How to textView.setText from Thread?

Question

I need to set text to textView from thread. All code is created in oncreate()

something like

public TextView pc;

    oncreate(..) {
        setContentView(R.layout.main);
        pc = new TextView(context);
        Thread t =new Thread() {
            public void run() {
                pc.setText("test");
        }};
        t.start();

This crashes my app. How can I set text from thread?

Answer 1

Use a Handler:

public TextView pc;
Handler handler = new Handler();
oncreate(..) {
    setContentView(R.layout.main);
    pc = new TextView(context);
    Thread t =new Thread(){
        public void run() {
            handler.post(new Runnable() {
                public void run() {
                    pc.setText("test");
                }
            });
        }
    }};
    t.start();
}

But you have another problem. pc points to a view that is not part of your hierarchy. You probably want to use findViewById with the id of the TextView in your layout.

Answer 2

Try Activity.runOnUiThread().

Thread t = new Thread() {
    public void run() {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                pc.setText("test");
            }
        });
    }
};