R.Java在我的项目中缺失，不会再生

Question

I've began making a new project and just as I was linking my buttons to the java I noticed my R would not resolve and come to find out that my R.java file is not there. I've looked at other questions like this and they say to clean the project which I have done and it still does not work. Here is my code from the pages where it wont resolve. Thanks!

Invoice Java

package com.invoice;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;

public class InvoiceActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.splash);
        Thread logoTimer = new Thread(){
            public void run(){
                try{
                    sleep(5000);
                    Intent menuIntent = new Intent("com.invoice.MENU");
                    startActivity(menuIntent);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                finally{
                    finish();
                }
            }
        };
        logoTimer.start();
    }
}

Job.java

package com.invoice;


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

public class Job extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.job);
    }
}

menu.java

package com.invoice;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class menu extends Activity{
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Button job = (Button) findViewById(R.id.button4);
        job.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                startActivity(new Intent("com.invoice.job"));

            }
        });
    }

    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        super.onPause();
    }
}

Answer 1

You probably have an error in an xml file. R.java will not be generated if there are xml errors. Look through you Manifest.xml and all your layout, values, and any other xml files in res.

Once you have found and fixed the error, clean the project.

Answer 2

You probably have problem in resource folder, first solve that error.numeric name of image can generate errors.After solving the errors just clean your project or Build your Project. R.java build again if error is fixed.