How to inflate XML-Layout-File correctly inside Custom ViewGroup?

Question

I want to inflate a XML-Layout-File in a custom ViewGroup Class, my Problem is that it produces just a empty screen. Doing the same in the Activity Class works fine. Here i

Answer 1

Overriding onLayout is necessary.when you create a object of ViewNumber(ViewGroup vg = new ViewNumber(this)),it is like inflating xml below:

so if you don't override onLayout,ViewNumber's onLayout can't find any child,then it will be blank.

@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
    super.onLayout(changed, left, top, right, bottom);
}

after overriding,it will use the onLayout method of ViewNumber's parent, if your codes is:

public class ViewNumber extends RelativeLayout {
...
private void initView(Context context){
        View.inflate(context, R.layout.shownumberlayout,this); 
    }
...
}

then it's like inflating xml below

there is one more RelativeLayout.To sovle this,you may write:

public class ViewNumber extends RelativeLayout {
...
private void initView(Context context){
        inflater.inflate( R.layout.login_view_layout, null );
              //change (..,this) to (..,null)
    }
...
}

However, something unexpected will happen.android:layout_xxx=".."of your xml file may change(this is why your text is put in the top left corner). To learn more and a better solution,you can see talkol' answer and fgeorgiew's comment under it :)