仅将增量值传递给下一页的列表视图 [英] To pass only incremented value to listview on nextpage

问题描述

我可以在下一页的listview上发送数据.但是问题是数量为0的项目也被传递了.我想显示数量递增的项目，而不是listview中存在的所有项目.这是我的代码-

MainActivity.java

public class MainActivity extends Activity implements SearchView.OnQueryTextListener{

    Button show;
    ListView list_item;
    ArrayList<Items> itemsArrayList;
   SearchView searchview;


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

        list_item = (ListView) findViewById(R.id.listdetails);

        searchview=(SearchView)findViewById(R.id.searchView);
        show = (Button) findViewById(R.id.btnview);
        itemsArrayList=new ArrayList<>();
        itemsArrayList.add(new Items(1,"Book",20,0,0));
        itemsArrayList.add(new Items(2,"Pen",25,0,0));
        itemsArrayList.add(new Items(3,"Scale",10,0,0));
        itemsArrayList.add(new Items(4,"Eraser",5,0,0));

        show.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, Trial.class);
                intent.putExtra("data", itemsArrayList);
                startActivity(intent);
            }
        });


        Custom c = new Custom(this,itemsArrayList);
        list_item.setAdapter(c);
        list_item.setTextFilterEnabled(true);
        setupSearchView();

    }

   public void setupSearchView()
    {

        searchview.setOnQueryTextListener(this);

        searchview.setQueryHint("Search Here");
    }
    @Override
    public boolean onQueryTextSubmit(String s) {
        return false;
    }

    @Override
    public boolean onQueryTextChange(String s) {
        if (TextUtils.isEmpty(s)) {
            list_item.clearTextFilter();
        } else {
            list_item.setFilterText(s);
        }
        return true;
    }


}

Custom.java

public class Custom extends BaseAdapter implements Filterable{
    Activity a;
    ArrayList<Items> itemsArrayList;
    ArrayList<Items> filtered;




    public Custom(Activity a, ArrayList<Items> itemsArrayList) {
        this.a = a;
        this.itemsArrayList = itemsArrayList;
    }



    @Override
    public int getCount() {
        return itemsArrayList.size();
    }

    @Override
    public Object getItem(int i) {
        return itemsArrayList.get(i);
    }

    @Override
    public long getItemId(int i) {
        return i;
    }

    @Override
    public Filter getFilter() {
        return new Filter() {
            @Override
            protected FilterResults performFiltering(CharSequence charSequence) {
                FilterResults results=new FilterResults();
                ArrayList<Items> data=new ArrayList<Items>();
                if (filtered==null)
                    filtered=itemsArrayList;
                if (filtered != null && filtered.size() > 0) {
                    for (final Items g : filtered) {
                        if (g.getItemname().toLowerCase()
                                .contains(charSequence.toString()))
                            data.add(g);
                    }
                    results.values=data;
                }
                return results;
            }

            @Override
            protected void publishResults(CharSequence charSequence, FilterResults filterResults) {
                itemsArrayList=(ArrayList<Items>)filterResults.values;
                notifyDataSetChanged();
            }
        };
    }
    public void notifyDataSetChanged() {
        super.notifyDataSetChanged();
    }


    public class Holder{
        TextView sr,item,qty,price,pl,min,rate;


    }
    @Override
    public View getView(final int position, final View view, ViewGroup viewGroup) {
        final Holder holder=new Holder();
        LayoutInflater li=a.getLayoutInflater();
        final View view1=li.inflate(R.layout.customlist,viewGroup,false);
        holder.sr=(TextView)view1.findViewById(R.id.s_no);
        holder.item=(TextView)view1.findViewById(R.id.i_name);
        holder.qty=(TextView)view1.findViewById(R.id.qty);
        holder.price=(TextView)view1.findViewById(R.id.pr);
        holder.rate=(TextView)view1.findViewById(R.id.frate);
        holder.pl=(TextView) view1.findViewById(R.id.pl);
        holder.min=(TextView) view1.findViewById(R.id.min);
        final Items model = itemsArrayList.get(position);

        holder.sr.setText(String.valueOf(itemsArrayList.get(position).getSrno()));
        holder.item.setText(String.valueOf(itemsArrayList.get(position).getItemname()));
        holder.rate.setText(String .valueOf(itemsArrayList.get(position).getFixedrate()));
        holder.qty.setText(String.valueOf(itemsArrayList.get(position).getQuantity()));
        holder.price.setText(String .valueOf(itemsArrayList.get(position).getRate()));

        holder.pl.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {


                model.setQuantity(model.getQuantity() + 1);
                model.setRate(model.getQuantity()*model.getFixedrate());
                holder.qty.setText(String.valueOf(model.getQuantity()));
                holder.price.setText(String.valueOf(model.getRate()));
                notifyDataSetChanged();


