两个项目不超过这个

2 个答案: