i found out that my R.java contains nothing, can someone tell me what to be written in R.java

Question

error is that, R is underlined red! and com.example.guessthenumber.R is also underlined red! when hovered it says to create a class R in package com.example.guessthenumber.R

xml file:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/Guess"
    android:gravity="start"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/button1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:text="Done!" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/imageView1"
        android:layout_centerHorizontal="true"
        android:text="Enter your guessed number below"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:textColor="#191970"
        android:textStyle="bold" />

    <EditText
        android:id="@+id/editText1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textView1"
        android:layout_centerVertical="true"
        android:text="0"
        android:inputType="number" />

    <TextView
        android:id="@+id/textView1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/button1"
        android:layout_below="@+id/editText1"
        android:layout_marginTop="29dp"
        android:fontFamily="sans-serif-condensed"
        android:text="@string/guess"
        android:textColor="#000000"
        android:textSize="22sp"
        android:textStyle="bold" />

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:src="@drawable/game" />

</RelativeLayout>

below one is the java file:

package com.example.guessthenumber;

import android.os.Bundle;
import com.example.guessthenumber.R 
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final TextView t1 = (TextView) findViewById(R.id.textView1);
        final TextView guessText = (TextView) findViewById(R.id.textView2);
        final EditText userGuess = (EditText) findViewById(R.id.editText1);

        Button b1 = (Button) findViewById(R.id.button1);

        final String[] myNames={"Shashank","Sarthak","Gowda","$hankar"};


        b1.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                String randText="";
                // TODO Auto-generated method stub

                int rando = (int) (Math.random()* 6);
                int userNumber = Integer.parseInt(userGuess.getText().toString());

                if(userNumber == rando){
                    guessText.setText("You got it right!");
                }else{
                    guessText.setText("Guess again! :(");
                }

                randText=Integer.toString(rando);
                t1.setText(randText);   

                userGuess.setText("0");
            }
        });

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

Answer 1

Replace:
import android.R; by

import com.example.guessthenumber.R  

OR

remove import.android.R and use ctrl+shift+O, organise imports if you are using eclipse.

Clean, build your project.

Also, pls read more about R:
Android: What is R? Why is it so Cryptic?

Check your imports - at the top of your activity, below your package name. And make sure it has something like this line:

import your_application_package_name.R;

---

Agreed with gunar's comment above,

In your xml, the "id" has not been defined properly, for your TextView. Please post the xml code, may be the activity's too.

Correct way for "id" in TextView, xml :

<TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

Answer 2

Check that you are importing the R class from your package and not the Android's one. Check also that your resources do not contains error, otherwise the R class will not be generated.