Hi I have this expandable list, I’m getting an error when I’m trying to

Question

0

Asked: May 26, 20262026-05-26T11:04:17+00:00 2026-05-26T11:04:17+00:00

Hi I have this expandable list, I’m getting an error when I’m trying to

0

Hi I have this expandable list, I’m getting an error when I’m trying to connect it to a xml file using this code.

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.directions);
    // Set up our adapter
    mAdapter = new MyExpandableListAdapter();
    setListAdapter(mAdapter);
    registerForContextMenu(getExpandableListView());
}

Using this code I get a force close when I the button that redirects to the whole java file. (Look below for full code)
Log Cat says this:

10-25 17:37:39.512: ERROR/AndroidRuntime(547):
java.lang.RuntimeException: Unable to start activity
ComponentInfo{com.sammy.umass/com.sammy.umass.DirectionsScreenActivity}:
java.lang.RuntimeException: Your content must have a
ExpandableListView whose id attribute is ‘android.R.id.list’

I just need remove the title bar, add an background image and pretty it up basically.

Full Code:

package com.sammy.umass;

import android.app.ExpandableListActivity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.Gravity;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.ContextMenu.ContextMenuInfo;
import android.widget.AbsListView;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ExpandableListView.ExpandableListContextMenuInfo;


public class DirectionsScreenActivity extends ExpandableListActivity {
ExpandableListAdapter mAdapter;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.directions);
    // Set up our adapter
    mAdapter = new MyExpandableListAdapter();
    setListAdapter(mAdapter);
    registerForContextMenu(getExpandableListView());
}

@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
    //menu.setHeaderTitle("Sample menu");
    //menu.add(0, 0, 0, R.string.expandable_list_sample_action);
}

@Override
public boolean onContextItemSelected(MenuItem item) {
    ExpandableListContextMenuInfo info = (ExpandableListContextMenuInfo) item.getMenuInfo();

    String title = ((TextView) info.targetView).getText().toString();

    int type = ExpandableListView.getPackedPositionType(info.packedPosition);
    if (type == ExpandableListView.PACKED_POSITION_TYPE_CHILD) {
        int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition); 
        int childPos = ExpandableListView.getPackedPositionChild(info.packedPosition); 
        Toast.makeText(this, title + ": Child " + childPos + " clicked in group " + groupPos,
                Toast.LENGTH_SHORT).show();
        return true;
    } else if (type == ExpandableListView.PACKED_POSITION_TYPE_GROUP) {
        int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition); 
        Toast.makeText(this, title + ": Group " + groupPos + " clicked", Toast.LENGTH_SHORT).show();
        return true;
    }

    return false;
}

/**
 * A simple adapter which maintains an ArrayList of photo resource Ids. 
 * Each photo is displayed as an image. This adapter supports clearing the
 * list of photos and adding a new photo.
 *
 */
public class MyExpandableListAdapter extends BaseExpandableListAdapter {
    // Sample data set.  children[i] contains the children (String[]) for groups[i].
    private String[] groups = { "   Academic Buildings", "   Residential Buildings", "   Dining Commons", "   All Buildings A-Z" };
    private String[][] children = {
            //Academic Buildings
            { "Agricultural Engineering Bldg", "Army ROTC Bldg", "Arnold House", "(Studio) Arts Building" },
            //Residence Halls
            { "Baker Hall", "Brett Hall", "Brooks Hall", "Brown Hall","Butterfield Hall","Cance Hall","Cashin Hall","Chadboourne Hall",
                "Coolidge Hall","Crabtree Hall","Crampton Hall","Dickinson Hall","Dwight Hall","Emerson Hall","Field Hall",
                "Gorman Hall","Grayson Hall","Greenough Hall","Hamlin Hall","James Hall","John Adams Hall","John Quincy Adams Hall",
                "Johnson Hall","Kennedy Hall","Knowlton Hall","Leach Hall","Lewis Hall","Lincoln Apts","Mackimmie Hall","Mary Lyon Hall",
                "McNamara Hall","Melville Hall","Moore Hall","North Residence A","North Residence B","North Residence C","North Residence D",
                "North Village Apts","Patterson Hall","Pierpont Hall","Prince Hall","Thatcher Hall","Thoreau Hall","Van Meter Hall",
                "Washington Hall","Webster Hall","Wheeler Hall"},
            //Dining Commons
            { "Berkshire", "Franklin","Hampden","Hampshire","Worcester" },
            { "Agricultural Engineering Bldg", "Army ROTC Bldg", "Arnold House", "(Studio) Arts Building" }
    };

    public Object getChild(int groupPosition, int childPosition) {
        return children[groupPosition][childPosition];
    }

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

    public int getChildrenCount(int groupPosition) {
        return children[groupPosition].length;
    }

    public TextView getGenericView() {
        // Layout parameters for the ExpandableListView
        AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
                ViewGroup.LayoutParams.MATCH_PARENT, 64);

