How to add a row in listveiw dynamically?

Question

I'm trying to create a row in listview dynamically by giving external data.

Each row in a listview has a string data and a switch. String data taken from an Edittext externally.
I have a EditText field. I will input the data through this.
I have a button . When it is pressed, the EditText content should be added to a new row of the listview along with a Switch
While adding the new row , care should be taken to retain the previously added row.

I got the code skeleton from web. This code is manipulated by me for my requirement.

The following code adds the row dynamically but it is clearing the previously added row. Kindly help . Thanks

This is my MainActivity.java

public class MainActivity extends Activity {
Switch sw1;

private ListView listView1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.fragment_main);
    }

    public void getdata(View v) {
        EditText et;
        String dev_name;
        et = (EditText)findViewById(R.id.editText1) ;
        dev_name = et.getText().toString() ;
        create(dev_name, null);

    }

    public void create (String str, Switch sw1) {

    Items   Items_data[] = new Items[]
            {
              new Items( str,sw1)
            };

      ItemsAdapter adapter = new ItemsAdapter (this,R.layout.items_row, Items_data);

       listView1 = (ListView)findViewById(R.id.listView1);
       listView1.setAdapter(adapter);
   }

}

This is my ItemsAdapter.java

public class ItemsAdapter   extends ArrayAdapter<Items>{

    Context context;
    int layoutResourceId;   
    Items data[] = null;

    public ItemsAdapter(Context context, int layoutResourceId, Items[] data) {
        super(context, layoutResourceId, data);
        this.layoutResourceId = layoutResourceId;
        this.context = context;
        this.data = data;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {


       View row = convertView;
        ItemsHolder holder = null;

        if(row == null)
        {
            LayoutInflater inflater = ((Activity)context).getLayoutInflater();
            row = inflater.inflate(layoutResourceId, parent, false);

            holder = new ItemsHolder();
            holder.txtTitle = (TextView)row.findViewById(R.id.listtext);
            holder.switch1= (Switch)row.findViewById(R.id.listswitch);


            row.setTag(holder);
        }
        else
        {
            holder = (ItemsHolder)row.getTag();
        }

        Items item = data[position];
        holder.txtTitle.setText(Items.tv);
        holder.switch1.setChecked(false);

        return row;
    }

    static class ItemsHolder
    {
       TextView txtTitle;
       Switch switch1;
    }

}

This is my Item class.

public class Items {

    public static String tv;
    public static Switch switc;

    public Items() {
        super();
    }

 public Items(String tv, Switch switc ) {
            super();
            this.tv = tv;
            this.switc = switc;
        }


}

score 0 · Answer 1 · edited May 23 '17 at 12:03

Change your adapter declaration. May be below code help you.

public class MainActivity extends Activity {
Switch sw1;

private ListView listView1;
 ItemsAdapter adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.fragment_main);
        adapter = new ItemsAdapter (this,R.layout.items_row, Items_data);
    }

    public void getdata(View v) {
        EditText et;
        String dev_name;
        et = (EditText)findViewById(R.id.editText1) ;
        dev_name = et.getText().toString() ;
        create(dev_name, null);

    }

    public void create (String str, Switch sw1) {

    Items   Items_data[] = new Items[]
            {
              new Items( str,sw1)
            };

       adapter = new ItemsAdapter (this,R.layout.items_row, Items_data);

       listView1 = (ListView)findViewById(R.id.listView1);
       listView1.setAdapter(adapter);
   }

}

Check this link : Dynamically add elements to a listView Android

MeetTitan · Accepted Answer · 2015-10-18T08:10:43.543

You are assigning an array with one Items object that you create with the arguments passed in create(). You should try something like this:

public class MainActivity extends Activity {
    private Items[] items = new Items[0]; //We're making this a field, so we can create a new array containing our new item.
    ...
    public void create (String str, Switch sw1) {
        int i = items.length+1; //plus one because we are adding one element at a time. If you'd like to add more at once, change the 1 accordingly.
        Items[] tmp = new Items[i];
        System.arrayCopy(items, 0, tmp, 0, items.length);
        tmp[i] = new Items(str, sw1);
        items = tmp; //use items like you would use Items_data
        ...
    }
}

This adds the contents of items to tmp, and then adds our new item at the end. If you'd like your new item to be at the top of the stack, we can simply:

System.arrayCopy(items, 0, tmp, 1, items.length);
tmp[0] = new Items(str, sw1);

How to add a row in listveiw dynamically?

2 Answers2