CODEWITHSUNDEEP
androidandroid-fragmentsfragment
RunningWalks
RunningWalks

Reputation: 119

Fragment - Unable to instantiate activity

I have an activity class connected directly to the main fragment class. Once a button on that class is clicked, it is meant to take me to another class where details are input. The first class works but as soon as the button is clicked the following error is produced:

03-20 16:11:17.055: E/AndroidRuntime(828): FATAL EXCEPTION: main
03-20 16:11:17.055: E/AndroidRuntime(828): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{app.norman.tennis/app.norman.tennis.fours.AddActivity}: java.lang.ClassCastException: app.norman.tennis.fours.AddActivity cannot be cast to android.app.Activity
03-20 16:11:17.055: E/AndroidRuntime(828):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1879)
03-20 16:11:17.055: E/AndroidRuntime(828):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1980)
03-20 16:11:17.055: E/AndroidRuntime(828):  at android.app.ActivityThread.access$600(ActivityThread.java:122)
03-20 16:11:17.055: E/AndroidRuntime(828):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1146)
03-20 16:11:17.055: E/AndroidRuntime(828):  at android.os.Handler.dispatchMessage(Handler.java:99)
03-20 16:11:17.055: E/AndroidRuntime(828):  at android.os.Looper.loop(Looper.java:137)
03-20 16:11:17.055: E/AndroidRuntime(828):  at android.app.ActivityThread.main(ActivityThread.java:4340)
03-20 16:11:17.055: E/AndroidRuntime(828):  at java.lang.reflect.Method.invokeNative(Native Method)
03-20 16:11:17.055: E/AndroidRuntime(828):  at java.lang.reflect.Method.invoke(Method.java:511)
03-20 16:11:17.055: E/AndroidRuntime(828):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
03-20 16:11:17.055: E/AndroidRuntime(828):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
03-20 16:11:17.055: E/AndroidRuntime(828):  at dalvik.system.NativeStart.main(Native Method)
03-20 16:11:17.055: E/AndroidRuntime(828): Caused by: java.lang.ClassCastException: app.norman.tennis.fours.AddActivity cannot be cast to android.app.Activity
03-20 16:11:17.055: E/AndroidRuntime(828):  at android.app.Instrumentation.newActivity(Instrumentation.java:1023)
03-20 16:11:17.055: E/AndroidRuntime(828):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1870)
03-20 16:11:17.055: E/AndroidRuntime(828):  ... 11 more

Below is the first class that displays the button (FoursFragment):

 public class FoursFragment extends Fragment {

private DbHelper mHelper;
private SQLiteDatabase dataBase;

private ArrayList<String> userId = new ArrayList<String>();
private ArrayList<String> user_fName = new ArrayList<String>();
private ArrayList<String> user_lName = new ArrayList<String>();

private ListView userList;
private AlertDialog.Builder build;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.display_activity, container, false);

    userList = (ListView) view.findViewById(R.id.List);

    mHelper = new DbHelper(getActivity());

    //add new record
    view.findViewById(R.id.btnAdd).setOnClickListener(new OnClickListener() {

        public void onClick(View v) {

            Intent i = new Intent(getActivity(),
                    AddActivity.class);
            i.putExtra("update", false);
            startActivity(i);

        }
    });

    //click to update data
    userList.setOnItemClickListener(new OnItemClickListener() {

        public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                long arg3) {

            Intent i = new Intent(getActivity(),
                    AddActivity.class);
            i.putExtra("Fname", user_fName.get(arg2));
            i.putExtra("Lname", user_lName.get(arg2));
            i.putExtra("ID", userId.get(arg2));
            i.putExtra("update", true);
            startActivity(i);

        }
    });

    //long click to delete data
    userList.setOnItemLongClickListener(new OnItemLongClickListener() {

        public boolean onItemLongClick(AdapterView<?> arg0, View arg1,
                final int arg2, long arg3) {

            build = new AlertDialog.Builder(getActivity());
            build.setTitle("Delete " + user_fName.get(arg2) + " "
                    + user_lName.get(arg2));
            build.setMessage("Do you want to delete ?");
            build.setPositiveButton("Yes",
                    new DialogInterface.OnClickListener() {

                        public void onClick(DialogInterface dialog,
                                int which) {

                            Toast.makeText(
                                    getActivity(),
                                    user_fName.get(arg2) + " "
                                            + user_lName.get(arg2)
                                            + " is deleted.", 3000).show();

                            dataBase.delete(
                                    DbHelper.TABLE_NAME,
                                    DbHelper.KEY_ID + "="
                                            + userId.get(arg2), null);
                            displayData();
                            dialog.cancel();
                        }
                    });

            build.setNegativeButton("No",
                    new DialogInterface.OnClickListener() {

