android “main cannot be resolved or is not a field”

Question

im new to this platform, please help me to find what is the error...
setContentView(R.layout.main); // this line shows the error.

Code:

package com.example.helloandroid;

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

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

Answer 1

尝试删除import android.R行，然后清理您的项目。

Answer 2

Just adding more details on why the error is coming.

As there is an import of android.R so setContentView() is looking for a layout file 'android.R.layout.main' and there is no main.xml in the layout files that come along with SDK. So, using the correct R.java import will work.

Answer 3

clean Project then try To Run because i faced same problem before a month and remember layout/main.xml must be their and it must not contains any error. you can Also Do this

import android.R; or
import your.application.packagename.R; Now Clear Project and Run it.

Answer 4

You must have to simply change the

setContentView(R.layout.main);

... to:

setContentView(R.layout.activity_main);

... because Layout contains this .xml file.

I hope your problem will be solved.

Answer 5

First remove import android.R;

After any change on xml fiels you must clean project.

Build > Clean Project

after that every things corrects.