        TextView textView = new TextView(DirectionsScreenActivity.this);
        textView.setLayoutParams(lp);
        // Center the text vertically
        textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
        // Set the text starting position
        textView.setPadding(36, 0, 0, 0);
        return textView;
    }

    public View getChildView(final int groupPosition,final int childPosition, boolean isLastChild,
            View convertView, ViewGroup parent) {
        TextView textView = getGenericView();
        textView.setText(getChild(groupPosition, childPosition).toString());
        textView.setOnClickListener(new View.OnClickListener(){
          public void onClick(View view){
            Uri uriToOpen = getUriForView(groupPosition, childPosition);
            Intent i = new Intent(Intent.ACTION_VIEW, uriToOpen);
            startActivity(i);
          }

        private Uri getUriForView(int groupPosition, int childPosition) 
        {
            //Academic Builds
            //Residence Halls
            if(groupPosition == 1 && childPosition == 0)
                return Uri.parse("google.navigation:q=160+Clark+Hill+Road+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 1)
                return Uri.parse("google.navigation:q=151+Infirmary+Way+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 2)
                return Uri.parse("google.navigation:q=160+Infirmary+Way+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 3)
                return Uri.parse("google.navigation:q=92+Eastman+Lane+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 4)
                return Uri.parse("google.navigation:q=171+Infirmary+Way+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 5)
                return Uri.parse("google.navigation:q=191+Fearing+Street+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 6)
                return Uri.parse("google.navigation:q=112+Eastman+Lane+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 7)
                return Uri.parse("google.navigation:q=110+Orchard+Hill+Drive+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 8)
                return Uri.parse("google.navigation:q=630+Massachusetts+Avenue+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 9)
                return Uri.parse("google.navigation:q=17+Eastman+Lane+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 10)
                return Uri.parse("google.navigation:q=256+Sunset+Avenue+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 11)
                return Uri.parse("google.navigation:q=151+Orchard+Hill+Drive+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 12)
                return Uri.parse("google.navigation:q=41+Eastman+Lane+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 13)
                return Uri.parse("google.navigation:q=151+Southwest+Circle+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 14)
                return Uri.parse("google.navigation:q=171+Orchard+Hill+Drive+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 15)
                return Uri.parse("google.navigation:q=90+Butterfield+Terrace+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 16)
                return Uri.parse("google.navigation:q=161+Orchard+Hill+Drive+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 17)
                return Uri.parse("google.navigation:q=120+Orchard+Hill+Drive+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 18)
                return Uri.parse("google.navigation:q=739+North+Pleasant+Street+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 19)
                return Uri.parse("google.navigation:q=660+Massachusetts+Avenue+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 20)
                return Uri.parse("google.navigation:q=161+Fearing+Street+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 21)
                return Uri.parse("google.navigation:q=171+Fearing+Street+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 22)
                return Uri.parse("google.navigation:q=380+Thatcher+Road+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 23)
                return Uri.parse("google.navigation:q=42.38421349589919+-72.52963542938232"+"&mode=w");
            if(groupPosition == 1 && childPosition == 24)
                return Uri.parse("google.navigation:q=691+North+Pleasant+Street+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 25)
                return Uri.parse("google.navigation:q=21+Eastman+Lane+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 26)
                return Uri.parse("google.navigation:q=340+Thatcher+Road+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 27)
                return Uri.parse("google.navigation:q=341+Lincoln+Avenue+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 28)
                return Uri.parse("google.navigation:q=230+Sunset+Avenue+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 29)
                return Uri.parse("google.navigation:q=43+Eastman+Lane+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 30)
                return Uri.parse("google.navigation:q=102+Eastman+Lane+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 31)
                return Uri.parse("google.navigation:q=650+Massachusetts+Avenue+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 32)
                return Uri.parse("google.navigation:q=111+Southwest+Circle+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 33)
                return Uri.parse("google.navigation:q=56+Eastman+Lane+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 34)
                return Uri.parse("google.navigation:q=58+Eastman+Lane+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 35)
                return Uri.parse("google.navigation:q=54+Eastman+Lane+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 36)
                return Uri.parse("google.navigation:q=52+Eastman+Lane+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 37)
                return Uri.parse("google.navigation:q=990+North+Pleasant+Street+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 38)
                return Uri.parse("google.navigation:q=204+Sunset+Avenue+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 39)
                return Uri.parse("google.navigation:q=201+Fearing+Street+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 40)
                return Uri.parse("google.navigation:q=286+Sunset+Avenue+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 41)
                return Uri.parse("google.navigation:q=300+Thatcher+Road+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 42)
                return Uri.parse("google.navigation:q=640+Massachusetts+Avenue+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 43)
                return Uri.parse("google.navigation:q=180+Clark+Hil+Road+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 44)
                return Uri.parse("google.navigation:q=181+Fearing+Street+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 45)
                return Uri.parse("google.navigation:q=141+Orchard+Hill+Drive+Amherst+MA+01003"+"&mode=w");
            if(groupPosition == 1 && childPosition == 46)
                return Uri.parse("google.navigation:q=171+Infirmary+Way+Amherst+MA+01003"+"&mode=w");
            //Dining Commons
            //All Buildings
            return null;
        }
        });

        return textView;
    }

    public Object getGroup(int groupPosition) {
        return groups[groupPosition];
    }

    public int getGroupCount() {
        return groups.length;
    }

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

    public View getGroupView(int groupPosition, boolean isExpanded, View convertView,
            ViewGroup parent) {
        TextView textView = getGenericView();
        textView.setText(getGroup(groupPosition).toString());
        return textView;
    }

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

    public boolean hasStableIds() {
        return true;
    }



}
}

XML CODE

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
</LinearLayout>

Report

Leave an answer
Cancel reply

You must login to add an answer.

Need An Account,

1 Answer

Editorial Team · Answer 1 · 2026-05-26T11:04:18+00:00

When using an ExpandableListAdapter, the supplied XML layout needs to have an ExpandableListView element in it with the id attribute set to android.R.id.list. Your problem is in your directions.xml layout. Make sure in your directions.xml there is an ExpandableListView element and it has the id attribute set to andoird.R.id.list. You need to do this in your directoions.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
       <ExpandableListView 
        android:id="@android:id/list"
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content">
        </ExpandableListView>

</LinearLayout>

Sign Up

Sign In

Forgot Password

The Archive Base Latest Questions

Hi I have this expandable list, I’m getting an error when I’m trying to

Leave an answerCancel reply

1 Answer

Leave an answer
Cancel reply