title: (Android) findViewById Fails to locate the view and returns null?
body: <p>So I just started learning Android and I am reading the commonsware android development guide as a starting point. So basically I tried to create a view using xml and this xml is located in </p>
  
  <pre><code>res/layout/edittext.xml
  </code></pre>
  
  <p>and the xml looks like:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8" ?&gt;
  &lt;EditText xmlns:android="http://schemas.android.com/apk/res/android"
            android:id="@+id/field"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:singleLine="false"/&gt;
  </code></pre>
  
  <p>and my code</p>
  
  <pre><code>public class HelloWorld extends Activity implements View.OnClickListener {
  
      Button btn;
  
      /**
       * Called when the activity is first created.
       */
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          System.out.println("HEY");
  
          btn = new Button(this);
          EditText editText = (EditText) findViewById(R.id.field);
  
          editText.setText("Hey there how are you doing");
          updateTime();
          setContentView(R.layout.main);
      }
  
      public void onClick(View view) {
          updateTime();
      }
  
      public void updateTime() {
          btn.setText(new Date().toString());
      }
  }
  </code></pre>
  
  <p>and the editText returns null... This is R class if it matters.</p>
  
  <pre><code>/* 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.dennis;
  
  public final class R {
      public static final class attr {
      }
      public static final class drawable {
          public static final int icon=0x7f020000;
      }
      public static final class id {
          public static final int field=0x7f050000;
          public static final int helloText=0x7f050001;
      }
      public static final class layout {
          public static final int edittext=0x7f030000;
          public static final int main=0x7f030001;
      }
      public static final class string {
          public static final int app_name=0x7f040000;
      }
  }
  </code></pre>
  
  <p>stack trace</p>
  
  <pre><code>07-22 11:30:46.670: ERROR/AndroidRuntime(674): FATAL EXCEPTION: main
          java.lang.RuntimeException: Unable to start activity ComponentInfo{com.dennis/com.dennis.HelloWorld}: java.lang.NullPointerException
          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
          at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
          at android.app.ActivityThread.access$2300(ActivityThread.java:125)
          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
          at android.os.Handler.dispatchMessage(Handler.java:99)
          at android.os.Looper.loop(Looper.java:123)
          at android.app.ActivityThread.main(ActivityThread.java:4627)
          at java.lang.reflect.Method.invokeNative(Native Method)
          at java.lang.reflect.Method.invoke(Method.java:521)
          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
          at dalvik.system.NativeStart.main(Native Method)
          Caused by: java.lang.NullPointerException
          at com.dennis.HelloWorld.onCreate(HelloWorld.java:25)
  </code></pre>