AlertDialog.Builder RuntimeException

Question

I am try to add a dialog into BluetoothChatService that will prompt to retry the Bluetooth connection if the connection cannot be made or is lost. I am getting a runtime exception when AlertDialog.show() is executed; this error is occurring in Handler.java with the error "Can't create handler inside thread that has not called Looper.prepare()" and mLooper is null. I've tried other solutions found at stackoverflow, such as 'new AlertDialog.Builder(Activity.this)'; nothing has worked.

EDIT: It seems that the approach of a dialog within a thread is the issue. I will re-code the dialog within the constraints of the UI Activity that is creating the thread. Thanks to all that responded.

The code:

public class BluetoothChatService {

private Context context;
private final BluetoothAdapter mAdapter;
private int mState;

public BluetoothChatService(Context context) {
    this.context = context;
    mAdapter = BluetoothAdapter.getDefaultAdapter();
    mState = STATE_NONE;
}

private void connectionFailed(String s) {
    // Send a failure message back to the Activity
    stop();
    sendToastMessage(String.format(context.getApplicationContext().getString(R.string.bluetooth_cannot_connect), s));
    createRetryDialog(R.string.bluetooth_cannot_connect, s);
}

// ---------------------------------------------------------------------------------------------
private void createRetryDialog(int msg_id, String err_msg) {
    AlertDialog.Builder alertDialogBuilderRetry;
    alertDialogBuilderRetry = new AlertDialog.Builder(context);
    String message = String.format(context.getApplicationContext().getString(msg_id), err_msg);

    // set title
    alertDialogBuilderRetry.setTitle(context.getApplicationContext().getString(R.string.bluetooth_title_connect_error));

    // set dialog message
    alertDialogBuilderRetry
        .setMessage(message)
        .setCancelable(false)
        .setPositiveButton(context.getApplicationContext().getString(R.string.dialog_button_yes), new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int id) {
                // Start the service over to restart listening mode
                initializeBluetooth();
                dialog.dismiss();
            }
        })
        .setNegativeButton(context.getApplicationContext().getString(R.string.dialog_button_no),new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int id) {
                // if this button is clicked, just close
                // the dialog box and do nothing
                mState = STATE_NONE;
                dialog.cancel();
            }
        }).create().show();
}
}

You can't create or show dialog in Service.. Only the Main UI thread can do this.. — user370305, Sep 04 '12 at 13:07
I see you've put this work into its own class. Can you post the code where you are making use of this class? It seems like you might be trying to do it from a service, or a background thread instead of the UI thread. — FoamyGuy, Sep 04 '12 at 13:12

Eldhose M Babu · Accepted Answer · 2012-09-04T13:17:29.387

0

Make sure when you call this, you are passing in activity context, not application context. Dialogs cannot be shown using applicationcontext.

edited Sep 04 '12 at 13:17

answered Sep 04 '12 at 13:10

Eldhose M Babu

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he isn't using the `context.getApplicationContext()` notation for the dialog.builder constructor. He is only using it to pull Strings from his resources. (Surely there is a better way then with getApplicationContext()), but either way this comment is irrelevant to the actual dialog being shown. – FoamyGuy Sep 04 '12 at 13:14

AlertDialog.Builder RuntimeException

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