无法在Android Studio第一个应用程序中解析符号setTextSize，setText，addView

Question

I am creating my first app using Android Studio. I have followed the instructions in http://developer.android.com/training/basics/firstapp/starting-activity.html#DisplayMessage but I am getting multiple cannot resolve symbol error for setTextSize, setText and addView . I have imported TextView using alt+Enter but still getting the error. I am a newbie to this and would appreciate any help. Thanks in advance. I am including my DisplayMessageActivity.java

package com.deepdil.hello;
import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.RelativeLayout;
import android.widget.TextView;


public class DisplayMessageActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_display_message);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
TextView textView= new TextView(this);
textView.setTextSize(40);
textView.setText(message);
RelativeLayout layout = (RelativeLayout) findViewById(R.id.content);
layout.addView(textView);
}

Answer 1

You have to place your Code inside the onCreate or another java method that is called inside of your onCreate method.

Java is not a functional programming language so you have to place this code inside of a method.

Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
TextView textView= new TextView(this);
textView.setTextSize(40);
textView.setText(message);
RelativeLayout layout = (RelativeLayout) findViewById(R.id.content);
layout.addView(textView);