[Android] Why inflate Other View over but can not fill the parent layout ?

Want to design a FrameLayout, which has a WebView, WebView stacked with a transparent top LinearLayout (id is middleLayout), while in the case of no network will LinearLayout becomes opaque , blocking WebView, prompt the user can not be networked .

layout is as follows:

  <?xml version="1.0" encoding="utf-8"?>
  <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:orientation="vertical" >
  
      <WebView
          android:id="@+id/detailWebView"
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"
          android:layout_marginTop="48dip" />
  
      <LinearLayout
          android:id="@+id/middleLayout"
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"
          android:layout_marginTop="48dip"
          android:background="#00000000"
          android:orientation="vertical" />
  
      <LinearLayout
          android:layout_width="fill_parent"
          android:layout_height="48dip"
          android:layout_gravity="top"
          android:background="@drawable/title_bg"
          android:orientation="horizontal" >
  
          <ImageButton
              android:id="@+id/back"
              android:layout_width="48dip"
              android:layout_height="fill_parent"
              android:background="#00000000"
              android:scaleType="fitCenter"
              android:src="@drawable/back" />
      </LinearLayout>
  
      <LinearLayout
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"
          android:background="#00000000"
          android:orientation="vertical" />
  
  </FrameLayout>
  

no network is triggered when the background callQuestion function :

  private void callQuestion(String result) {
  		if (result == "No result") {
  			LinearLayout middleLayout = (LinearLayout) findViewById(R.id.middleLayout);
  			middleLayout.setBackgroundColor(Color.WHITE);
  			
  			View view = LayoutInflater.from(this).inflate(
  					R.layout.detail_no_result, null);
  			middleLayout.addView(view);
  		}
  	}
  

among R.layout.detail_no_result as follows:

  <?xml version="1.0" encoding="utf-8"?>
  <TextView xmlns:android="http://schemas.android.com/apk/res/android"
      android:id="@+id/txt1"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:background="#ff0"
      android:gravity="center"
      android:text="网络出问题了，点我刷新..."
      android:textSize="30sp" />
  

Why is this TextView can not fill (fill_parent) throughout middleLayout? ? ?
------ Solution ---------------------------------------- ----

LinearLayout.LayoutParams ly = new LayoutParams(LinearLayout.LayoutParams.FILL_PARENT,LinearLayout.LayoutParams.FILL_PARENT);
  middleLayout.addView(view,ly);