Android Dev problems with android.R

Question

I am having trouble linking my interface with my java.

    package com.example.game;

import android.os.Bundle;
import android.R;
import android.app.Activity;
import android.view.Menu;
import android.widget.Button;

public class MainActivity extends Activity {

   Button btn1 = (Button) findViewById(R.id.button1);


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

    @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); <--- main
        return true;
    }

}

I am having trouble with the layout. I can link my buttons ect. but it always throws an error on the generated code? why does it do this? I did the suggested fixes and ran it, which resulted into a crash... I am new to java and android development. I am learning as I go. I do have other experience in visual basic and what not.

Suggested fixes: change to activity_list_ item and can not be resolved.

Answer 1

Your btn1 assignment is incorrect. When you're assigning it on initialization, there is no view, as the code is run prior to onCreate. Instead, it should look like this:

Button btn1;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main); <---- activity_main
    btn1 = (Button) findViewById(R.id.button1);
}