单击展开式列表视图中的子项时如何在另一个活动中打开列表视图

Question

I am creating an app for my school. It is supposed to contain lecture notes of each course offered in the institution. Now there are three different schools in the institution with each having at least four departments so my main activity has an expandable listview which shows the different departments when any school is clicked.

I want to be able to open a new activity which is populated with courses offered in that department in a listview when a particular child item (department) is clicked. Also when the new list activity of courses is opened the user should be able to view the lecture notes of that course in another activity, without creating activities and layouts for each department and course.

This is my main activity

public class MainActivity extends Activity {

    ExpandableListAdapter listAdapter;
    ExpandableListView expListView;
    List<String> listDataHeader;
    HashMap<String, List<String>> listDataChild;

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

        // get the listview
        expListView = (ExpandableListView) findViewById(R.id.lvExp);

        // preparing list data
        prepareListData();

        listAdapter = new ExpandableListAdapter(this, listDataHeader, listDataChild);

        // setting list adapter
        expListView.setAdapter(listAdapter);

        // Listview Group click listener
        expListView.setOnGroupClickListener(new OnGroupClickListener() {

            @Override
            public boolean onGroupClick(ExpandableListView parent, View v,
                    int groupPosition, long id) {
                // Toast.makeText(getApplicationContext(),
                // "Group Clicked " + listDataHeader.get(groupPosition),
                // Toast.LENGTH_SHORT).show();
                return false;
            }
        });

        // Listview Group expanded listener
        expListView.setOnGroupExpandListener(new OnGroupExpandListener() {

            @Override
            public void onGroupExpand(int groupPosition) {
                Toast.makeText(getApplicationContext(),
                        listDataHeader.get(groupPosition) + " Expanded",
                        Toast.LENGTH_SHORT).show();
            }
        });

        // Listview Group collasped listener
        expListView.setOnGroupCollapseListener(new OnGroupCollapseListener() {

            @Override
            public void onGroupCollapse(int groupPosition) {
                Toast.makeText(getApplicationContext(),
                        listDataHeader.get(groupPosition) + " Collapsed",
                        Toast.LENGTH_SHORT).show();

            }
        });

        // Listview on child click listener
        expListView.setOnChildClickListener(new OnChildClickListener() {

            @Override
            public boolean onChildClick(ExpandableListView parent, View v,
                    int groupPosition, int childPosition, long id) {
                // TODO Auto-generated method stub
                Toast.makeText(
                        getApplicationContext(),
                        listDataHeader.get(groupPosition)
                                + " : "
                                + listDataChild.get(
                                        listDataHeader.get(groupPosition)).get(
                                        childPosition), Toast.LENGTH_SHORT)
                        .show();
                return false;
            }
        });
    }

    /*
     * Preparing the list data
     */
    private void prepareListData() {
        listDataHeader = new ArrayList<String>();
        listDataChild = new HashMap<String, List<String>>();

        // Adding child data
        listDataHeader.add("School Of Applied Science");
        listDataHeader.add("School Of Business And Management Studies");
        listDataHeader.add("School Of Engineering");

        // Adding child data
        List<String> schoolOfAppliedScience = new ArrayList<String>();
        schoolOfAppliedScience.add("Computer Science");
        schoolOfAppliedScience.add("Statistics");
        schoolOfAppliedScience.add("Science Laboratory Technology");
        schoolOfAppliedScience.add("Hotel Catering And Institutional Management");
        schoolOfAppliedScience.add("Fashion Design And Textiles");

        List<String> BAMS = new ArrayList<String>();
        BAMS.add("Secretaryship And Management Studies");
        BAMS.add("Marketing");
        BAMS.add("Accounting");
        BAMS.add("Purchasing And Supply");

        List<String> schOfEngineering = new ArrayList<String>();
        schOfEngineering.add("Electrical Engineering");
        schOfEngineering.add("Automotive Engineering");
        schOfEngineering.add("Building Technology");
        schOfEngineering.add("Civil Engineering");

        listDataChild.put(listDataHeader.get(0), schoolOfAppliedScience); // Header, Child data
        listDataChild.put(listDataHeader.get(1), BAMS);
        listDataChild.put(listDataHeader.get(2), schOfEngineering);
    }
}

Here is my adapter class

public class ExpandableListAdapter extends BaseExpandableListAdapter {

    private Context _context;
    private List<String> _listDataHeader; // header titles
    // child data in format of header title, child title
    private HashMap<String, List<String>> _listDataChild;

    public ExpandableListAdapter(Context context, List<String> listDataHeader,
            HashMap<String, List<String>> listChildData) {
        this._context = context;
        this._listDataHeader = listDataHeader;
        this._listDataChild = listChildData;
    }

    @Override
    public Object getChild(int groupPosition, int childPosititon) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .get(childPosititon);
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    @Override
    public View getChildView(int groupPosition, final int childPosition,
            boolean isLastChild, View convertView, ViewGroup parent) {

        final String childText = (String) getChild(groupPosition, childPosition);

