Must include project R file

[Mike Tabak]

I'm fairly new to Android. I've done several small projects (in Eclipse Juno) and just started a new one. Up to now, I have not had to specifically import my project's R file. Suddenly, on my latest project, I must import the project's R file to resolve any of my layouts. Can anyone give me a clue as to why this might be? I have tried doing a clean on the project, but that did not help. I do not have android.R included anywhere to conflict. Thanks in advance - Mike

[Arun Kumarr]

The R stub file is automatically generated by your IDE?
You need to compile the Code and R stubs are automatically generated. Are there any other errors in your project?
Try to fix them and recompile your code.

[Arun Kumarr]

Again, may be it's stupid. You are doing a clean, but are you building it again?

[Ron McLeod]

Arun Kumarr wrote:The R stub file is automatically generated by your IDE?
You need to compile the Code and R stubs are automatically generated. Are there any other errors in your project?
Try to fix them and recompile your code.

I believe that he is referring to android.R, not the generated R.java file.

[Arun Kumarr]

Ah!! Yes. I think that is what he is mentioning.
In my computer my R file is present inside the jar "..sdk\platforms\android-22\android.jar" at the location android\R.class".
I use version 22 of the sdk. Hence 'android-22' in the directory path.

But wait! Are you not using any android development tool to develop?
If not, start using one. I use the Android Studio built on top of IntelliJ Idea IDE.
You can also use Eclipse for development. But Android Studio is the official supported development environment for android.
I suggest you migrate any old projects (if present) or develop any new projects using android studio.

[Mike Tabak]

Arun Kumarr wrote:Ah!! Yes. I think that is what he is mentioning.
In my computer my R file is present inside the jar "..sdk\platforms\android-22\android.jar" at the location android\R.class".
I use version 22 of the sdk. Hence 'android-22' in the directory path.

But wait! Are you not using any android development tool to develop?
If not, start using one. I use the Android Studio built on top of IntelliJ Idea IDE.
You can also use Eclipse for development. But Android Studio is the official supported development environment for android.
I suggest you migrate any old projects (if present) or develop any new projects using android studio.

Arun - Yes, the R.java file is being generated automatically and I did rebuild after my clean. I'm using the Android plugins for Eclipse. I'm going through the Big Nerd Ranch Android book which uses this environment. I'll probably stay with Eclipse for that reason until I finish the book and then switch over to Android Studio.

[Arun Kumarr]

Great. Can you post the error message and your code?

[Ron McLeod]

Mike Tabak wrote:I'm going through the Big Nerd Ranch Android book which uses this environment.

You application is probably needing android.R.layout.simple_list_item_1 as one of the parameters for an ArrayAdapter.

[Ron McLeod]

Is this what you are trying?

[Mike Tabak]

Arun Kumarr wrote:Great. Can you post the error message and your code?

There is no real error message other than Eclipse marking anything R.xxxx as unresolvable when you comment out the R.java import. Here are the files
that have the problem:

package com.bignerdranch.android.draganddraw;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;

import com.example.draganddraw.R;

public abstract class SingleFragmentActivity extends FragmentActivity {
    protected abstract Fragment createFragment();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_fragment);
        FragmentManager manager = getSupportFragmentManager();
        Fragment fragment = manager.findFragmentById(R.id.fragmentContainer);

        if (fragment == null) {
            fragment = createFragment();
            manager.beginTransaction()
                .add(R.id.fragmentContainer, fragment)
                .commit();
        }
    }
}

package com.bignerdranch.android.draganddraw;

// Page 515 - Creation - inflated R.layout.fragment_drag_and_draw

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.example.draganddraw.R;

public class DragAndDrawFragment extends Fragment {
	
	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup parent, 
								Bundle savedInstanceState) {
		View v = inflater.inflate(R.layout.fragment_drag_and_draw, parent, false);
		return v;
	} // end onCreateView

}

My main activity:

package com.bignerdranch.android.draganddraw;

import android.support.v4.app.Fragment;

