main cannot be resolved or is not a field

Question

This error occurs in setContentView line in this code snippet:

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

I understand that in order for R.layout.main to be resolved, a file named res/layout/main.xml must be present.

It is present and valid (i.e. Eclipse marks it as perfect without any errors). So, what else could cause this error?

BTW, I already tried Project > Clean. The error persists.

score 140 · Accepted Answer · answered Feb 28 '11 at 14:43

140

Make sure you don't have this in your imports:

import android.R;

but:

import your.application.packagename.R;

answered Feb 28 '11 at 14:43

Cristian

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you are king. I replaced **import android.R;** with **import com.example.ch15_1_simple_tts_demo.R;** and that cleaned all errors but introduced a new one: "The declared package "" does not match the expected package package com.example.ch15_1_simple_tts_demo". Fortunately, Eclipse is like a bike with training wheels so it suggested adding a package declaration at the beginning of the .java file. So many fine details... You would think that in the 21st century programming for android would be different than writing assembly code for the 8088. – Android Eve Feb 28 '11 at 15:08
11

For me I only needed to delete the "import android.R;" – DonnaLea Sep 05 '11 at 04:36
2

That's because you were inside a class that belongs to the same package of your `R` class. – Cristian Sep 05 '11 at 13:30
I don't have any of these statements in my app. – Hafiz May 23 '12 at 10:00
If I add `import com.example.AndroidHello.R;` I get error "import ... cannot be resolved". What should I do ? – Buksy Nov 01 '12 at 22:46
In the example I said: `your.application.packagename.R`, but you have insead `your.application.packagename.YourClassName.R` which is wrong. – Cristian Nov 02 '12 at 16:25

score 10 · Answer 2 · answered Nov 05 '11 at 22:42

10

Also try: add

import your.application.packagename.R;

and run: eclipse->project->clean..

The error should be gone.

answered Nov 05 '11 at 22:42

giorgioca

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score 2 · Answer 3 · edited Jun 04 '12 at 11:12

If this is the problem you are encountering then check at the top of your code - you will see:

import android.R

Delete that line and and change it into

import (com.xx.yy)

Replace (com.xx.yy) with your actual package name for the class. This problem occurs mainly when you copy all the XML and Java code of another application and paste it into your new application.

This is an example of how I replaced the android.R packages within one of my own apps (a puzzle game):

package com.pir.PUZZLEGAME_NEW;

import com.pir.PUZZLEGAME_NEW.*;
import com.pir.puzzlegame_old.R;

Good luck!

score 2 · Answer 4 · edited Jul 23 '12 at 06:48

2

Delete all your import statements from the class where you are getting this error message.

Then press ctrl+shift+o

edited Jul 23 '12 at 06:48

Tisho

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answered Jul 23 '12 at 04:41

yogesh

21
1

score 1 · Answer 5 · answered Jan 09 '13 at 12:24

1

I changed

   import android.R;

to

 import your.application.packagename.R;

And project ->clean still the error.

But when I Run the project the error automatically gone, may be Eclipse problem.

answered Jan 09 '13 at 12:24

Haris

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score 1 · Answer 6 · answered Dec 17 '13 at 07:58

1

for me changing

import org.opencv.R;

to

import com.example.opencvtryagain.R;

solved it, where as my package name was com.example.opencvtryagain;

answered Dec 17 '13 at 07:58

Engr Muhammad Zohaib

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I faced same issue with my menu resource file. Thanks for saving my time – Yogesh Srivastava Apr 01 '22 at 05:04

score 0 · Answer 7 · answered Jun 11 '12 at 21:04

If you are using eclipse, then

Delete all your import statements from the class where you are getting this error message.
press CTRL + SHIFT + O --> OR select Source from menu and select Organize import. This will import all the necessary classes.

Note: Since you have a local R.class file, it will import your local file instead of the android.R file.

Hope this will help someone.

score 0 · Answer 8 · answered Dec 04 '12 at 07:59

0

I have removed the following line and it worked for me.

import android.R;

answered Dec 04 '12 at 07:59

dev_android

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score 0 · Answer 9 · answered Nov 04 '11 at 23:23

0

Also, sometimes it still won't compile even after making that needed change; but if you go ahead and run the app, the errs will clear up.

answered Nov 04 '11 at 23:23

B. Clay Shannon-B. Crow Raven

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main cannot be resolved or is not a field

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