Question

I separated my app in 3 classes. the main class where the user can choose which feature to use. The map feature works fine but my directions features doesn’t when the user clicks on the button is causes a force close, I think it has something to do with the layout.

Main Class file

package com.sammy.umass;

import android.app.Activity;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.content.Intent;
import android.widget.Button;



public class UMassGuide extends Activity {
/** Called when the activity is first created. */



//buttons
private Button goHereButton;
private Button mapButton;
private Button spireButton;
private Button sparkButton;
private Button websiteButton;

@Override
public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    goHereButton  = (Button) findViewById(R.id.button1);
    goHereButton.setOnClickListener(new View.OnClickListener() 
    {
       public void onClick(View arg0) 
       {
       Intent i = new Intent(UMassGuide.this, DirectionsScreenActivity.class);
       startActivity(i);
       }
    });

    mapButton  = (Button) findViewById(R.id.button2);
    mapButton.setOnClickListener(new View.OnClickListener() 
    {
       public void onClick(View arg0) 
       {
       Intent i = new Intent(UMassGuide.this, UmassMap.class);
       startActivity(i);
       }
    });

    spireButton  = (Button) findViewById(R.id.button3);
    spireButton.setOnClickListener(new View.OnClickListener() 
    {
        public void onClick(View arg0) 
        {
            Uri uri = Uri.parse("https://spire.umass.edu/psp/heproda/EMPLOYEE/HRMS/?cmd=login&languageCd=ENG&"); 
            Intent intent = new Intent(Intent.ACTION_VIEW, uri); startActivity(intent);
        }
     });

    sparkButton  = (Button) findViewById(R.id.button4);
    sparkButton.setOnClickListener(new View.OnClickListener() 
    {
        public void onClick(View arg0) 
        {
            Uri uri = Uri.parse("https://spark.oit.umass.edu/webct/logonDisplay.dowebct"); 
            Intent intent = new Intent(Intent.ACTION_VIEW, uri); startActivity(intent);
        }
     });

    websiteButton  = (Button) findViewById(R.id.button5);
    websiteButton.setOnClickListener(new View.OnClickListener() 
    {
        public void onClick(View arg0) 
        {
            Uri uri = Uri.parse("http://www.umass.edu/"); 
            Intent intent = new Intent(Intent.ACTION_VIEW, uri); startActivity(intent);
        }
     });




}
}

Directions File (Force Close happens when this classes is being opened)

package com.sammy.umass;

import android.app.ExpandableListActivity;
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);

    // 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 = {
            { "Agricultural Engineering Bldg", "Army ROTC Bldg", "Arnold House", "(Studio) Arts Building" },
            { "Baker Hall", "Brett Hall", "Brooks Hall", "Brown Hall" },
            { "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(int groupPosition, int childPosition, boolean isLastChild,
            View convertView, ViewGroup parent) {
        TextView textView = getGenericView();
        textView.setText(getChild(groupPosition, childPosition).toString());
        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;
    }

}
}

Answer 1

Have you added the DirectionScreenActivity to your Manifest file? If not, that could cause a fatal crash.