title: NullPointerException when setting text of TextView
body: <p>I am trying to make a simple game. When I am trying to set the text of 3 <code>TextViews</code> I get a <code>NullPointerException</code>.</p>
  
  <pre><code>public class MainActivity extends Activity implements View.OnClickListener {
  
  private void initRound() {
      countdown = 10;
  
      ViewGroup container = (ViewGroup) findViewById(R.id.container);
      container.removeAllViews();
      WimmelView wv = new WimmelView(this);
      container.addView(wv, ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
      wv.setImageCount(8*(10 + round));
  
      fillTextView(R.id.points, Integer.toString(points));
      fillTextView(R.id.round, Integer.toString(round));
      fillTextView(R.id.countdown, Integer.toString(countdown*1000));
  }
  
  private void fillTextView(int id, String text) {
      TextView tv = (TextView) findViewById(id);
      tv.setText(text);  //HERE DO I GET THE EXCEPTION
  }
  
  }
  </code></pre>
  
  <p>Here is the error from logcat:</p>
  
  <pre><code>E/AndroidRuntime﹕ FATAL EXCEPTION: main
  Process: com.developer.nico.kissthefrognow, PID: 1940
  java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
          at com.developer.nico.kissthefrognow.MainActivity.fillTextView(MainActivity.java:80)
          at com.developer.nico.kissthefrognow.MainActivity.initRound(MainActivity.java:34)
          at com.developer.nico.kissthefrognow.MainActivity.newGame(MainActivity.java:21)
          at com.developer.nico.kissthefrognow.MainActivity.startGame(MainActivity.java:67)
          at com.developer.nico.kissthefrognow.MainActivity.onClick(MainActivity.java:58)
          at android.view.View.performClick(View.java:4756)
          at android.view.View$PerformClick.run(View.java:19749)
          at android.os.Handler.handleCallback(Handler.java:739)
          at android.os.Handler.dispatchMessage(Handler.java:95)
          at android.os.Looper.loop(Looper.java:135)
          at android.app.ActivityThread.main(ActivityThread.java:5221)
          at java.lang.reflect.Method.invoke(Native Method)
          at java.lang.reflect.Method.invoke(Method.java:372)
          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
  </code></pre>
  
  <p>And my xml:</p>
  
  <pre><code>&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
  android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
  android:paddingRight="@dimen/activity_horizontal_margin"
  android:paddingTop="@dimen/activity_vertical_margin"
  android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"
  android:id="@+id/rl"&gt;
  
  &lt;FrameLayout
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:id="@+id/container"&gt;
  
      &lt;TextView
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="000000"
          android:id="@+id/points"
          android:layout_gravity="left|top"
          android:textColor="@color/Red" /&gt;
  
      &lt;TextView
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="0"
          android:id="@+id/round"
          android:layout_gravity="right|top"
          android:textColor="@color/Red" /&gt;
  
      &lt;TextView
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="00000"
          android:id="@+id/countdown"
          android:layout_gravity="center_horizontal|bottom"
          android:textColor="@color/Red" /&gt;
  &lt;/FrameLayout&gt;
  </code></pre>
  
  <p></p>
  
  <p>Any ideas how to solve it? Thanks!</p>