        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.list_item, null);
        }

        TextView txtListChild = (TextView) convertView
                .findViewById(R.id.lblListItem);

        txtListChild.setText(childText);
        return convertView;
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .size();
    }

    @Override
    public Object getGroup(int groupPosition) {
        return this._listDataHeader.get(groupPosition);
    }

    @Override
    public int getGroupCount() {
        return this._listDataHeader.size();
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
            View convertView, ViewGroup parent) {
        String headerTitle = (String) getGroup(groupPosition);
        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.list_group, null);
        }

        TextView lblListHeader = (TextView) convertView
                .findViewById(R.id.lblListHeader);
        lblListHeader.setTypeface(null, Typeface.BOLD);
        lblListHeader.setText(headerTitle);

        return convertView;
    }

    @Override
    public boolean hasStableIds() {
        return false;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }

}

Answer 1

    // Listview on child click listener
    expListView.setOnChildClickListener(new OnChildClickListener() {

        @Override
        public boolean onChildClick(ExpandableListView parent, View v,
                int groupPosition, int childPosition, long id) {
            // TODO Auto-generated method stub

if (groupPosition == 0) {

      if (childPosition == 0)
         {
            Intent c = new Intent(getApplicationContext(),ComputerScience.class);
            startActivity(c);
         }
      if (childPosition == 1) {
            Intent c = new Intent(getApplicationContext(), Statistics.class);
            startActivity(c);
        }
        if (childPosition == 2) {
            Intent c = new Intent(getApplicationContext(), ScienceLaboratoryTechnology.class);
            startActivity(c);
        }
        if (childPosition == 3) {
            Intent c = new Intent(getApplicationContext(),HotelCateringAndInstitutionalManagement.class);
            startActivity(c);
        }
        if (childPosition == 4) {
            Intent c = new Intent(getApplicationContext(),FashionDesignAndTextiles.class);
            startActivity(c);
        }
    }

   if (groupPosition == 1) {

      if (childPosition == 0)
         {
            Intent c = new Intent(getApplicationContext(),SecretaryshipAndManagementStudies.class);
            startActivity(c);
         }
      if (childPosition == 1) {
            Intent c = new Intent(getApplicationContext(), Marketing.class);
            startActivity(c);
        }
        if (childPosition == 2) {
            Intent c = new Intent(getApplicationContext(), PurchasingAndSupply.class);
            startActivity(c);
        }
        if (childPosition == 3) {
            Intent c = new Intent(getApplicationContext(),HotelCateringAndInstitutionalManagement.class);
            startActivity(c);
        }

    }
    if (groupPosition == 2) {
        if (childPosition == 0) {
            Intent c = new Intent(getApplicationContext(), AutomotiveEngineering.class);
            startActivity(c);
        }
        if (childPosition == 1) {
            Intent c = new Intent(getApplicationContext(), BuildingTechnology.class);
            startActivity(c);
        }
        if (childPosition == 2) {
            Intent c = new Intent(getApplicationContext(), CivilEngineering.class);
            startActivity(c);
        }

    }
    return false;
}
 });

Answer 2

try android.widget.AdapterView.OnItemClickListener.

   expListView.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long arg3) {

            StartIntent();
        }

    });

Answer 3

You just need to modify the getChildView method, add OnClickListener like this:

     @Override
         public View getChildView(final int groupPosition, final int childPosition,
         boolean isLastChild, View convertView, ViewGroup parent) {

         final String childText = (String) getChild(groupPosition, childPosition);

         if (convertView == null) {
         LayoutInflater infalInflater = (LayoutInflater) this._context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
         convertView = infalInflater.inflate(R.layout.list_item, null);
         }

         TextView txtListChild = (TextView) convertView.findViewById(R.id.lblListItem);     
         txtListChild.setText(childText);
         //-----------------------------------------------------------------------------------
         txtListChild.setOnClickListener(new View.OnClickListener() {    
             @Override
             public void onClick(View view) {

//put your groupPosition and childPosition to the intent and start the activity

                 startActivity(YOUR INTENT);

             }    
         }//-----------------------------------------------------------------------------------


         return convertView;
         }

Or, you can setOnClickListener for childs layout :

convertView.setOnClickListener(...)

Answer 4

Have a look at here in developer docs

---

   mExpandableList.setOnChildClickListener(new OnChildClickListener() {

       @Override
       public boolean onChildClick(ExpandableListView parent, View v,int groupPosition, int childPosition, long id) {

          /*Additional info: You can use the view variable(v) here to get the params from the view you are clicking just in case you want to pass any data of that view to new activity(use casting to casting point to a particular view type). then pass that data as extra along with intent */

          Intent intent=new Intent(CurrentClass.this,NewActivity.class)
          startActivity(intent);     

          return true;
        }
    });

Note: Don't forget to declare NewActivity calss in manifest

Answer 5

public class MyExpandableAdapter extends BaseExpandableListAdapter
{
    private Activity activity;
    private ArrayList<Object> childtems;
    private LayoutInflater inflater;
    private ArrayList<String> parentItems, child;
    private Context context;


