How to add custom view inside another custom view?

Question

I'm trying to add CustomViewBeta (an extended RelativeLayout) to CustomViewAlpha (an extended LinearLayout) -- the idea being that the CustomViewAlpha will hold a bunch of CustomViewBetas a la a ListView. No matter what I try, it doesn't work. I either see nothing -- no CustomViewBetas, or it gives me an NPE when I try setText on one of the TextViews inside the CustomViewBeta

CustomViewAlpha works fine since it's hard-coded in the Fragment's XML:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
   ...>
    <com.path.CustomViewAlpha
        android:id="@+id/customviewalpha"
        android:orientation="vertical"
        android:layout_gravity="center_vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</FrameLayout>

With the code being:

public class CustomViewAlpha extends LinearLayout {
private Context mContext;

public CustomViewAlpha (Context context) {
    super(context);
    this.mContext = context;
}

public CustomViewAlpha (Context context, AttributeSet attrs) {
    super(context, attrs);
    this.mContext = context;
}

public CustomViewAlpha (Context context, AttributeSet attrs, int defStyle){
    super(context, attrs,defStyle);
    this.mContext = context;
}

public void addCustomViewBeta(String someString){
    CustomViewBeta customViewBeta = new CustomViewBeta(mContext);
    addView(customViewBeta);
}

CustomViewBeta is not hard-coded in the Fragment's XML and get's added programmatically:

public class CustomViewBeta extends RelativeLayout{ private Context mContext;

private TextView textView;

public CustomViewBeta (Context context) {
    super(context);
    this.mContext = context;
    init();
}

public CustomViewBeta (Context context, AttributeSet attrs) {
    super(context, attrs);
    this.mContext = context;
    init();
}

public CustomViewBeta (Context context, AttributeSet attrs, int defStyle){
    super(context, attrs,defStyle);
    this.mContext = context;
    init();
}


private void init() {
    LayoutInflater.from(mContext).inflate(R.layout.customviewbeta, null, false);
    textView = (TextView) findViewById(R.id.tripleexpandablelistview_category_name);
    textView.setText("ASDASDASDAD");
}

With this XML being:

<?xml version="1.0" encoding="utf-8"?>
<com.path.CustomViewBeta
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/customviewbeta_textview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

</com.path.CustomViewBeta>

I usually get hit with a NPE on the "textView.setText("ASDASDASDAD");" line because the TextView is null. Is there something I'm missing? Should I not try to inflate an XML for the CustomViewBeta and just do it programmatically (adding the textviews one by one programmatically?)? Thanks.

Answer 1

your init is wrong

private void init() {
    LayoutInflater.from(mContext).inflate(R.layout.customviewbeta, null, false);
    textView = (TextView) findViewById(R.id.tripleexpandablelistview_category_name);
    textView.setText("ASDASDASDAD");
}

the last parameter has to be true to add the TextViewto the RelativeLayout.Also ViewGroup, has a static inflate method, so you can avoid LayoutInflater.from(mContext), you can just call inflate(mContext, R.layout.customviewbeta, this);