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Codelaby
Asked: 2020-05-11 05:14:57 +0800 CST 2020-05-11 05:14:57 +0800 CST

Error Only the original thread that created a view hierarchy can touch its views. on Android

  • 772

After Android-Studioit warned me that there is too much load to the main thread.

Skipped 113 frames: the application may be doing too much work on its main thread

I have created a runnable to launch a thread with some processes:

new Thread(new Runnable() {
    @Override
    public void run() {
       UpdateUI(); //Actualiza datos de la Interfaz de usuario
    }
}

But it returns the error:

Only the original thread that created a view hierarchy can touch its views.

I've searched SO and you can launch a thread

getActivity().runOnUiThread(new Runnable() {
    @Override
    public void run() {
       //Cambiar controles
    }
});

But since I have to do a lot of checks or else a thread is executed at the same time, it returns the main thread overload. I even notice that the side menu slows down when it closes.

How do you make a thread but be able to access interface elements in order to modify their data or state?

java

2 Answers

  1. Best Answer

    To fix the error:

    Only the original thread that created a view hierarchy can touch its views.

    You can resort to runOnUIThreador AsyncTaskdepending on the task to be performed, if it requires a lot of process directly toAsyncTask

    runOnUiThread to run a thread with access to interface elements:

    getActivity().runOnUiThread(new Runnable() {
    @Override
    public void run() {
       //Cambiar controles
    }
});

    AsyncTask

    To execute a task that consumes a lot, and keep the user informed of the process and at the end refresh the UI:

    • on doInBackgroundhomework

    The following allow you to interact with the UI elements

    • In onProgressUpdateto report your progress
    • On onPostExecuteat the end refresh the UI.

    Example of an AsyncTask:

    private class myUpdateAsyncTask extends AsyncTask<Intent, Integer, Boolean> {

        private Context mContext;
        private String title;

        public myUpdateAsyncTask (Context context) {
            this.mContext = context;
        }


        @Override
        protected Boolean doInBackground(Intent... intents) {
            //@Todo Tarea a procesar
            title = "soy un titulo asyncTask"
            publishProgress(1); //Para mandar control para actualizar la UI
        }

        @Override
        protected void onProgressUpdate(Integer... values) {
            //@Todo values[0] para obtener el código de control, actualizar la UI
            if (values[0]==1) textView.setText(title)
        }

        @Override
        protected void onPostExecute(Boolean result) {
            super.onPostExecute(result);

            if (result) {
                //@Todo AsyncTask finalizado
            }
        }

    }

    Some advices

    • Look at creating control variables, if more than one process needs to obtain a value from the same function.
    • Only update the elements of the interface that require it, using numerical control variables you can predetermine which ones they affect.
    • 6

  2. I had a similar problem and solved it as follows in this example in the event handler code:

        private void Ws_OnOpened()
    {
        Device.BeginInvokeOnMainThread(
            () =>
            {
                ws.Send(@"{""protocol"":""json"",""version"":1}" + recordSeparator);
                lblStatus.Text = "WS abierto";
                ws.Send("{\"arguments\":[\"" + "444" + "-1\"],\"invocationId\":\"" + "0" + "\",\"target\":\"JoinGroup\",\"type\":1}" + recordSeparator);
            }
            );
    }
    • 0