// Page 514 - Creation

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

// Page 514 - Convert to extend SingleFragmentActivity from
// Fragment
public class DragAndDrawActivity extends SingleFragmentActivity {

	@Override
	public Fragment createFragment() {
		return new DragAndDrawFragment();
	}
	
}

Here is the R.java file:

/* AUTO-GENERATED FILE.  DO NOT MODIFY.
 *
 * This class was automatically generated by the
 * aapt tool from the resource data it found.  It
 * should not be modified by hand.
 */

package com.example.draganddraw;

public final class R {
    public static final class attr {
    }
    public static final class dimen {
        /**  Default screen margins, per the Android Design guidelines. 

         Customize dimensions originally defined in res/values/dimens.xml (such as
         screen margins) for sw720dp devices (e.g. 10" tablets) in landscape here.
    
         */
        public static final int activity_horizontal_margin=0x7f040000;
        public static final int activity_vertical_margin=0x7f040001;
    }
    public static final class drawable {
        public static final int ic_launcher=0x7f020000;
    }
    public static final class id {
        public static final int action_settings=0x7f080001;
        public static final int fragmentContainer=0x7f080000;
    }
    public static final class layout {
        public static final int activity_fragment=0x7f030000;
        public static final int fragment_drag_and_draw=0x7f030001;
    }
    public static final class menu {
        public static final int drag_and_draw=0x7f070000;
    }
    public static final class string {
        public static final int action_settings=0x7f050001;
        public static final int app_name=0x7f050000;
        public static final int hello_world=0x7f050002;
    }
    public static final class style {
        /** 
        Base application theme, dependent on API level. This theme is replaced
        by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
    

            Theme customizations available in newer API levels can go in
            res/values-vXX/styles.xml, while customizations related to
            backward-compatibility can go here.
        

        Base application theme for API 11+. This theme completely replaces
        AppBaseTheme from res/values/styles.xml on API 11+ devices.
    
 API 11 theme customizations can go here. 

        Base application theme for API 14+. This theme completely replaces
        AppBaseTheme from BOTH res/values/styles.xml and
        res/values-v11/styles.xml on API 14+ devices.
    
 API 14 theme customizations can go here. 
         */
        public static final int AppBaseTheme=0x7f060000;
        /**  Application theme. 
 All customizations that are NOT specific to a particular API-level can go here. 
         */
        public static final int AppTheme=0x7f060001;
    }
}

My manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.draganddraw"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="18" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.bignerdranch.android.draganddraw.DragAndDrawActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

[Jules Aglo]

I had this same problem a lot when I used Eclipse which is why switching to Android Studio might be the fastest solution.

[Arun Kumarr]

Can you check if the android jars are present in class path, in eclipse?

[Mike Tabak]

Arun Kumarr wrote:Can you check if the android jars are present in class path, in eclipse?

android.jar and android-support-v4.jar are in the path. I appear to have the same jars as another project which does not have this problem.

[Ron McLeod]

Can you restate the problem? It is unclear if there is actually something wrong, or you are just wondering why android.R and/or your project's R class is needed.

[Mike Tabak]

Ron McLeod wrote:Can you restate the problem? It is unclear if there is actually something wrong, or you are just wondering why android.R and/or your project's R class is needed.

The project acutally works file. The question is why I have to specifically import the R file in my sources. I normally don't have to do this. I created a new project today and did not have to import my R file. I don't recall specifically what I did when I created the project in question, but I noticed that the package for my source is "com.bignerdranch.android.draganddraw" and the R file is in the package "com.example.dragandgraw". So it's not in the same package - so I must import it. In the project I created today, the base source package is "com.bignerdranch.android.runtracker" and the R file is in the package "com.bignerdranch.android.runtracker". They are in the same package - no need to import R. The question now is what did I do in the previous project to get the R file in a different package?...I don't remember.

I guess this mystery is somewhat solved.