            }
        });


        holder.min.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                if(model.getQuantity()>0) {
                    model.setQuantity(model.getQuantity() - 1);
                    model.setRate(model.getQuantity() * model.getFixedrate());
                    holder.qty.setText(String.valueOf(model.getQuantity()));
                    holder.price.setText(String.valueOf(model.getRate()));
                    notifyDataSetChanged();
                }
            }
        });
        return view1;
    }


}

Items.java

public class Items implements Serializable {
    int srno,fixedrate,quantity,rate;
    String itemname;

    public Items(int srno, String itemname, int fixedrate, int quantity, int rate) {
        this.srno = srno;
        this.itemname = itemname;
        this.fixedrate = fixedrate;
        this.quantity = quantity;
        this.rate = rate;
    }

    public int getSrno() {
        return srno;
    }

    public void setSrno(int srno) {
        this.srno = srno;
    }

    public String getItemname() {
        return itemname;
    }

    public void setItemname(String itemname) {
        this.itemname = itemname;
    }

    public int getFixedrate() {
        return fixedrate;
    }

    public void setFixedrate(int fixedrate) {
        this.fixedrate = fixedrate;
    }

    public int getQuantity() {
        return quantity;
    }

    public void setQuantity(int quantity) {
        this.quantity = quantity;
    }

    public int getRate() {
        return rate;
    }

    public void setRate(int rate) {
        this.rate = rate;
    }
}

Custom_Trial.java

public class Custom_Trial extends BaseAdapter {
    Activity a;
    private ArrayList<Items> data = new ArrayList<>();

    public Custom_Trial(Activity a, ArrayList<Items> data) {
        this.a = a;
        this.data = data;
    }

    @Override
    public int getCount() {

        return data.size();
    }

    @Override
    public Object getItem(int position) {
        return data.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    public class Holder {
        TextView sr, it, qty, amt;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        Holder holder = new Holder();
        LayoutInflater li = a.getLayoutInflater();
        View view = li.inflate(R.layout.customtrial, parent, false);
        holder.sr = (TextView) view.findViewById(R.id.head1);
        holder.it = (TextView) view.findViewById(R.id.head2);
        holder.qty = (TextView) view.findViewById(R.id.head3);
        holder.amt = (TextView) view.findViewById(R.id.head4);



        Items m = data.get(position);



            holder.sr.setText(String.valueOf(m.getSrno()));
            holder.it.setText(m.getItemname());
            holder.qty.setText(String.valueOf(m.getQuantity()));
            holder.amt.setText(String.valueOf(m.getRate()));




        return view;
    }

}

Trial.java

public class Trial extends Activity{
    ListView listnew;
    private ArrayList<Items> data = new ArrayList<>();



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

        listnew = (ListView) findViewById(R.id.newlist);

        data.addAll((ArrayList<Items>) getIntent().getSerializableExtra("data"));


        Custom_Trial ct = new Custom_Trial(this,data);
        listnew.setAdapter(ct);

    }



}

解决方案

这是因为您传递了原始列表.您正在更新适配器内的值，并且不传递来自适配器的更新列表，而是传递原始列表.在适配器内写入方法以返回更新的列表.

内部Custom.java适配器:

public ArrayList<Items> getItems(){
    ArrayList<Items> quantityArrayList;
    Items item;
    for (int i = 0; i < itemsArrayList.size(); i++){
        item =  itemsArrayList.get(i);
        if (item.getQuantity() > 0)
        quantityArrayList.add(item);
    }

    return quantityArrayList;
}

在MainActivity的onCreate()内部应如下所示.单击显示按钮后，您将从数量> 0的自定义适配器获取项目.

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

    list_item = (ListView) findViewById(R.id.listdetails);

    searchview=(SearchView)findViewById(R.id.searchView);
    show = (Button) findViewById(R.id.btnview);
    itemsArrayList=new ArrayList<>();
    itemsArrayList.add(new Items(1,"Book",20,0,0));
    itemsArrayList.add(new Items(2,"Pen",25,0,0));
    itemsArrayList.add(new Items(3,"Scale",10,0,0));
    itemsArrayList.add(new Items(4,"Eraser",5,0,0));

    Custom c = new Custom(this,itemsArrayList);
    list_item.setAdapter(c);
    list_item.setTextFilterEnabled(true);
    setupSearchView();

    show.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            Intent intent = new Intent(MainActivity.this, Trial.class);
            List<Items> quantityList = c.getItems();
            intent.putExtra("data", quantityList);
            startActivity(intent);
        }
    });

