setContentView and findViewById

Question

After reading some related posts I already know that I have to explicitly call to setContenView before trying to find by id an element into an Activity-View-Hierarchy. I've created an Activity with an inflated view and all works fine. The problem is when I try to set another view to this activity by using the next xml and code:

<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="0dp"
android:paddingRight="0dp"
android:paddingTop="0dp"
android:paddingBottom="0dp"
android:background="#B12A6D"
tools:context=".MainActivity"
android:orientation="vertical"
>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="top"
    android:background="@drawable/bg_purple_500"
    android:layout_margin="0dp"
    >

<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/GridLayout1"
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:layout_weight="50"
        android:columnCount="4"
        android:rowCount="4"
        android:orientation="horizontal"
        tools:context=".GridXMLActivity"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="10dp"
        >

         <ImageView
            android:id="@+id/my_bnt"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/icon_new_game"
            android:contentDescription="@string/text"
            android:layout_marginTop="10dp"
            android:layout_marginLeft="20dp"
            android:layout_marginRight="20dp"
            android:layout_marginBottom="10dp"
            />
</GridLayout>

</LinearLayout>

</RelativeLayout>

code:

public class MainActivity extends ActionBarActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

}


....

protected void method_triggered_from_UI_thread() {

  // Inflate other layout...
  View view = View.inflate(this, R.layout.my_layout, null) ;
  setContentView(view);
  ImageView btn = (ImageView) findViewById(R.id.my_bnt);
  // btn is null...

}

I've tried other slight variations:

View mainView = findViewById(android.R.id.content);
LayoutInflater inflater = LayoutInflater.from(this);
View view = inflater.inflate(R.layout.my_layout, (ViewGroup) mainView, false)  ;
setContentView(view);
ImageView btn = (ImageView) view.findViewById(R.id.my_bnt);

And I always get btn == null. What am I doing wrong?

Thx

Answer 1

You could try LayoutInflater.

View inflatedView = LayoutoutInflater.from(context).inflate(R.layout, null);
setContentView(inflatedView);

Happy codings