利用Thread和Headler 将TextView修改

private TextView mtext;Handler handler = new Handler() {    @Override    public void handleMessage(Message msg) {        super.handleMessage(msg);        switch (msg.what) {            case 1:                mtext.setText("我在学习Android");                break;            case 2:                startActivity(new Intent(MainActivity.this,Main2Activity.class));                break;        }    }
};
//Thread
new Thread() {    @Override    public void run() {        super.run();        try {            Thread.sleep(2000);            handler.sendEmptyMessage(1);            Thread.sleep(2000);            handler.sendEmptyMessage(2);        } catch (InterruptedException e) {            e.printStackTrace();        }    }}.start();