domingo, 23 de diciembre de 2012

Encabezados Titulos ListView / Android ListView with Section Header

URL ORIGEN: http://androidtrainningcenter.blogspot.com/2012/03/android-listview-with-section-header.html


Android ListView with Section Header

ListView is most power full Widget  in android.I have mention it every time i post related to ListView.We have already learned how to create a ListView with  BaseAdapter. Now in above case if you have following problem ---
  • You want to make a song list with header to make user interface more interactive
  • There may be many more cases in which we want to give our ListView more fancy way to interact with user
For creating a List-Activtiy or ListView with section wise, we need following thing--
  • Header XML
  • Normal ListRow XML
  • Main Activity with ListView
  • Adapter class

Now  i am going to explain with code now step by step

Step 1) Create one New project

Step 2) Create XML name item1.xml inside res/layout folder.


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_height="wrap_content"
 android:layout_width="fill_parent">
 <TextView
  android:id="@+id/text"
  android:layout_height="50dp"
  android:gravity="center_vertical"
  android:text="text"
  android:visibility="visible"
  android:layout_width="fill_parent"
  android:textColor="#FF000000"
  android:background="#FFFFFFFF" />
</LinearLayout>

Step 3) Create XML name item2.xml inside res/layout folder


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_height="wrap_content"
 android:layout_width="fill_parent">
 <TextView
  android:id="@+id/textSeparator"
  android:layout_height="wrap_content"
  android:gravity="center"
  android:text="text"
  android:visibility="visible"
  android:layout_width="fill_parent"
  android:textColor="#FFFFFFFF"
  android:background="#000" />
</LinearLayout>

Step 4) Change your activity to List-activity.You can implement with a normal activity. For this you have to take main.xml with ListView. Paste this code inside your list-activity



package com.ahmad.list;

import android.app.ListActivity;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.TreeSet;

public class MultipleItemsList extends ListActivity implements OnTouchListener{

    private MyCustomAdapter mAdapter;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mAdapter = new MyCustomAdapter();
        for (int i = 1; i < 50; i++) {
            mAdapter.addItem("Sameer Blog " + i);
            if (i % 4 == 0) {
                mAdapter.addSeparatorItem("Ahmad " + i);
            }
        }
        setListAdapter(mAdapter);
    }
 //Adapter Class
 private class MyCustomAdapter extends BaseAdapter {

        private static final int TYPE_ITEM = 0;
        private static final int TYPE_SEPARATOR = 1;
        private static final int TYPE_MAX_COUNT = TYPE_SEPARATOR + 1;

        private ArrayList<String> mData = new ArrayList<String>();
        private LayoutInflater mInflater;

        private TreeSet<Integer> mSeparatorsSet = new TreeSet<Integer>();

        public MyCustomAdapter() {
            mInflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        }

        public void addItem(final String item) {
            mData.add(item);
            notifyDataSetChanged();
        }

        public void addSeparatorItem(final String item) {
            mData.add(item);
            // save separator position
            mSeparatorsSet.add(mData.size() - 1);
            notifyDataSetChanged();
        }

        @Override
        public int getItemViewType(int position) {
            return mSeparatorsSet.contains(position) ? TYPE_SEPARATOR : TYPE_ITEM;
        }

        @Override
        public int getViewTypeCount() {
            return TYPE_MAX_COUNT;
        }

        public int getCount() {
            return mData.size();
        }

        public String getItem(int position) {
            return mData.get(position);
        }

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

        public View getView(int position, View convertView, ViewGroup parent) {
            ViewHolder holder = null;
            int type = getItemViewType(position);
            System.out.println("getView " + position + " " + convertView + " type = " + type);
            if (convertView == null) {
                holder = new ViewHolder();
                switch (type) {
                    case TYPE_ITEM:
                        convertView = mInflater.inflate(R.layout.item1, null);
                        holder.textView = (TextView)convertView.findViewById(R.id.text);
                        break;
                    case TYPE_SEPARATOR:
                        convertView = mInflater.inflate(R.layout.item2, null);
                        holder.textView = (TextView)convertView.findViewById(R.id.textSeparator);
                        break;
                }
                convertView.setTag(holder);
            } else {
                holder = (ViewHolder)convertView.getTag();
            }
            holder.textView.setText(mData.get(position));
            return convertView;
        }

    }

    public static class ViewHolder {
        public TextView textView;
    }

 public boolean onTouch(View v, MotionEvent event) {
  // TODO Auto-generated method stub
  return false;
 }
}

Screen Shot of output of this Program ---


Feel free to comment for suggestion and issue







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