title: Problem with setLayoutParams method in android UI
body: <p>I am making an application in which I have to change the UI programmaticaly.
  I needed to change the <code>layout_height</code> and <code>layout_width</code> XML attributes.</p>
  
  <p>But when I use the <code>setLayoutParams</code> method, the app runs and then I give a message that it has unexpectedly stopped working and I have to force close.</p>
  
  <p>I have tried setting the LayoutParams as <code>ViewGroup.LayoutParams</code> as well.
  But nothing works. Kindly check the attached code and guide.</p>
  
  <p>This is the Java Code.</p>
  
  <pre><code>private void fixLayoutVmain(){
      ListView lv;
      ImageButton rev,stop,play,forw;
      lv=(ListView)findViewById(R.id.ListMain);
      rev=(ImageButton)findViewById(R.id.rev);
      stop=(ImageButton)findViewById(R.id.stop);
      play=(ImageButton)findViewById(R.id.plpa);
      forw=(ImageButton)findViewById(R.id.forw);
      Log.d("DEV1","ID's have been assigned");
      LayoutParams lp=new LayoutParams(W, ((75*H)/100));      
      Log.d("DEV1","param object created");       
      lv.setLayoutParams(lp);     
      Log.d("DEV1","ListView param set");     
      lp.height=(int)(10*H)/100;
      lp.width=(int)(10*H)/100;
      Log.d("DEV1","Changes to param made");
      rev.setLayoutParams(lp);    
      Log.d("DEV1","Reverse Button param applied");
      stop.setLayoutParams(lp);
      Log.d("DEV1","Stop button param applied");
      play.setLayoutParams(lp);
      Log.d("DEV1","forward button param applied");
      forw.setLayoutParams(lp);
      Log.d("DEV1","All imagebutton changes have been made");
  
  }
  </code></pre>
  
  <p>This is the XML File</p>
  
  <pre><code>&lt;LinearLayout
      android:orientation="vertical"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"&gt;
      &lt;ListVieW
          android:id="@+id/ListMain"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content" /&gt;
          &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="horizontal"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent"
              android:gravity="bottom"&gt;
              &lt;ImageButton
                  android:id="@+id/rev"
                  android:src="@drawable/reverseimg"
                  android:background="@null"
                  android:scaleType="fitXY" /&gt;
              &lt;ImageButton
                  android:id="@+id/stop"
                  android:src="@drawable/stopimg"
                  android:background="@null"
                  android:scaleType="fitXY" /&gt;
              &lt;ImageButton
                  android:id="@+id/plpa"
                  android:src="@drawable/playimg"
                  android:background="@null"
                  android:scaleType="fitXY" /&gt;
              &lt;ImageButton
                  android:id="@+id/forw"
                  android:src="@drawable/forwardimg"
                  android:background="@null"
                  android:scaleType="fitXY" /&gt;
      &lt;/LinearLayout&gt;
  &lt;/LinearLayout&gt;
  </code></pre>