问getApplicationContext()错误

EN

package com.androidbegin.absfragtabhost;

import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.app.Fragment;
import android.app.Activity;
import android.telephony.SmsManager;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class FragmentTab3 extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragmenttab3, container, false);
    super.onCreate(savedInstanceState);
    //setContentView(R.layout.activity_main);

    sendBtn = (Button) rootView.findViewById(R.id.btnSendSMS);
    txtphoneNo = (EditText) rootView.findViewById(R.id.editTextPhoneNo);
    txtMessage = (EditText) rootView.findViewById(R.id.editTextSMS);

    sendBtn.setOnClickListener(new View.OnClickListener() {
        public void onClick(View view) {
            sendSMSMessage();
        }
    });

    return rootView;
}



    Button sendBtn;
    EditText txtphoneNo;
    EditText txtMessage;



    protected void sendSMSMessage() {
        Log.i("Send SMS", "");

        String phoneNo = txtphoneNo.getText().toString();
        String message = txtMessage.getText().toString();

        try {
            SmsManager smsManager = SmsManager.getDefault();
            smsManager.sendTextMessage(phoneNo, null, message, null, null);
            Toast.makeText(getApplicationContext(), "SMS sent.",
                    Toast.LENGTH_LONG).show();
        } catch (Exception e) {
            Toast.makeText(getApplicationContext(),
                    "SMS failed, please try again.",
                    Toast.LENGTH_LONG).show();
            e.printStackTrace();


        }
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }


}