Question

Hi I’m having some problems to show a toast message, actually the program crash saying that I’m trying to disply a toast in the wrong thread or something like that.

I have been reading some other questions about the topic and I think the soultions is something like using a handler to comunicate with the UI, but not sure how to do it, could any one share with me an example/tutorial about how to launch a toast mesage from any part of the code?

For example I’m trying something like this: [the problematic line is between** **]

public class SamplesTiming extends Activity {
        ...

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

    }

        private void setButtonHandlers() {
                ((Button)findViewById(R.id.btnStart)).setOnClickListener(btnClick);
        ((Button)findViewById(R.id.btnStop)).setOnClickListener(btnClick);
        }

        private void enableButton(int id,boolean isEnable){
                ((Button)findViewById(id)).setEnabled(isEnable);
        }

        private void enableButtons(boolean isRecording) {
                enableButton(R.id.btnStart,!isRecording);
                enableButton(R.id.btnStop,isRecording);
        }



        private void startRecording(){

                              ...

                recordingThread = new Thread(new Runnable() {

                        //@Override
                        public void run() {

                                writeAudioDataToFile();
                        }
                },"AudioRecorder Thread");

                recordingThread.start();
        }


        private void writeAudioDataToFile(){

               ...

                while(isRecording){

                             ...

                        read = recorder.read(data, 0, bufferSize);


                        if(condition) **Toast.makeText(getApplicationContext(), 
                           "it happen", Toast.LENGTH_LONG).show();**

                            ...

                        }                       


        }

        private void stopRecording(){
                if(null != recorder){
                        isRecording = false;

                        recorder.stop();
                        recorder.release();

                        recorder = null;
                        recordingThread = null;
                }                  

        }


        private View.OnClickListener btnClick = new View.OnClickListener() {
               // @Override
                public void onClick(View v) {
                        switch(v.getId()){
                                case R.id.btnStart:{



                                    enableButtons(true);
                                        startRecording();

                                        break;
                                }
                                case R.id.btnStop:{


                                        enableButtons(false);
                                        stopRecording();

                                        break;
                                }
                        }
                }
        };
}

Thank you very much for your time

Answer 1

use Activity.runOnUiThread for showing Toast from background thread as :

while(isRecording){

......

SamplesTiming.this.runOnUiThread(new Runnable() {
    public void run() {
         // show toast here
         Toast.makeText(SamplesTiming.this, 
            "it happen", Toast.LENGTH_LONG).show();
    }
});
.....

}