Chris Melton Chris Melton - 4 months ago 35
Android Question

Unable to change text of TextView inside of a Fragment from same activity

I am trying to change a TextView to give the status of a Bluetooth connection within a Fragment, but nothing seems to happen when

msgReceived.setText(string)
is called. How would I go about doing this? Here is my Java file for the Fragment:

package dleedesign.dubcommunicationstestapp;

import android.app.Fragment;
import android.bluetooth.BluetoothAdapter;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;

public class SecondFragment extends Fragment implements View.OnClickListener {

View myView;

public final String TAG = "Main";
private Bluetooth bt;
public Button sendCommand;
public TextView msgReceived;

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

sendCommand = (Button) inflater.inflate(R.layout.second_layout, container, false).findViewById(R.id.sendCommand);
msgReceived = (TextView) inflater.inflate(R.layout.second_layout, container, false).findViewById(R.id.msgReceived);
msgReceived.setText("Ready to connect");

bt = new Bluetooth(new MainActivity(), mHandler);
connectService();

return myView;
}

@Override
public void onClick(View v)
{
connectService();
}

public void connectService()
{
try {
msgReceived.setText("Connecting...");
BluetoothAdapter btAdapter = BluetoothAdapter.getDefaultAdapter();
if(btAdapter.isEnabled())
{
bt.start();
bt.connectDevice("HC-06");
Log.d(TAG, "Btservice started- listening");
msgReceived.setText("Connected!");
}
else
{
Log.w(TAG, "Btservice started - bluetooth is not enabled");
msgReceived.setText("Bluetooth not enabled");
}
} catch (Exception e) {
Log.e(TAG, "Unable to start bluetooth", e);
msgReceived.setText("Unable to connect: " + e);
}
}

private final Handler mHandler = new Handler()
{
@Override
public void handleMessage(Message msg)
{
switch (msg.what)
{
case Bluetooth.MESSAGE_STATE_CHANGE:
Log.d(TAG, "MESSAGE_STATE_CHANGE: " + msg.arg1);
break;
case Bluetooth.MESSAGE_WRITE:
Log.d(TAG, "MESSAGE_WRITE");
break;
case Bluetooth.MESSAGE_READ:
Log.d(TAG, "MESSAGE_READ");
break;
case Bluetooth.MESSAGE_DEVICE_NAME:
Log.d(TAG, "MESSAGE_DEVICE_NAME " + msg);
break;
case Bluetooth.MESSAGE_TOAST:
Log.d(TAG, "MESSAGE_TOAST " + msg);
break;
}
}
};

}


EDIT:
Here is the LogCat message that spits out when I select the SecondFragment:

dleedesign.dubcommunicationstestapp D/BluetoothService: Bounded device 40:EF:4C:C2:A9:32
dleedesign.dubcommunicationstestapp D/BluetoothService: Bounded device 98:D3:31:70:80:C5
dleedesign.dubcommunicationstestapp D/BluetoothService: start
dleedesign.dubcommunicationstestapp D/BluetoothService: setState() 0 -> 1
dleedesign.dubcommunicationstestapp W/BluetoothAdapter: getBluetoothService() called with no BluetoothManagerCallback
dleedesign.dubcommunicationstestapp D/BluetoothService: Socket Type: nullBEGIN mAcceptThreadThread[Thread-20627,5,main]
dleedesign.dubcommunicationstestapp D/BluetoothService: connect to: 98:D3:31:70:80:C5
dleedesign.dubcommunicationstestapp D/BluetoothService: setState() 1 -> 2
dleedesign.dubcommunicationstestapp D/Main: Btservice started- listening
dleedesign.dubcommunicationstestapp I/BluetoothService: BEGIN mConnectThread SocketType:null
dleedesign.dubcommunicationstestapp W/BluetoothAdapter: getBluetoothService() called with no BluetoothManagerCallback
dleedesign.dubcommunicationstestapp D/Main: MESSAGE_STATE_CHANGE: 1
dleedesign.dubcommunicationstestapp D/Main: MESSAGE_STATE_CHANGE: 2
dleedesign.dubcommunicationstestapp E/BluetoothService: Unable to connect socket
java.io.IOException: read failed, socket might closed or timeout, read ret: -1
at android.bluetooth.BluetoothSocket.readAll(BluetoothSocket.java:517)
at android.bluetooth.BluetoothSocket.readInt(BluetoothSocket.java:528)
at android.bluetooth.BluetoothSocket.connect(BluetoothSocket.java:320)
at dleedesign.dubcommunicationstestapp.Bluetooth$ConnectThread.run(Bluetooth.java:408)
dleedesign.dubcommunicationstestapp D/BluetoothService: start
dleedesign.dubcommunicationstestapp D/BluetoothService: setState() 2 -> 1
dleedesign.dubcommunicationstestapp D/Main: MESSAGE_TOAST { when=-15ms what=5 target=dleedesign.dubcommunicationstestapp.SecondFragment$1 }
dleedesign.dubcommunicationstestapp D/Main: MESSAGE_STATE_CHANGE: 1

Answer

Whats happening is you're trying to inflate a view with a given layout each time you do findViewById and then casting it to a TextView. This is calling findViewById on a different view then you're returning. You should first inflate the layout as you did in the first line with

myview = inflater.inflate....

and then,

msgReceived = (TextView) myView.findViewById(R.id.msgReceived);

(Same with any other TextView, Button etc you are trying to use)