    // constructor
    public MyExpandableAdapter(ArrayList<String> parents, ArrayList<Object> childern)
    {
        this.parentItems = parents;
        this.childtems = childern;


    }

    public void setInflater(LayoutInflater inflater, Activity activity)
    {
        this.inflater = inflater;
        this.activity = activity;
    }

    // method getChildView is called automatically for each child view.
    //  Implement this method as per your requirement
    @Override
    public View getChildView(final int groupPosition, final int childPosition, boolean isLastChild, View convertView, ViewGroup parent)
    {

        child = (ArrayList<String>) childtems.get(groupPosition);

        TextView textView = null;
        ImageView img = null;

        if (convertView == null) {
            convertView = inflater.inflate(R.layout.child_view, null);
        }

        // get the textView reference and set the value
        textView = (TextView) convertView.findViewById(R.id.textViewChild);
        textView.setText(child.get(childPosition));
        img = (ImageView) convertView.findViewById(R.id.childImage);


            if (childPosition == 0 && groupPosition==0) {
                img.setImageResource(R.drawable.slika1);
            }
            if (childPosition == 1 && groupPosition==0) {
                img.setImageResource(R.drawable.slika2);
            }
            if (childPosition == 2 && groupPosition==0) {
                img.setImageResource(R.drawable.slika1);
            }
            if (childPosition == 3 && groupPosition==0) {
                img.setImageResource(R.drawable.slika2);
            }
            if (childPosition == 4 && groupPosition==0) {
                img.setImageResource(R.drawable.slika1);
            }
            if (childPosition == 5 && groupPosition==0) {
                img.setImageResource(R.drawable.slika2);
            }
            if (childPosition == 6 && groupPosition==0) {
                img.setImageResource(R.drawable.slika1);
            }
            if (childPosition == 7 && groupPosition==0) {
                img.setImageResource(R.drawable.slika2);
            }
            if (childPosition == 8 && groupPosition==0) {
                img.setImageResource(R.drawable.slika1);
            }
            if (childPosition == 0 && groupPosition==1) {
                img.setImageResource(R.drawable.slika2);
            }
            if (childPosition == 1 && groupPosition==1) {
                img.setImageResource(R.drawable.slika1);
            }
            if (childPosition == 2 && groupPosition==1) {
                img.setImageResource(R.drawable.slika2);
            }
            if (childPosition == 3 && groupPosition==1) {
                img.setImageResource(R.drawable.slika1);
            }
            if (childPosition == 0 && groupPosition==2) {
                img.setImageResource(R.drawable.slika2);
            }
            if (childPosition == 1 && groupPosition==2) {
                img.setImageResource(R.drawable.slika1);
            }
            if (childPosition == 2 && groupPosition==2 ) {
                img.setImageResource(R.drawable.slika2);
            }
            if (childPosition == 3 && groupPosition==2) {
                img.setImageResource(R.drawable.slika1);
            }
            if (childPosition == 0 && groupPosition==3) {
                img.setImageResource(R.drawable.slika2);
            }
            if (childPosition == 1 && groupPosition==3) {
                img.setImageResource(R.drawable.slika1);
            }
            if (childPosition == 2 && groupPosition==3) {
                img.setImageResource(R.drawable.slika2);
            }
            if (childPosition == 3 && groupPosition==3) {
                img.setImageResource(R.drawable.slika1);
            }




        // set the ClickListener to handle the click event on child item
       //convertView.setOnClickListener(new View.OnClickListener() {

        textView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(activity, child.get(childPosition),
                        Toast.LENGTH_SHORT).show();
            }
        });
        return convertView;
    }

    // method getGroupView is called automatically for each parent item
    // Implement this method as per your requirement
    @Override
    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent)
    {

        if (convertView == null) {
            convertView = inflater.inflate(R.layout.parent_view, null);
        }

        ((CheckedTextView) convertView).setText(parentItems.get(groupPosition));
        ((CheckedTextView) convertView).setChecked(isExpanded);

        return convertView;
    }


    @Override
    public Object getChild(int groupPosition, int childPosition)
    {
        return null;
    }

    @Override
    public long getChildId(int groupPosition, int childPosition)
    {
        return 0;
    }

    @Override
    public int getChildrenCount(int groupPosition)
    {
        return ((ArrayList<String>) childtems.get(groupPosition)).size();
    }

    @Override
    public Object getGroup(int groupPosition)
    {
        return null;
    }

    @Override
    public int getGroupCount()
    {
        return parentItems.size();
    }

    @Override
    public void onGroupCollapsed(int groupPosition)
    {
        super.onGroupCollapsed(groupPosition);
    }

    @Override
    public void onGroupExpanded(int groupPosition)
    {
        super.onGroupExpanded(groupPosition);
    }

    @Override
    public long getGroupId(int groupPosition)
    {
        return 0;
    }

    @Override
    public boolean hasStableIds()
    {
        return false;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition)
    {
        return false;
    }
}