}

I am able to send data on listview in nextpage.But problem is that items with quantity 0 is also passed.I want to show items whose quantity is incremented and not all items present in listview.Here is my code-

MainActivity.java

public class MainActivity extends Activity implements SearchView.OnQueryTextListener{

    Button show;
    ListView list_item;
    ArrayList<Items> itemsArrayList;
   SearchView searchview;


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

        list_item = (ListView) findViewById(R.id.listdetails);

        searchview=(SearchView)findViewById(R.id.searchView);
        show = (Button) findViewById(R.id.btnview);
        itemsArrayList=new ArrayList<>();
        itemsArrayList.add(new Items(1,"Book",20,0,0));
        itemsArrayList.add(new Items(2,"Pen",25,0,0));
        itemsArrayList.add(new Items(3,"Scale",10,0,0));
        itemsArrayList.add(new Items(4,"Eraser",5,0,0));

        show.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, Trial.class);
                intent.putExtra("data", itemsArrayList);
                startActivity(intent);
            }
        });


        Custom c = new Custom(this,itemsArrayList);
        list_item.setAdapter(c);
        list_item.setTextFilterEnabled(true);
        setupSearchView();

    }

   public void setupSearchView()
    {

        searchview.setOnQueryTextListener(this);

        searchview.setQueryHint("Search Here");
    }
    @Override
    public boolean onQueryTextSubmit(String s) {
        return false;
    }

    @Override
    public boolean onQueryTextChange(String s) {
        if (TextUtils.isEmpty(s)) {
            list_item.clearTextFilter();
        } else {
            list_item.setFilterText(s);
        }
        return true;
    }


}

Custom.java

public class Custom extends BaseAdapter implements Filterable{
    Activity a;
    ArrayList<Items> itemsArrayList;
    ArrayList<Items> filtered;




    public Custom(Activity a, ArrayList<Items> itemsArrayList) {
        this.a = a;
        this.itemsArrayList = itemsArrayList;
    }



    @Override
    public int getCount() {
        return itemsArrayList.size();
    }

    @Override
    public Object getItem(int i) {
        return itemsArrayList.get(i);
    }

    @Override
    public long getItemId(int i) {
        return i;
    }

    @Override
    public Filter getFilter() {
        return new Filter() {
            @Override
            protected FilterResults performFiltering(CharSequence charSequence) {
                FilterResults results=new FilterResults();
                ArrayList<Items> data=new ArrayList<Items>();
                if (filtered==null)
                    filtered=itemsArrayList;
                if (filtered != null && filtered.size() > 0) {
                    for (final Items g : filtered) {
                        if (g.getItemname().toLowerCase()
                                .contains(charSequence.toString()))
                            data.add(g);
                    }
                    results.values=data;
                }
                return results;
            }

            @Override
            protected void publishResults(CharSequence charSequence, FilterResults filterResults) {
                itemsArrayList=(ArrayList<Items>)filterResults.values;
                notifyDataSetChanged();
            }
        };
    }
    public void notifyDataSetChanged() {
        super.notifyDataSetChanged();
    }


    public class Holder{
        TextView sr,item,qty,price,pl,min,rate;


    }
    @Override
    public View getView(final int position, final View view, ViewGroup viewGroup) {
        final Holder holder=new Holder();
        LayoutInflater li=a.getLayoutInflater();
        final View view1=li.inflate(R.layout.customlist,viewGroup,false);
        holder.sr=(TextView)view1.findViewById(R.id.s_no);
        holder.item=(TextView)view1.findViewById(R.id.i_name);
        holder.qty=(TextView)view1.findViewById(R.id.qty);
        holder.price=(TextView)view1.findViewById(R.id.pr);
        holder.rate=(TextView)view1.findViewById(R.id.frate);
        holder.pl=(TextView) view1.findViewById(R.id.pl);
        holder.min=(TextView) view1.findViewById(R.id.min);
        final Items model = itemsArrayList.get(position);

        holder.sr.setText(String.valueOf(itemsArrayList.get(position).getSrno()));
        holder.item.setText(String.valueOf(itemsArrayList.get(position).getItemname()));
        holder.rate.setText(String .valueOf(itemsArrayList.get(position).getFixedrate()));
        holder.qty.setText(String.valueOf(itemsArrayList.get(position).getQuantity()));
        holder.price.setText(String .valueOf(itemsArrayList.get(position).getRate()));

        holder.pl.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {


                model.setQuantity(model.getQuantity() + 1);
                model.setRate(model.getQuantity()*model.getFixedrate());
                holder.qty.setText(String.valueOf(model.getQuantity()));
                holder.price.setText(String.valueOf(model.getRate()));
                notifyDataSetChanged();