                        public void onClick(DialogInterface dialog,
                                int which) {
                            dialog.cancel();
                        }
                    });
            AlertDialog alert = build.create();
            alert.show();

            return true;
        }
    });
    return view;
}

@Override
public void onResume() {
    displayData();
    super.onResume();
}

/**
 * displays data from SQLite
 */
private void displayData() {
    dataBase = mHelper.getWritableDatabase();
    Cursor mCursor = dataBase.rawQuery("SELECT * FROM "
            + DbHelper.TABLE_NAME, null);

    userId.clear();
    user_fName.clear();
    user_lName.clear();
    if (mCursor.moveToFirst()) {
        do {
            userId.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_ID)));
            user_fName.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_FNAME)));
            user_lName.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_LNAME)));

        } while (mCursor.moveToNext());
    }
    DisplayAdapter disadpt = new DisplayAdapter(getActivity(),userId, user_fName, user_lName);
    userList.setAdapter(disadpt);
    mCursor.close();
}   
 }

And now the activity that displays the error:

public class AddActivity extends Fragment implements OnClickListener {
private Button btn_save;
private EditText edit_first,edit_last;
private DbHelper mHelper;
private SQLiteDatabase dataBase;
private String id,fname,lname;
private boolean isUpdate;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.add_activity, container, false);


    btn_save=(Button) view.findViewById(R.id.save_btn);
    edit_first=(EditText)view.findViewById(R.id.frst_editTxt);
    edit_last=(EditText)view.findViewById(R.id.last_editTxt);

   isUpdate=getActivity().getIntent().getExtras().getBoolean("update");
    if(isUpdate)
    {
        id=getActivity().getIntent().getExtras().getString("ID");
        fname=getActivity().getIntent().getExtras().getString("Fname");
        lname=getActivity().getIntent().getExtras().getString("Lname");
        edit_first.setText(fname);
        edit_last.setText(lname);

    }

     btn_save.setOnClickListener(this);

     mHelper=new DbHelper(getActivity());
    return view;

}

// saveButton click event 
public void onClick(View v) {
    fname=edit_first.getText().toString().trim();
    lname=edit_last.getText().toString().trim();
    if(fname.length()>0 && lname.length()>0)
    {
        saveData();
    }
    else
    {
        AlertDialog.Builder alertBuilder=new AlertDialog.Builder(getActivity());
        alertBuilder.setTitle("Invalid Data");
        alertBuilder.setMessage("Please, Enter valid data");
        alertBuilder.setPositiveButton("Ok", new DialogInterface.OnClickListener() {

            public void onClick(DialogInterface dialog, int which) {
            dialog.cancel();

            }
        });
        alertBuilder.create().show();
    }

}

/**
 * save data into SQLite
 */
private void saveData(){
    dataBase=mHelper.getWritableDatabase();
    ContentValues values=new ContentValues();

    values.put(DbHelper.KEY_FNAME,fname);
    values.put(DbHelper.KEY_LNAME,lname );

    System.out.println("");
    if(isUpdate)
    {    
        //update database with new data 
        dataBase.update(DbHelper.TABLE_NAME, values, DbHelper.KEY_ID+"="+id, null);
    }
    else
    {
        //insert data into database
        dataBase.insert(DbHelper.TABLE_NAME, null, values);
    }
    //close database
    dataBase.close();       

}
 }

This application works extending activity but my first time working with fragments has made me struggle.

If you would like any other information or classes please just let me know and i will provide it. Is it because it is not directly connected to the fragment and is being called from a follow-up class?.

Upvotes: 2

Views: 1642

Answers (2)

M D
M D

Reputation: 47807

You have got this error log

Caused by: java.lang.ClassCastException: app.norman.tennis.fours.AddActivity cannot be cast to android.app.Activity

It's becoz AddActivity is not a Activity class. Its a Fragment and you can not start a Fragment like activities.

Go to this more information: http://developer.android.com/reference/android/app/Fragment.html

Upvotes: 1

Raghunandan
Raghunandan

Reputation: 133560

Caused by: java.lang.ClassCastException: app.norman.tennis.fours.AddActivity cannot be cast to android.app.Activity

You have

 Intent i = new Intent(getActivity(),
                AddActivity.class);
 i.putExtra("update", false);
 startActivity(i);

And

  Intent i = new Intent(getActivity(),
                AddActivity.class);
   i.putExtra("Fname", user_fName.get(arg2));
        i.putExtra("Lname", user_lName.get(arg2));
        i.putExtra("ID", userId.get(arg2));
        i.putExtra("update", true);
        startActivity(i);

And this

 public class AddActivity extends Fragment implements OnClickListener {

AddActivity is not a Activity class. Its a fragment and you cannot start a fragment like the way you do for activities.

You need to add the fragment to the container. Fragment is hosted by a Activity.

So in your Activity xml have a container and add or replace fragment to it.

Example from the docs

Fragment newFragment = new ExampleFragment();
FragmentTransaction transaction = getFragmentManager().beginTransaction();

// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack
transaction.replace(R.id.fragment_container, newFragment);
transaction.addToBackStack(null);

// Commit the transaction
transaction.commit();

Upvotes: 2

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