            }
        });


        holder.min.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                if(model.getQuantity()>0) {
                    model.setQuantity(model.getQuantity() - 1);
                    model.setRate(model.getQuantity() * model.getFixedrate());
                    holder.qty.setText(String.valueOf(model.getQuantity()));
                    holder.price.setText(String.valueOf(model.getRate()));
                    notifyDataSetChanged();
                }
            }
        });
        return view1;
    }


}

Items.java

public class Items implements Serializable {
    int srno,fixedrate,quantity,rate;
    String itemname;

    public Items(int srno, String itemname, int fixedrate, int quantity, int rate) {
        this.srno = srno;
        this.itemname = itemname;
        this.fixedrate = fixedrate;
        this.quantity = quantity;
        this.rate = rate;
    }

    public int getSrno() {
        return srno;
    }

    public void setSrno(int srno) {
        this.srno = srno;
    }

    public String getItemname() {
        return itemname;
    }

    public void setItemname(String itemname) {
        this.itemname = itemname;
    }

    public int getFixedrate() {
        return fixedrate;
    }

    public void setFixedrate(int fixedrate) {
        this.fixedrate = fixedrate;
    }

    public int getQuantity() {
        return quantity;
    }

    public void setQuantity(int quantity) {
        this.quantity = quantity;
    }

    public int getRate() {
        return rate;
    }

    public void setRate(int rate) {
        this.rate = rate;
    }
}

Custom_Trial.java

public class Custom_Trial extends BaseAdapter {
    Activity a;
    private ArrayList<Items> data = new ArrayList<>();

    public Custom_Trial(Activity a, ArrayList<Items> data) {
        this.a = a;
        this.data = data;
    }

    @Override
    public int getCount() {

        return data.size();
    }

    @Override
    public Object getItem(int position) {
        return data.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    public class Holder {
        TextView sr, it, qty, amt;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        Holder holder = new Holder();
        LayoutInflater li = a.getLayoutInflater();
        View view = li.inflate(R.layout.customtrial, parent, false);
        holder.sr = (TextView) view.findViewById(R.id.head1);
        holder.it = (TextView) view.findViewById(R.id.head2);
        holder.qty = (TextView) view.findViewById(R.id.head3);
        holder.amt = (TextView) view.findViewById(R.id.head4);



        Items m = data.get(position);



            holder.sr.setText(String.valueOf(m.getSrno()));
            holder.it.setText(m.getItemname());
            holder.qty.setText(String.valueOf(m.getQuantity()));
            holder.amt.setText(String.valueOf(m.getRate()));




        return view;
    }

}

Trial.java

public class Trial extends Activity{
    ListView listnew;
    private ArrayList<Items> data = new ArrayList<>();



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

        listnew = (ListView) findViewById(R.id.newlist);

        data.addAll((ArrayList<Items>) getIntent().getSerializableExtra("data"));


        Custom_Trial ct = new Custom_Trial(this,data);
        listnew.setAdapter(ct);

    }



}

解决方案

It's because you passing original list. You're updating values inside adapter and passing not updated list fromadapter, but original. Write method inside adapter to return your updated list.

Inside Custom.java adapter:

public ArrayList<Items> getItems(){
    ArrayList<Items> quantityArrayList;
    Items item;
    for (int i = 0; i < itemsArrayList.size(); i++){
        item =  itemsArrayList.get(i);
        if (item.getQuantity() > 0)
        quantityArrayList.add(item);
    }

    return quantityArrayList;
}

And inside MainActivity onCreate() should look like this. After clicking show button you're going to get Items from Custom Adapter whose quantity >0.

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

    list_item = (ListView) findViewById(R.id.listdetails);

    searchview=(SearchView)findViewById(R.id.searchView);
    show = (Button) findViewById(R.id.btnview);
    itemsArrayList=new ArrayList<>();
    itemsArrayList.add(new Items(1,"Book",20,0,0));
    itemsArrayList.add(new Items(2,"Pen",25,0,0));
    itemsArrayList.add(new Items(3,"Scale",10,0,0));
    itemsArrayList.add(new Items(4,"Eraser",5,0,0));

    Custom c = new Custom(this,itemsArrayList);
    list_item.setAdapter(c);
    list_item.setTextFilterEnabled(true);
    setupSearchView();

    show.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            Intent intent = new Intent(MainActivity.this, Trial.class);
            List<Items> quantityList = c.getItems();
            intent.putExtra("data", quantityList);
            startActivity(intent);
        }
    });

}

这篇关于仅将增量值传递给下一页的列表视图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！